Archive for the ‘Curious Facts’ Category

Check weather forecast from console (terminal) on GNU / Linux and FreeBSD howto

Friday, August 23rd, 2019

how to get weather forecast prognosis from command line text terminal / console on Linux and FreeBSD

Doing everything in Linux console / terminal is a question perhaps every Linux / BSD hacker wants to do as Graphical user interface and using web search or using Graphical Environment plugins is an unneded complexity + googling or duckduckgoing for weather to check your next vacation destination city has been more and more of a terrible experience (for me) as I'm not a big fan of using the OS in a GUI.
In that manner of thoughts, as a Linux console geek and hard core ASCII art fan. I was recently happy to find that  possible to check weather forecast in tty console or Linux terminal in a beautiful ascii art way easily through a Web wttr.in service – a web application weather forecast service that supports displaying the current and few days in future, weather forecast either in browser as a plain text or from the command line by simply accessing it with your favourite web access / transfer tool such as;
wget / curl or any of your favourite text browser elinks / lynx / w3m or if on *BSDs use fetch command.

 

Install Curl data transfer tool if it is not already


Wget is installed by default across most Linux distributions and fetch is present by default on BSDs, displaying it in text browser would perhaps be never used but if you decide to give it a try maybe try with elinks (to get colorful output), w3m and lynx will display a black and white results.

In case if you miss curl, install it:

On Debian distro

 

aptitude install -y curl


or Fedora

yum install -y curl


Of course to use wttr.in as it is Internet based Weather Forecast service the minimum you need to have is to have Internet connection to your Linux / BSD desktop computer.

Text based Weather Forecast Web App currently supports:

display the current weather as well as a 3-day weather forecast, split into morning, noon, evening and night

  • Temperature is displayed for morning, noon, evening and night (includes temperature range, wind speed and direction, viewing distance, precipitation amount and probability)
  • Provide results for Weather based on City / town / village location
  • Supports display of Moon Phases Forecast in calendar days
  • Supports multilingual names (Bulgarian Phonetic cyrillic / Russian and other exotic UTF-8 encodings such as Chineese and Japanese),  50+ languages are currently supported
  • Has ability for prognosis for hostname (domain) location based on an its IP GeoIP location on the Globe
  • Geographical locations / landmarks such as Lakes / Mountains etc. can be easily queried
  • Query results metrics could be configured, e.g. USCS units or EU and rest of world accepted ones (SI) metric
  • Displayed result could be either in ANSI (if from terminal / console / HTML if queried from browser or in PNG – if needed)

 

Where wttr.in could be useful ?

The best applications use, I can think of are for server (shell) / perl scripting automation purposes, it could be useful especially in TOO HOT, TOO, COLD, TOO WET location in Small and Middle sized Data Centers Green Energy (Sun Panel) Parks / Wind Energy situated Linux monitoring hosts to track possible problems of overheats or overcolding of servers due to abnormal excessive temperatures such as the ones we experienced this summer here All across in Europe or in too Cold DC locations such as heat locations Deserts in African Countries, Saudi Arabia or Chukotka or Siberia in Russia.
Other application is as a backup option to other normal Weather report services by PHP or Python scripts that fetch data, from multiple places.
Of course since this is a third party controlled service, the downtime is due to excessive connection requests, the service could get flooded and stopped working, but I guess for any Commercial use, wttr.in creator Igor Chubin would be happy to sell a specific crafted service for any end user candidates.


Here is few examples of the beautiful returned ASCII art formatted output of wttr.in.
 

1. Getting a three days Weather Forecast prognosis for city / town location

To get what is current weather in my current city of Living, Sofia Bulgaria just pass the city to the URL address

curl http://wttr.in/Sofia

text-console-wttr.in-Weather-forecast-Sofia-for-Linux

 

links http://wttr.in/Dobrich

 

curl-Linux-show--Dobrich-Weather-forecast-in-lynx-text-browser


Default links (Linux) www text browser produces ugly black and white

2. Displaying Weather forecast with wget

 

wget -O- -q http://wttr.in


getting-weather-forecast-on-linux-terminal-console-with-wget-command

If you're lazy you can even omit the http:// as wget will look for HyperText Transmission Protocol by itself

 

wget -O- -q wttr.in

 

3. Getting Forecast results for a Tourist Destination


Lets get the weather forecast for the popular tourist Bulgarian destination of the Seven Rila Lakes (near Rila Monastery), situated in the Rila Mountain BG.

 

curl http://wttr.in/Seven+Rila+Lakes

 

Console-terminal-Weather-forecast-Linux-Seven-Rila-Lakes

 

 

4. Display Forecast for a specific server IP


Displaying information on specific server IP address current situated in GeoIP database, of course could be not really true, as the IP could be just a Load Balancer a router that does NAT to some internal DMZ-ed location server, but anyways it is a cool feature.

Lets get information on what is the weather on Google Global's Public DNS server IP 8.8.8.8 so commonly used to guarantee a Windows and Linux Desktop client machines Internet connectivity.
 

curl wttr.in/@8.8.8.8

 

wttr.in-Linux-text--forecast-service-curl-screenshot Google Public DNS location weather forecast

5. Download PNG image picture from wttr.in service

 


Lets say you want to get a 3 days standard Weather forecast for the popular Black Sea Resort town in Bulgaria Pomorie (a beautiful sea city which has even a functioning 5 Monks Monastery Pomorie Monastery situated near sea coast)

 

curl http://wttr.in/Pomorie.png
 

 

–2019-08-22 20:15:51–  http://wttr.in/Pomorie.png
Resolving wttr.in (wttr.in)… 5.9.243.187
Connecting to wttr.in (wttr.in)|5.9.243.187|:80… connected.
HTTP request sent, awaiting response… 200 OK
Length: 42617 (42K) [image/png]
Saving to: ‘Pomorie.png’

Pomorie.png                                     100%[=======================================================================================================>]  41.62K  –.-KB/s    in 0.07s   

2019-08-22 20:15:52 (586 KB/s) – ‘Pomorie.png’ saved [42617/42617]

 

Note: The generated .png is again the ASCII art produced by a direct text fetch bug in pic format

 

6. Displaying Current Moon Phase


If you want to enjoy a text based Moon phase picture through wttr.in 🙂

wget -O- -q wttr.in/Moon


Display-current-Phase-of-Moon-in-terminal-console-Linux-wttr.in-service

You can also get a Moon Phase prognosis for a current future date or get a previous date phase

 

curl wttr.in/moon@2019-09-15

Full-Moon-Weather-forecast-text-console-reporting-via-wttr.in-on-Gnu_Linux


Full Moon Madness !! – Vampires are out beaware and Enjoy the ultra kewl ASCII Colorful Art 🙂
 

7. Getting help for wttr.in terminal Waether Forecast results

 

 

$ curl wttr.in/:help
Usage:

 

    $ curl wttr.in          # current location
    $ curl wttr.in/muc      # weather in the Munich airport

Supported location types:

    /paris                  # city name
    /~Eiffel+tower          # any location
    /Москва                 # Unicode name of any location in any language
    /muc                    # airport code (3 letters)
    /@stackoverflow.com     # domain name
    /94107                  # area codes
    /-78.46,106.79          # GPS coordinates

Special locations:

    /moon                   # Moon phase (add ,+US or ,+France for these cities)
    /moon@2016-10-25        # Moon phase for the date (@2016-10-25)

Units:

    m                       # metric (SI) (used by default everywhere except US)
    u                       # USCS (used by default in US)
    M                       # show wind speed in m/s

View options:

    0                       # only current weather
    1                       # current weather + 1 day
    2                       # current weather + 2 days
    A                       # ignore User-Agent and force ANSI output format (terminal)
    F                       # do not show the "Follow" line
    n                       # narrow version (only day and night)
    q                       # quiet version (no "Weather report" text)
    Q                       # superquiet version (no "Weather report", no city name)
    T                       # switch terminal sequences off (no colors)

PNG options:

    /paris.png              # generate a PNG file
    p                       # add frame around the output
    t                       # transparency 150
    transparency=…        # transparency from 0 to 255 (255 = not transparent)

Options can be combined:

    /Paris?0pq
    /Paris?0pq&lang=fr
    /Paris_0pq.png          # in PNG the file mode are specified after _
    /Rome_0pq_lang=it.png   # long options are separated with underscore

Localization:

    $ curl fr.wttr.in/Paris
    $ curl wttr.in/paris?lang=fr
    $ curl -H "Accept-Language: fr" wttr.in/paris

Supported languages:

    af da de el et fr fa hu id it nb nl pl pt-br ro ru tr uk vi (supported)
    az be bg bs ca cy cs eo es fi ga hi hr hy is ja jv ka kk ko ky lt lv mk ml nl fy nn pt pt-br sk sl sr sr-lat sv sw th te uz zh zu he (in progress)

Special URLs:

    /:help                  # show this page
    /:bash.function         # show recommended bash function wttr()
    /:translation           # show the information about the translators

 


 

 

8. Comparing two cities weather from command line

 


One useful use of wttr.in if you plan to travel from Location city A to Location city B is to compare the temperatures with a simple bash one liner script:

 

 

 

diff -Naur <(curl -s http://wttr.in/Sofia ) <(curl -s http://wttr.in/Beograd )

 

 

9. Using ansiweather command to get Weather Temperature / Wind / Humidity in one line beuatiful text

 


If you go and install answeather Linux package

 

apt-get install –yes ansiweather


You will get a shell script wrapper with ANSI colors and Unicode symbols support. Weather data comes from OpenWeatherMap, this is useful if wttr.in is not working due to some URL malfunction (due to service is DoS-ed) etc.

 

ansiweather -l Atina

 

ansiweather-Atina-weather-forecast-result-linux-text-console

Lets use ansiweather to print the weather prognosis for upcoming 5 days for near port of Burgas, BG
 

ansiweather -F -l Burgas

ansiweather-print-weather-forecast-prognosis-for-5-days-in-Linux-text-terminal

 

10. Get all Weather current forecast for each Capital in the world


You can download and use this simple plain text file list of All Country Capitals in the World (country-capitals-all-world.txt) with ansiweather and a bash loop to get displayed each and every current day Weather Forecast in the World, here is how:

 

while read line; do ansiweather -l $line; sleep 3; done < country-capitals-all-world.txt


ansiweather-all-countires-capitals-result

As you can see some of the very exotic third world capitals does not return data so 'ERROR: Cannot fetch weather data' is returned.


You can also substitute ansiweather with curl wttr.in/$line to do get the beautiful ASCII art 3 days weather forecast via wttr.in

 

while read line; do curl http://wttr.in/$line; sleep 3; done < country-capitals-all-world.txt


I'll be happy to know other nice ASCII Art supporting Web service to enjoy from text terminal on Linux (nomatter useful or) just funny joyful prank maniacal pranks such as Watching text ASCII version remake of Star Wars Classic Movie by simply telnetting to towel.blinkenlights.nl (if you haven't so just telnet and enjoy the streamed ASCIIs ! 🙂

 

telnet towel.blinkenlights.nl

 

watch-star-wars-ascii-art-version-remake-online-with-telnet-on-linux-console-terminal

 

Talking about fun and ASCII, its worthy to mention hollywood Linux package

hipo@jeremiah:~/Desktop$ apt-cache show hollywood|grep -i desc -A 3
Description-en: fill your console with Hollywood melodrama technobabble
 This utility will split your console into a multiple panes of genuine
 technobabble, perfectly suitable for any Hollywood geek melodrama.
 It is particularly suitable on any number of computer consoles in the


Description-md5: 768f44c76220ea2b35f855ea34c8bc35
Homepage: http://launchpad.net/hollywood
Section: games
Priority: optional


Once installed on Debian with:

aptitude install -y hollywood

You can get in a rapid manner plenty of tmux (screen like – virtual console emulator) split screen statistics about your notebook / workstation / server CPU usage, mlocate.db status, info about plugged in machine voltage, Speedometer (statistics about Network bandwidth usage), System load avarage (CPU Count, Memory Utilization) and some other random info coming out of dmesg kernel log and more. The information displayed in splitted windows changes rapidly and (assuming you run it at home Desktop with a soundblaster) and not remotely, a james bond Agent 007 soundtrack is played on the back, that brings up one's adrenaline and makes it look even cooler.

hollywood-melodrama-technobubble-split-console-multiple-panes-for-genuine-technobubble

To give you an idea what to expect, here is shot of /usr/games/hollywood (the program start binary location) on Debian GNU / Linux running, Enjoy! 🙂
 

Why du and df reporting different on a filesystem / How to fix inconsistency between used space on FS and disk showing full strangeness

Wednesday, July 24th, 2019

linux-why-du-and-df-shows-different-result-inconsincy-explained-filesystem-full-oddity

If you're a sysadmin on a large server environment such as a couple of hundred of Virtual Machines running Linux OS on either physical host or OpenXen / VmWare hosted guest Virtual Machine, you might end up sometimes at an odd case where some mounted partition mount point reports its file use different when checked with
df
cmd than when checked with du command, like for example:
 

root@sqlserver:~# df -hT /var/lib/mysql
Filesystem   Type  Size Used Avail Use% Mounted On
/dev/sdb5      ext4    19G  3,4G    14G  20% /var/lib/mysql

Here the '-T' argument is used to show us the filesystem.

root@sqlserver:~# du -hsc /var/lib/mysql
0K    /var/lib/mysql/
0K    total

 

1. Simple debug on what might be the root cause for df / du inconsistency reporting

 

Of course the basic thing to do when in that weird situation is to be totally shocked how this is possible and to investigate a bit what is the biggest first level sub-directories that eat up the space on the mounted location, with du:

 

# du -hkx –max-depth=1 /var/lib/mysql/|uniq|sort -n
4       /var/lib/mysql/test
8       /var/lib/mysql/ezmlm
8       /var/lib/mysql/micropcfreak
8       /var/lib/mysql/performance_schema
12      /var/lib/mysql/mysqltmp
24      /var/lib/mysql/speedtest
64      /var/lib/mysql/yourls
144     /var/lib/mysql/narf
320     /var/lib/mysql/webchat_plus
424     /var/lib/mysql/goodfaithair
528     /var/lib/mysql/moonman
648     /var/lib/mysql/daniel
852     /var/lib/mysql/lessn
1292    /var/lib/mysql/gallery

The given output is in Kilobytes so it is a little bit hard to read, if you're used to Mbytes instead, do

 

 # du -hmx –max-depth=1 /var/lib/mysql/|uniq|sort -n|less

 

I've also investigated on the complete /var directory contents sorted by size with:

 

 # du -akx ./ | sort -n
5152564    ./cache/rsnapshot/hourly.2/localhost
5255788    ./cache/rsnapshot/hourly.2
5287912    ./cache/rsnapshot
7192152    ./cache


Even after finding out the bottleneck dirs and trying to clear up a bit, continued facing that inconsistently shown in two commands and if you're likely to be stunned like me and try … to move some files to a different filesystem to free up space or assigned inodes with a hope that shown inconsitency output will be fixed as it might be caused  due to some kernel / FS caching ?? and this will eventually make the mounted FS to refresh …

But unfortunately, if you try it you'll figure out clearing up a couple of Megas or Gigas will make no difference in cmd output.

In my exact case /var/lib/mysql is a separate mounted ext4 filesystem, however same issue was present also on a Network Filesystem (NFS) and thus, my first thought that this is caused by a network failure problem or NFS bug turned to be wrong.

After further short investigation on the inodes on the Filesystem, it was clear enough inodes are available:
 

# df -i /var/lib/mysql
Filesystem       Inodes  IUsed   IFree IUse% Mounted on
/dev/sdb5      1221600  2562 1219038   1% /var/lib/mysql

 

So the filled inodes count assumed issue also has been rejected.
P.S. (if you're not well familiar with them read manual, i.e. – man 7 inode).
 

– Remounting the mounted filesystem

To make sure the filesystem shown inconsistency between du and df is not due to some hanging network mount or bug, first logical thing I did is to remount the filesytem showing different in size, in my case this was done with:
 

# mount -o remount,rw -t ext4 /var/lib/mysql

For machines with NFS remote mounted storage locations, used:

# mount -o remount,rw -t nfs /var/www


FS remount did not solved it so I continued to ponder what oddity and of course I thought of a workaround (in case if this issues are caused by kernel bug or OS lib issue) reboot might be the solution, however unfortunately restarting the VMs was not a wanted easy to do solution, thus I continued investigating what is wrong …

Next check of course was to check, what kind of network connections are opened to the affected hosts with:
 

# netstat -tupanl


Did not found anything that might point me to the reported different Megabytes issue, so next step was to check what is the situation with currently opened files by running processes on the weird df / du reported systems with lsof, and boom there I observed oddity such as multiple files

 

# lsof -nP | grep '(deleted)'

COMMAND   PID   USER   FD   TYPE DEVICE    SIZE NLINK  NODE NAME
mysqld   2588  mysql    4u   REG 253,17      52     0  1495 /var/lib/mysql/tmp/ibY0cXCd (deleted)
mysqld   2588  mysql    5u   REG 253,17    1048     0  1496 /var/lib/mysql/tmp/ibOrELhG (deleted)
mysqld   2588  mysql    6u   REG 253,17       777884290     0  1497 /var/lib/mysql/tmp/ibmDFAW8 (deleted)
mysqld   2588  mysql    7u   REG 253,17       123667875     0 11387 /var/lib/mysql/tmp/ib2CSACB (deleted)
mysqld   2588  mysql   11u   REG 253,17       123852406     0 11388 /var/lib/mysql/tmp/ibQpoZ94 (deleted)

 

Notice that There were plenty of '(deleted)' STATE files shown in memory an overall of 438:

 

# lsof -nP | grep '(deleted)' |wc -l
438


As I've learned a bit online about the problem, I found it is also possible to find deleted unlinked files only without any greps (to list all deleted files in memory files with lsof args only):

 

# lsof +L1|less


The SIZE field (fourth column)  shows a number of files that are really hard in size and that are kept in open on filesystem and in memory, totally messing up with the filesystem. In my case this is temp files created by MYSQLD daemon but depending on the server provided service this might be apache's www-data, some custom perl / bash script executed via a cron job, stalled rsync jobs etc.
 

2. Check all the list open files with the mysql / root user as part of the the server filesystem inconsistency debugging with:

 

– Grep opened files on server by user

# lsof |grep mysql
mysqld    1312                       mysql  cwd       DIR               8,21       4096          2 /var/lib/mysql
mysqld    1312                       mysql  rtd       DIR                8,1       4096          2 /
mysqld    1312                       mysql  txt       REG                8,1   20336792   23805048 /usr/sbin/mysqld
mysqld    1312                       mysql  mem       REG               8,21      24576         20 /var/lib/mysql/tc.log
mysqld    1312                       mysql  DEL       REG               0,16                 29467 /[aio]
mysqld    1312                       mysql  mem       REG                8,1      55792   14886933 /lib/x86_64-linux-gnu/libnss_files-2.28.so

 

# lsof | grep root
COMMAND    PID   TID TASKCMD          USER   FD      TYPE             DEVICE   SIZE/OFF       NODE NAME
systemd      1                        root  cwd       DIR                8,1       4096          2 /
systemd      1                        root  rtd       DIR                8,1       4096          2 /
systemd      1                        root  txt       REG                8,1    1489208   14928891 /lib/systemd/systemd
systemd      1                        root  mem       REG                8,1    1579448   14886924 /lib/x86_64-linux-gnu/libm-2.28.so

Other command that helped to track the discrepancy between df and du different file usage on FS is:
 

# du -hxa  / | egrep '^[[:digit:]]{1,1}G[[:space:]]*'
 

 

3. Fixing large files kept in memory filesystem problem


What is the real reason for ending up with this file handlers opened by running backgrounded programs on the Linux OS?
It could be multiple  but most likely it is due to exceeded server / client interactions or breaking up RAM or HDD drive with writing plenty of logs on the FS without ending keeping space occupied or Programming library bugs used by hanged service leaving the FH opened on storage.

What is the solution to file system files left in memory problem?

The best solution is to first fix custom script or hanged service and then if possible to simply restart the server to make the kernel / services reload or if this is not possible just restart the problem creation processes.

Once the process is identified like in my case this was MySQL on systemd enabled newer OS distros, just do:

 

 

# systemctl restart mysqld.service


or on older init.d system V ones:

# /etc/init.d/service restart


For custom hanged scripts being listed in ps axuwef you can grep the pid and do a kill -HUP (if the script is written in a good way to recognize -HUP and restart the sub-running process properly – BE EXTRA CAREFUL IF YOU'RE RESTARTING BROKEN SCRIPTS as this might cause your running service disruptions …).

# pgrep -l script.sh
7977 script.sh


# kill -HUP PID

 

Now finally this should either mitigate or at best case completely solve the reported disagreement between df and du, after which the calculated / reported disk space should be back to normal and show up approximately the same (note that size changes a bit as mysql service is writting data) constantly extending the size between the two checks.

 

# df -hk /var/lib/mysql; du -hskc /var/lib/mysql
Filesystem       Inodes  IUsed   IFree IUse% Mounted on
/dev/sdb5        19097172 3472744 14631296  20% /var/lib/mysql
3427772    /var/lib/mysql
3427772    total

 

What we learned?

What I've explained in this article is why and how it comes that 'zoombie' files reside on a filesystem
appearing to be eating disk space on a mounted local or network partition, giving strange inconsistent
reports, leading to system service disruptions and impossibility to have correctly shown information on used
disk space on mounted drive.

I went through with some standard logic on debugging service / filesystem / inode issues up explainat, that led me to the finding about deleted files being kept in filesystem and producing the filesystem strange sized / showing not correct / filled even after it was extended with tune2fs and was supposed to have extra 50GBs.

Finally it was explained shortly how to HUP / restart hanging script / service to fix it.

Some few good readings that helped to fix the issue:

What to do when du and df report different usage is here
df in linux not showing correct free space after file removal is here
Why do “df” and “du” commands show different disk usage?
 

Reset gnome forgotten keyring password – Fix annoying reoccuring keyring password prompt

Wednesday, September 26th, 2018

gnome-keyring-password-error-fix-solution-howto-gnupg-error-after-changing-user-password-linux-desktop-user

If you're on Debian Linux and have a user account and you changed the password you might be unpleasantly surprised by a constantly occuring prompt to reinput the keyring stored old password.
You might be wondering how to reset the gnome keyring password to stop that annoying pop-up prompt from bittering your days.
The simplest fix is to delete all stored passwords and reset the keyring stored values. That's in case if you don't have other important passwords saved.

This is done by simply creating a backup of the old keyring just in case if you have something important stored you can do that with:

 

cd ~/.local/share/keyrings/
cp login.keyring login.keyring.backup

 


Then delete the keyring store file:

 

rm  -f ~/.local/share/keyrings/login.keyring

 

Under some GNU / Linux distrubutions such as Linux Mint deleting the keyring file will not work on such an alternative method is to use seahorse (a frontend program to GnuPG (GNU Privacy Guard), that is doing key management  for GNOME desktop users.

 

hipo@jericho:~$ seahorse

 

seahorse-gnu-gpg-and-password-management-gui-tool-gnome-desktop-environment-debian-linux-screenshot
 

For older Linux distributions like Ubuntu 12.10 e.g. in GNOME 2, the correct path to keyring file is ~/.gnome2/keyrings/
 

rm -f ~/.gnome2/keyrings/*

 

 

Lenovo ThinkCentre Edge as an External monitor with Debian Linux on Thinkpad T420 / How to use ThinkCentre Edge as external display on Linux

Saturday, September 22nd, 2018

thinkcentre-use-as-external-monitor-on-debian-gnu-linux-ubuntu

Here is a case I bring my Thinkpad T420 notebook to office place and there was plenty of monitors free but all were quite modern and had support only for Display Port / DVI and HDMI (High Definition Multimedia Interface), e.g. there was no Monitor to support regular VGA port …

 I've conntected my Debian 9 Stretch Linux with a DisplayPort cable to one of the LG monitors but the external monitor video screen did not raised the screen kept  black just like nothing is connected to it.

So i did a quick research online to see whether and how I can make the display port on Lenovo thinkpad t420 work with Linux after consulting few resources online e.g. Hacksr Display Port on Thinkpad T420 and Nvidia Optimus  this post in Ubuntu Forums as well as the official documentation about DisplayPort and Linux on Thinkpad's official documentation ThinkWiki it turned out the T420 Thinkpads have issues with Displayport and Linux and the only solution proposed was to use the second Nvidia Optimus card instead of the integrated display adapter, I however am not sure whether my notebook have this Nvidia at all and did not have time for too much hacking to make it work.

I decided to take a more simple approach and try to use the good old school VGA port protocol with one of the 2 ThinkCentre Edge  m93z stations that were hanging around in the office, in case you never heard of ThinkCentre Edge this is (an integrated computer and monitor in a thin display a kind of cheap PC alternative from Lenovo to iMacs (all in one Macintosh Desktop computer) .

ThinkCentre_Edge_computer-in-monitor-desktop-like-iMac-from_Lenovo

I saw some skeptical looks from colleagues but I with my usual stubborness gave it a try and after a bit of quick research I got it working on Linux ! 🙂
 

If you're wondering whether THINKCENTRE Edge can be used with VGA port as External Display to a Linux powered Laptop the Answer is YES  !!! 🙂


To make it working, 
All you have to do it is configure it as External display from ThinkCentre (OSD) display menu. 

thinkcentre-menus-osd-menu-screenshot

But wait the joy was not so full, even though the ThinkCentre displayed my GNOME FlashBack background picture on its screen it did not show my actual GNOME Menus (Application, Places and Desktop) just like shown in below screenshot ..

Debian-9-1-Stretch-Linux-background-default-picture

I could see fine the ThinkCentre monitor showing normally in xrandr command which is the tool to always check first if you're new on Linux and want to check settings regarding your Notebook display settings / Desktop PC exnternal display settings on Linux , the output of  xrandr is below.
 

hipo@jericho:~$ xrandr

 

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096 LVDS1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm 1920x1200 60.0 +   1600x1200 60.0   1680x1050 60.0   1280x1024 76.0 75.0 72.0 60.0   1440x900 75.0 59.9   1152x864 75.0 1024x768 60.0*+ 800x600 60.3 56.2 640x480 59.9 VGA1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 519mm x 324mm 1920x1200 60.0 + 1600x1200 60.0 1680x1050 60.0 1280x1024 76.0 75.0 72.0 60.0 1440x900 75.0 59.9 1152x864 75.0 1024x768 75.1 70.1 60.0* 832x624 74.6 800x600 72.2 75.0 60.3 640x480 72.8 75.0 66.7 60.0 720x400 70.1

I also gave a try to arandr which is a simple GUI interface to xrandr, i.e.:
 

root@jericho:~# apt-get install –yes -qq arandr
root@jericho:~# exit
hipo@jericho:~$  arandr


arandr-debian-gnu-linux-screenshot

Unfortunately trying to turn on / off the VGA monitor shown in above screenshot using arandr and saving did not produced any positive results, as the ThinkCentre Edge used as external monitor kept being showing only my Debian Linux background.

During my attempts to make it working I stumbled upon driconf a configuration applet program for Direct Rendering Infrastructure (DRI).

driconf-screenshot-linux

 

 

I also gave a try to default gnome-control-center Monitor settings tool but I couldn't turn off the notebook display in order to make the ThinkCentre Edge my primary display.

Finally after some more investigation online, I found how to switch on my Notebook display by running below xrandr command
 

xrandr –output LVDS-1 –off


Just in case if you need to re-enable (on) the LVDS-1 use 

 

xrandr -d :0 –output LVDS –auto​

Create user and password on Linux non interactive and add it to sudo a tiny Dev Ops script

Thursday, September 20th, 2018

Bash-Final-the-Bourne-again-shell-logo
A common task for SysAdmins who managed a multitude of servers remotely via Secure Shell was to add a user and assign password by using a script, this was sometimes necessery to set-up some system users and create access for university users on 10 / 20 testing Linux servers.

Nowadays this task of adding user to a list of remote servers and granting the new user superuser permissions through /etc/sudoers is practiced heavily by the so called Dev Ops (Just another Buziness Word for Senior System Admiistrators with good scripting skills and a little bit of development experience – same game different name.

The Dev Ops System Integration Engineers use this useful add non-interactive user via SSH in Cloud environments in order to prepare superuser (root permissioned through /etc/sudoers) user, that is later be used for lets say deployment on a few hundred of servers of lets say LAMP (Linux + Apache + MySQL + PHP) or LEMP (Linux NGINX MySQL PHP) or Software Load Balancer HAProxy  balacing for MySQL clusters / Nginx Application servers / JIRAs etc, through a Playbook script with some deployment automation tool such as Ansible.

Well enough talk here is the few lines of code which does create a user locally:
 

linux:~# apt-get install –yes sudo
linux:~# useradd devops –home /home/devops -s /bin/bash
linux:~# mkdir /home/devops
linux:~# chown -R devops:devops /home/devops
linux:~# echo 'username:testpass' | chpasswd


Though this lines could be invoked easily by passing it as arguments via ssh it is often unhandy to run them on remote host, because some of the remote hosts against executed, might have already the user existent with granted permissions for sudo

Thus a much better way to do things is use below script and first upload it to remote servers by running the scp command in a loop:

while read line; do
scp  root@$i:/root/
ssh "
create_user_noninteractive_and_add_to_sudoers.sh"
done < servers_list.txt


Where servers_list.txt contains a list of remote IPs:

#!/bin/bash
# Create new user/group and add nopasswd login to sudoers
# Author: Georgi Georgiev
# has to be run sa root – sudo devops
# hipo@pc-freak.net

 

u_id='devops';
g_id='devops';
pass='testpass';
sudoers_f='/etc/sudoers';

check_install_sudo ()  {
if [ $(dpkg –get-selections | cut -f1|grep -E ‘^sudo’) ]; then
apt-get install –yes sudo
else
        printf "Nothing to do sudo installed";
fi
}

check_install_user () {

if [ “$(sed -n “/$u_id/p” /etc/passwd|wc -l)” -eq 0 ]; then
apt-get install –yes sudo
apt-get install –yes sudo
useradd $u_id –home /home/$u_id
mkdir /home/$u_id
chown -R $u_id:$g_id /home/$u_id
echo "$u_id:$pass" | chpasswd
cp -rpf /etc/bash.bashrc /home/$u_id
if [ “$(sed -n “/$u_id/p” $sudoers_f|wc -l)” -eq “0” ]; then
echo "$u_id ALL=(ALL) NOPASSWD: ALL" >> $sudoers_f
else
        echo "$u_id existing. Exiting ..";
        exit 1;
fi

else
        echo "Will do nothing because $u_id exists";
fi

}

check_install_sudo;
check_install_user;


By the way this task was the simplest task given by a Company where I applied for a Dev Ops System Engineer, so I hope this will help someone else too.

P.S. If you prefer Shell scripts (even though much harder, time consuming etc.) as a mean of automation as an alternative to Ansible / Chef I suggest you check out and perhaps try to do the task with http://fuckingshellscripts.org 🙂

Install Slack and Mattermost clients for Start Up Business communication on Linux

Wednesday, September 19th, 2018

install-slack-and-mattermost-clients-for-start-up-business-communication-on-Linux
Many businesses nowadays are lookig for alternatives to the Microsoft dominated market of communication – Skype / Skype for Business Chat Audio and Video desktop client.
The two are the defacto standard for most of Corporate Businesses and is heavily used across most largest Corporations (companies) such as IBM / Xeror / DXC / CSC / Oracle / SAP / Microsoft / Amazon / Adobe … the list goes on and on.

However even though Skype is so easy to use across Microsoft Domain connected Computers the many start-up companies of today often try to avoid its use. The reason, well Skype is totally Proprietary non-transparent and by using it you probably get spied by Microsoft the CIA and God knows how many other Country Agencies. Besides that Skype has a bad history often had problems with Audio (Linux microphone and Video settings) in Free Software (Linux, FreeBSD etc.) realm and even though nowdays situation is improving and Skype Video / Audio runs fine on GNU / Linuxes its Skype for Business has no working release by Microsoft and has left-up Free Software users and Staring Business companies platform of the size of 20 to 1000 people  that choose Linux as a main Desktop / Work had to look for other ways to communicate internally within company and with clients.

Jabber XMPP communication protocol has been one alternative for a long time and historically many compainies that were running out of Skype use for their work often were using Small internally company hosted jabber servers, however as Jabber's  communication clients such as Gajim development is lagging behind seriously over the last 7 years and it prooved so buggy many businesses were looking for ways to avoid it.

Slack_Technologies_-corporate-communication-alternative-to-skype-Logo.png


Slack is multi platform just like Skype and has versions for Linux / Windows for macOS but its power comes mostly because most of its users use it via Skype Web Client (while Skype is a Desktop app and heavily used in Web Browser.

slack-web-communication-client-in-webbrowser-screenshot

Slack reminds in a what of things to the good old IRC chats and has channels in a similar fashion, it support Audio conversations but unfortunately at the moment didn't support Video.

The emergency of New Age of Computing and the quick adoption of Clouds as an aim to cut business costs put Jabber totally out of the game and in the niche and in August 2013 on the scene raised Slack (Team Messaging) which is an acronymi of (Searchable Log of All Conversations and Knowledge) – a cloud-based set of proprietary team collaboration tools and services, founded by Stewart Butterfield for the purpose of online Game (now defunct) called Glitch.

asana-for-slack-integration-2018-2-linux
The problem with Slack is that it is a freemium product, whose main paid features are the ability to search more than 10,000 archived messages (the ordinary free version allows the user to make up to 10000 searches in chat history), the paid Slack versions adds also unlimited apps and integrations and theoretically unlimited number of users (though this is seriously doubtful).

slack-10000-messages-per-user-limitation-shot

One very handy feature of Slack is its integration with "The World's Leading Software Development Platform" – GitHub .

To solve the problem with the little amount of Slack Chat history in Users conversations many Start-Up Business Companies do use Slack as a communication media with Clients and does often use as a communication Media another very popular Cloud messaging Open Source Software called Mattermost deploys to Cloud infrastruture but is at IT control of your company or your hired support and not third party vendor supports, making it a great communication tool for small and mid-sized companies who want to save money of purchasing a special server and hiring an admin or paying for one to support it all the time but instead directly use their Cloud account and deploy it there.

Mattermost is capable to Reach anyone, anywhere on any device. From the airport to data center, safely connect teams with EMM apps, hybrid cloud deployment and enterprise-grade flexibility to meet the unique needs of enterprise.

It is capable to Integrate with existing applications and build new workflows and empower your teams especially operations and DevOps – to perform faster and effectively. Mattermost


To install Slack on Linux:

Go and Download slack from Slack Linux download (the DEB / RPM 64 bit package)

As of time of writting this article latest Slack Desktop packages are: slack-desktop-3.3.1-amd64.deb and slack-3.3.1-0.1.fc21.x86_64.rpm

Depending on the type of Linux distribution install it with dpkg or rpm

1. Installing Slack Desktop client on Debian / Ubuntu Linux

On Debian / Ubuntu / Mint install Slack with:

 

root@ubuntu:~# dpkg -i slack-desktop-*.deb


For Ubuntu users there is also unofficial third-party Slack app ScoudCloud

it integrates well with Ubuntu Unity desktop (which I personally dislike 🙂 ) and gives you some extra goodies such as showing in an Unity manner unread message count, notification, bubbles, unity quicklists for fast-switching between Slack channels etc.

2. Installing Slack Desktop client on Redhat / Fedora / CentOS Linux

On Redhat / Fedora / CentOS install it with:

 

[root@fedora ~]:# rpm -ivh slack-*.rpm

 


3. Installing Mattermost Desktop client on Linux

mattermost-open-source-communication-in-the-cloud

Download Mattermost Linux package from download URL here

As of time of writting the DEB versions are mattermost-desktop-4.1.2-linux-amd64.deb mattermost-desktop-4.1.2-linux-i386.deb and there is no official RPM package for Fedora / CentOS users however I guess the .deb package can easily be converted to .rpm with alien tool.

To install Mattermost on Debian (in moment of writting September 2018):

 

root@debian:~# wget https://releases.mattermost.com/desktop/4.1.2/mattermost-desktop-4.1.2-linux-amd64.deb

 

root@debian:~# dpkg -i mattermost-desktop-4.1.2-linux-amd64.deb


mattermost-linux-client-2-screenshot

Mattermost supports file attachment (send) / Video previews (you can play sent Web videos directly within the Mattermost client) and on experimental level even supports Video and Audio Calls.

mattermost-linux-client-screenshot-1

mattermost-markdown-help-linux-screenshot

One nice feature of Mattermost for those who love coding is using tags to format messages

There is plenty of features of Mattermost among the best ones are integrations Private Cloud open source integrations (Jira, Jenkins, Bots, clients), supports Webhooks, Restful APIS, CLI and Public Cloud connections via Zapier – a connect and uatomate workflows e.g. gives you ability to move info between web apps automatically.

Mail send from command line on Linux and *BSD servers – useful for scripting

Monday, September 10th, 2018

mail-send-email-from-command-line-on-linux-and-freebsd-operating-systems-logo

Historically Email sending has been very different from what most people use it in the Office, there was no heavy Email clients such as Outlook Express no MX Exchange, no e-mail client capabilities for Calendar and Meetings schedule as it is in most of the modern corporate offices that depend on products such as Office 365 (I would call it a connectedHell 365 days a year !).

There was no free webmail and pop3 / imap providers such as Mail.Yahoo.com, Gmail.com, Hotmail.com, Yandex.com, RediffMail, Mail.com the innumerous lists goes and on.
Nope back in the day emails were doing what they were originally supposed to like the post services in real life simply send and receive messages.

For those who remember that charming times, people used to be using BBS-es (which were basicly a shared set-up home system as a server) or some of the few University Internal Email student accounts or by crazy sysadmins who received their notification and warnings logs about daemon (services) messages via local DMZ-ed network email servers and it was common to read the email directly with mail (mailx) text command or custom written scripts … It was not uncommon also that mailx was used heavily to send notification messages on triggered events from logs. Oh life was simple and clear back then, and even though today the email could be used in a similar fashion by hard-core old school sysadmins and Dev Ops / simple shell scriptings tasks or report cron jobs such usage is already in the deep history.

The number of ways one could send email in text format directly from the GNU / Linux / *BSD server to another remote mail MTA node (assuming it had properly configured Relay server be it Exim or Postifix) were plenty.

In this article I will try to rewind back some of the UNIX history by pinpointing a few of the most common ways, one used to send quick emails directly from a remote server connection terminal or lets say a cheap VPS few cents server, through something like (SSH or Telnet) etc.
 

1. Using the mail command client (part of bsd-mailx on Debian).
 

In my previous article Linux: "bash mail command not found" error fix
I ended the article with a short explanation on how this is done but I will repeat myself one more time here for the sake of clearness of this article.

root@linux:~# echo "Your Sample Message Body" | mail -s "Whatever … Message Subject" remote_receiver@remote-server-email-address.com


The mail command will connect to local server TCP PORT 25 on local configured MTA and send via it. If the local MTA is misconfigured or it doesn't have a proper MX / PTR DNS records etc. or not configure as a relay SMTP remote mail will not get delivered. Sent Email should be properly delivered at remote recipient address.

How to send HTML formatted emails using mailx command on Linux console / terminal shell using remote server through SSH ?

Connect to remote SSH server (VPS), dedicated server, home Linux router etc. and run:

 

root@linux:~# mailx -a 'Content-Type: text/html'
      -s "This is advanced mailx indeed!" < email_content.html
      "first_email_to_send_to@gmail.com, mail_recipient_2@yahoo.com"

 


email_content.html should be properly formatted (at best w3c standard compliant) HTML.

Here is an example email_content.html (skeleton file)

 

    To: your_customer@gmail.com
    Subject: This is an HTML message
    From: marketing@your_company.com
    Content-Type: text/html; charset="utf8"

    <html>
    <body>
    <div style="
        background-color:
        #abcdef; width: 300px;
        height: 300px;
        ">
    </div>
Whatever text mixed with valid email HTML tags here.
    </body>
    </html>


Above command sends to two email addresses however if you have a text formatted list of recipients you can easily use that file with a bash shell script for loop and send to multiple addresses red from lets say email_addresses_list.txt .

To further advance the one liner you can also want to provide an email attachment, lets say the file email_archive.rar by using the -A email_archive.rar argument.

 

root@linux:~# mailx -a 'Content-Type: text/html'
      -s "This is advanced mailx indeed!" -A ~/email_archive.rar < email_content.html
      "first_email_to_send_to@gmail.com, mail_recipient_2@yahoo.com"

 

For those familiar with Dan Bernstein's Qmail MTA (which even though a bit obsolete is still a Security and Stability Beast across email servers) – mailx command had to be substituted with a custom qmail one in order to be capable to send via qmail MTA daemon.
 

2. Using sendmail command to send email
 

Do you remember that heavy hard to configure MTA monster sendmail ? It was and until this very day is the default Mail Transport Agent for Slackware Linux.

Here is how we were supposed to send mail with it:

 

[root@sendmail-host ~]# vim email_content_to_be_delivered.txt

 

Content of file should be something like:

Subject: This Email is sent from UNIX Terminal Email

Hi this Email was typed in a file and send via sendmail console email client
(part of the sendmail mail server)

It is really fun to go back in the pre-history of Mail Content creation 🙂

 

[root@sendmail-host ~]# sendmail -v user_name@remote-mail-domain.com  < /tmp/email_content_to_be_delivered.txt

 

-v argument provided, will make the communication between the mail server and your mail transfer agent visible.
 

3. Using ssmtp command to send mail
 

ssmtp MTA and its included shell command was used historically as it was pretty straight forward you just launch it on the command line type on one line all your email and subject and ship it (by pressing the CTRL + D key combination).

To give it a try you can do:

 

root@linux:~# apt-get install ssmtp
Reading package lists… Done
Building dependency tree       
Reading state information… Done
The following additional packages will be installed:
  libgnutls-openssl27
The following packages will be REMOVED:
  exim4-base exim4-config exim4-daemon-heavy
The following NEW packages will be installed:
  libgnutls-openssl27 ssmtp
0 upgraded, 2 newly installed, 3 to remove and 1 not upgraded.
Need to get 239 kB of archives.
After this operation, 3,697 kB disk space will be freed.
Do you want to continue? [Y/n] Y
Get:1 http://ftp.us.debian.org/debian stretch/main amd64 ssmtp amd64 2.64-8+b2 [54.2 kB]
Get:2 http://ftp.us.debian.org/debian stretch/main amd64 libgnutls-openssl27 amd64 3.5.8-5+deb9u3 [184 kB]
Fetched 239 kB in 2s (88.5 kB/s)         
Preconfiguring packages …
dpkg: exim4-daemon-heavy: dependency problems, but removing anyway as you requested:
 mailutils depends on default-mta | mail-transport-agent; however:
  Package default-mta is not installed.
  Package mail-transport-agent is not installed.
  Package exim4-daemon-heavy which provides mail-transport-agent is to be removed.

 

(Reading database … 169307 files and directories currently installed.)
Removing exim4-daemon-heavy (4.89-2+deb9u3) …
dpkg: exim4-config: dependency problems, but removing anyway as you requested:
 exim4-base depends on exim4-config (>= 4.82) | exim4-config-2; however:
  Package exim4-config is to be removed.
  Package exim4-config-2 is not installed.
  Package exim4-config which provides exim4-config-2 is to be removed.
 exim4-base depends on exim4-config (>= 4.82) | exim4-config-2; however:
  Package exim4-config is to be removed.
  Package exim4-config-2 is not installed.
  Package exim4-config which provides exim4-config-2 is to be removed.

Removing exim4-config (4.89-2+deb9u3) …
Selecting previously unselected package ssmtp.
(Reading database … 169247 files and directories currently installed.)
Preparing to unpack …/ssmtp_2.64-8+b2_amd64.deb …
Unpacking ssmtp (2.64-8+b2) …
(Reading database … 169268 files and directories currently installed.)
Removing exim4-base (4.89-2+deb9u3) …
Selecting previously unselected package libgnutls-openssl27:amd64.
(Reading database … 169195 files and directories currently installed.)
Preparing to unpack …/libgnutls-openssl27_3.5.8-5+deb9u3_amd64.deb …
Unpacking libgnutls-openssl27:amd64 (3.5.8-5+deb9u3) …
Processing triggers for libc-bin (2.24-11+deb9u3) …
Setting up libgnutls-openssl27:amd64 (3.5.8-5+deb9u3) …
Setting up ssmtp (2.64-8+b2) …
Processing triggers for man-db (2.7.6.1-2) …
Processing triggers for libc-bin (2.24-11+deb9u3) …

 

As you see from above output local default Debian Linux Exim is removed …

Lets send a simple test email …

 

hipo@linux:~# ssmtp user@remote-mail-server.com
Subject: Simply Test SSMTP Email
This Email was send just as a test using SSMTP obscure client
via SMTP server.
^d

 

What is notable about ssmtp is that even though so obsolete today it supports of STARTTLS (email communication encryption) that is done via its config file

 

/etc/ssmtp/ssmtp.conf

 

4. Send Email from terminal using Mutt client
 

Mutt was and still is one of the swiff army of most used console text email clients along with Alpine and Fetchmail to know more about it read here

Mutt supports reading / sending mail from multiple mailboxes and capable of reading IMAP and POP3 mail fetch protocols and was a serious step forward over mailx. Its syntax pretty much resembles mailx cmds.

 

root@linux:~# mutt -s "Test Email" user@example.com < /dev/null

 

Send email including attachment a 15 megabytes MySQL backup of Squirrel Webmail

 

root@linux:~# mutt  -s "This is last backup small sized database" -a /home/backups/backup_db.sql user@remote-mail-server.com < /dev/null

 


5. Using simple telnet to test and send email (verify existence of email on remote SMTP)
 

As a Mail Server SysAdmin this is one of my best ways to test whether I had a server properly configured and even sometimes for the sake of fun I used it as a hack to send my mail 🙂
telnet is and will always be a great tool for doing SMTP issues troubleshooting.
 

It is very useful to test whether a remote SMTP TCP port 25 is opened or a local / remote server firewall prevents connections to MTA.

Below is an example connect and send example using telnet to my local SMTP on pc-freak.net (QMail powered (R) 🙂 )

sending-email-using-telnet-command-howto-screenshot

 

root@pcfreak:~# telnet localhost 25
Trying 127.0.0.1…
Connected to localhost.
Escape character is '^]'.
220 This is Mail Pc-Freak.NET ESMTP
HELO mail.pc-freak.net
250 This is Mail Pc-Freak.NET
MAIL FROM:<hipo@pc-freak.net>
250 ok
RCPT TO:<roots_bg@yahoo.com>
250 ok
DATA
354 go ahead
Subject: This is a test subject

 

This is just a test mail send through telnet
.
250 ok 1536440787 qp 28058
^]
telnet>

 

Note that the returned messages are native to qmail, a postfix would return a slightly different content, here is another test example to remote SMTP running sendmail or postfix.

 

root@pcfreak:~# telnet mail.servername.com 25
Trying 127.0.0.1…
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 mail.servername.com ESMTP Sendmail 8.13.8/8.13.8; Tue, 22 Oct 2013 05:05:59 -0400
HELO yahoo.com
250 mail.servername.com Hello mail.servername.com [127.0.0.1], pleased to meet you
mail from: systemexec@gmail.com
250 2.1.0 hipo@pc-freak.net… Sender ok
rcpt to: hip0d@yandex.ru
250 2.1.5 hip0d@yandex.ru… Recipient ok
data
354 Enter mail, end with "." on a line by itself
Hey
This is test email only

 

Thanks
.
250 2.0.0 r9M95xgc014513 Message accepted for delivery
quit
221 2.0.0 mail.servername.com closing connection
Connection closed by foreign host.


It is handy if you want to know whether remote MTA server has a certain Emailbox existing or not with telnet by simply trying to send to a certian email and checking the Email server returned output (note that the message returned depends on the remote MTA version and many qmails are configured to not give information on the initial SMTP handshake but returns instead a MAILER DAEMON failure error sent back to your sender address. Some MX servrers are still vulnerable to this attack yet, historically dreamhost.com. Below attack screenshot is made at the times before dreamhost.com fixed the brute force email issue.

Terminal-Verify-existing-Email-with-telnet

6. Using simple netcat TCP/IP Swiss Army Knife to test and send email in console

netcat-logo-a-swiff-army-knife-of-the-hacker-and-security-expert-logo
Other tool besides telnet of testing remote / local SMTP is netcat tool (for reading and writting data across TCP and UDP connections).

The way to do it is analogous but since netcat is not present on most Linux OSes by default you need to install it through the package manager first be it apt or yum etc.

# apt-get –yes install netcat


 

First lets create a new file test_email_content.txt using bash's echo cmd.
 

 

# echo 'EHLO hostname
MAIL FROM: hip0d@yandex.ru
RCPT TO:   solutions@pc-freak.net
DATA
From: A tester <hip0d@yandex.ru>
To:   <solutions@pc-freak.net>
Date: date
Subject: A test message from test hostname

 

Delete me, please
.
QUIT
' >>test_email_content.txt

 

# netcat -C localhost 25 < test_email_content.txt

 

220 This is Mail Pc-Freak.NET ESMTP
250-This is Mail Pc-Freak.NET
250-STARTTLS
250-SIZE 80000000
250-PIPELINING
250 8BITMIME
250 ok
250 ok
354 go ahead
451 See http://pobox.com/~djb/docs/smtplf.html.

Because of its simplicity and the fact it has a bit more capabilities in reading / writing data over network it was no surprise it was among the favorite tools not only of crackers and penetration testers but also a precious debug tool for the avarage sysadmin. netcat's advantage over telnet is you can push-pull over the remote SMTP port (25) a non-interactive input.


7. Using openssl to connect and send email via encrypted channel

 

root@linux:~# openssl s_client -connect smtp.gmail.com:465 -crlf -ign_eof

    ===
               Certificate negotiation output from openssl command goes here
        ===

        220 smtp.gmail.com ESMTP j92sm925556edd.81 – gsmtp
            EHLO localhost
        250-smtp.gmail.com at your service, [78.139.22.28]
        250-SIZE 35882577
        250-8BITMIME
        250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER XOAUTH
        250-ENHANCEDSTATUSCODES
        250-PIPELINING
        250-CHUNKING
        250 SMTPUTF8
            AUTH PLAIN *passwordhash*
        235 2.7.0 Accepted
            MAIL FROM: <hipo@pcfreak.org>
        250 2.1.0 OK j92sm925556edd.81 – gsmtp
            rcpt to: <systemexec@gmail.com>
        250 2.1.5 OK j92sm925556edd.81 – gsmtp
            DATA
        354  Go ahead j92sm925556edd.81 – gsmtp
            Subject: This is openssl mailing

            Hello nice user
            .
        250 2.0.0 OK 1339757532 m46sm11546481eeh.9
            quit
        221 2.0.0 closing connection m46sm11546481eeh.9
        read:errno=0


8. Using CURL (URL transfer) tool to send SSL / TLS secured crypted channel emails via Gmail / Yahoo servers and MailGun Mail send API service


Using curl webpage downloading advanced tool for managing email send might be  a shocking news to many as it is idea is to just transfer data from a server.
curl is mostly used in conjunction with PHP website scripts for the reason it has a Native PHP implementation and many PHP based websites widely use it for download / upload of user data.
Interestingly besides support for HTTP and FTP it has support for POP3 and SMTP email protocols as well
If you don't have it installed on your server and you want to give it a try, install it first with apt:
 

root@linux:~# apt-get install curl

 


To learn more about curl capabilities make sure you check cURL –manual arg.
 

root@linux:~# curl –manual

 

a) Sending Emails via Gmail and other Mail Public services

Curl is capable to send emails from terminal using Gmail and Yahoo Mail services, if you want to give that a try.

gmail-settings-google-allow-less-secure-apps-sign-in-to-google-screenshot

Go to myaccount.google.com URL and login from the web interface choose Sign in And Security choose Allow less Secure Apps to be -> ON and turn on access for less secure apps in Gmail. Though I have not tested it myself so far with Yahoo! Mail, I suppose it should have a similar security settings somewhere.

Here is how to use curl to send email via Gmail.

Gmail-password-Allow-less-secure-apps-ON-screenshot-howto-to-be-able-to-send-email-with-text-commands-with-encryption-and-outlook

 

 

root@linux:~# curl –url 'smtps://smtp.gmail.com:465' –ssl-reqd \
  –mail-from 'your_email@gmail.com' –mail-rcpt 'remote_recipient@mail.com' \
  –upload-file mail.txt –user 'your_email@gmail.com:your_accout_password'


b) Sending Emails using Mailgun.com (Transactional Email Service API for developers)

To use Mailgun to script sending automated emails go to Mailgun.com and create account and generate new API key.

Then use curl in a similar way like below example:

 

curl -sv –user 'api:key-7e55d003b…f79accd31a' \
    https://api.mailgun.net/v3/sandbox21a78f824…3eb160ebc79.mailgun.org/messages \
    -F from='Excited User <developer@yourcompany.com>' \
    -F to=sandbox21a78f824…3eb160ebc79.mailgun.org \
    -F to=user_acc@gmail.com \
    -F subject='Hello' \
    -F text='Testing Mailgun service!' \
   –form-string html='<h1>EDMdesigner Blog</h1><br /><cite>This tutorial helps me understand email sending from Linux console</cite>' \
    -F attachment=@logo_picture.jpg

 

The -F option that is heavy present in above command lets curl (Emulate a form filled in button in which user has pressed the submit button).
For more info of the options check out man curl.
 

 

9. Using swaks command to send emails from

 

root@linux:~# apt-cache show swaks|grep "Description" -B 10
Package: swaks
Version: 20170101.0-1
Installed-Size: 221
Maintainer: Andreas Metzler <ametzler@debian.org>
Architecture: all
Depends: perl
Recommends: libnet-dns-perl, libnet-ssleay-perl
Suggests: perl-doc, libauthen-sasl-perl, libauthen-ntlm-perl
Description-en: SMTP command-line test tool
 swaks (Swiss Army Knife SMTP) is a command-line tool written in Perl
 for testing SMTP setups; it supports STARTTLS and SMTP AUTH (PLAIN,
 LOGIN, CRAM-MD5, SPA, and DIGEST-MD5). swaks allows one to stop the
 SMTP dialog at any stage, e.g to check RCPT TO: without actually
 sending a mail.
 .
 If you are spending too much time iterating "telnet foo.example 25"
 swaks is for you.
Description-md5: f44c6c864f0f0cb3896aa932ce2bdaa8

 

 

 

root@linux:~# apt-get instal –yes swaks

root@linux:~# swaks –to mailbox@example.com -s smtp.gmail.com:587
      -tls -au <user-account> -ap <account-password>

 


The -tls argument (in order to use gmail encrypted TLS channel on port 587)

If you want to hide the password not to provide the password from command line so (in order not to log it to user history) add the -a options.

10. Using qmail-inject on Qmail mail servers to send simple emails

Create new file with content like:
 

root@qmail:~# vim email_file_content.text
To: user@mail-example.com
Subject: Test


This is a test message.
 

root@qmail:~# cat email_file_content.text | /var/qmail/bin/qmail-inject


qmail-inject is part of ordinary qmail installation so it is very simple it even doesn't return error codes it just ships what ever given as content to remote MTA.
If the linux host where you invoke it has a properly configured qmail installation the email will get immediately delivered. The advantage of qmail-inject over the other ones is it is really lightweight and will deliver the simple message more quickly than the the prior heavy tools but again it is more a Mail Delivery Agent (MDA) for quick debugging, if MTA is not working, than for daily email writting.

It is very useful to simply test whether email send works properly without sending any email content by (I used qmail-inject to test local email delivery works like so).
 

root@linux:~# echo 'To: mailbox_acc@mail-server.com' | /var/qmail/bin/qmail-inject

 

11. Debugging why Email send with text tool is not being send properly to remote recipient

If you use some of the above described methods and email is not delivered to remote recipient email addresses check /var/log/mail.log (for a general email log and postfix MTAs – the log is present on many of the Linux distributions) and /var/log/messages or /var/log/qmal (on Qmail installations) /var/log/exim4 (on servers running Exim as MTA).

http://pc-freak.net/images/linux-email-log-debug-var-log-mail-output

 Closure

The ways to send email via Linux terminal are properly innumerous as there are plenty of scripted tools in various programming languages, I am sure in this article,  also missing a lot of pre-bundled installable distro packages. If you know other interesting ways / tools to send via terminal I would like to hear it.

Hope you enjoyed, happy mailing !

Happy New Church Year ! – The Eastern Orthodox Church Year celebrated every 1st of September and some history on the Indiction

Wednesday, September 5th, 2018

Eastern_Orthodox-Church-new-year-indiction

Happy New Year, Happy New Church Year !  🙂

On first of September every year the Holy Eastern Orthodox Church to which I belong is celebrating the beginning of a new Church Calendar feast year.

It is a common practice here in Bulgaria (as we are one of the 14 Eastern Orthodox Churches worldwide) it is a tradition to serve holy liturgies across the country and prayers are lifted to heaven for the well being of the Bulgarian nation and the world.

In the past the beginning of the new year was called also the beginning of the indiction.
In the VI-th century at the time of Emperor Justinian The Great in Byzantine Empire was introduce the Cyclical Calendar based calculation of days (based on indictions ) – this is delivered from latin word indictio (meaning announcement).
Indictions
were celebrated originally on a cyclical periods of 15 years when the а financial review of the properties (possessions) of citizens  that were taxated.

In the Latin Empire the word indictio has been used to mark the exact amount of taxes owed each year and in this is how with the beginning of the new indiction was beginning the new financial year of the empire according to some historians the origin of indictions system has been originating from Egypt.

The official byzantine calculation of indictions begun at the time of Saint Emperor Constantine on 1st of September year 312 A.D.
Historically it is interesting fact both in the Western and in the Eastern Latin empire March was another time marking a New Year …

On 1st of September in the Church it is accepted to read the Bible chapter where Jesus Christ red in the synagogue the prophecy of Isaiah (Is. 61:1-2) for the occurance of the favorable year of God. The Byzantines see in that reading a reference of the Lord for a celebration of a New Year. 

In the Menologion of Basyl II from the 10th century it is said "From that time, he has granted to us the Christians this feast".

Primary_Chronicle_Povesti_Vremeninnih_let-baptizmal-of-Olga

It is interesting fact that in Byzantium this Bible reading was red in the Church by the Patriarch in Hagia Sophia Church Cathedral or another Church where it was common for him to serve Holy Liturgy on that date.

In Russia even though the Baptismal and Christianization of the nation until 15th century the Church New year begun on 1st of March. This is evident from all medieval manuscripts including The most famous and among most ancient Russian manuscript written by the eminent Nestor so called Primary Manuscript (Primary Chronicle) also called Tale of Begone Years.
 

With an Emperor decree of King Peter the I-st (The Great) the new year in Russia is transferred to 1st of January.

Saint_Simeon_Stylites-Stulpnik

Saint Simeon the Stylites

Our Bulgarian Orthodox Church by tradition according to the main Church service instructions book – the Typikon marks on the first day of the new year as a very important "tiny Lord feast" and has tradition to celebrate the memory of saint Simeon the Stylites who spend mostly all his life praying on a Stylite and was a notable ascet of the Orthodox Church.

 

Baby boomers and Generation X, Y, Z – Generational Marketing and 4 Common personality stereotype traits of people born over the last 60 years

Saturday, August 18th, 2018

baby-bommers-and-x-y-z-generations

Those who are employed in the realm of Social or Internet Marketing definitely have to know the existence of at least 4 different conditional stereotypes, these are Baby Boomers and Generation X, Generation Y and Generation Z (Millenials).

According to Socielogist Karl Mannheim (who is among the founding fathers of classical socielogy) – "All members of a generation share a similar collective experience" or in other words people are categorized in generations depending on when they were born.

As stereotypes they're generalization of people born in different periods of time and sharing same or similar traits.
Because of the age and the conditions they grew up and as they share those general spirit of time and age, they tend to be more or less behaving in a similar ways in how they think save / spend money or share some common approach to life choices and attitude towards life and worldview.

But before proceeding to the 4 main cohert provisional stereotypes, its worthy to mention how these four common trait generations came to existence with a little bit of pre-history.

The pre WW I and WW II world situation and the First and Second World War played a pivotal role in forming the social conditions necessery for the development of the baby boomers.

* The depression Era people

Born in period: 1912 – 1921 who came at full maturity around 1930-1939 right in the beginning of WW I (all of whom are already deceased) as of 2018 as a cause of the war uncertainty and the havoc and the war conditions were very conservative, compulsive savers, tried their best to maintain a low debt. They had the mindset (responsibility) to leave some kind of legacy to their children. They were very patriotic, oriented towards work before pleasure, had a great respect for authority and had a strong sense of moral obligation. For all this character traits of this people undoubtfully a key role played the strong belief in God mostly all people had at the time.

The next in line conditional stereotype of people that came to earth are the:

* The World War II Generation
 

Born in year period: 1922 to 1927 who came to a mature age exactly at the terrible years of Second World War.

People of that time were either fighters for or against the Axis Powers or the Central Powers with the common shared goal to fight against the enemy (of course there are multiple of people who were just trying to survive and not taking a side in this meaningless war).

The current amount of people living are estimated to few million of deathbed elders  worldwide.

As above conditional generations types mentioned are of importance for historical reasons and most of the people belonging to those depression pre WWI and WW II era are dead or just a few millions an overall in un less-consuming age (excluding the medicine consumption which is higher compared to youngsters).

I'll further proceed further with the Baby Boomers, GEN X, Y, Zs who are de-facto the still active members participating to society and economy more or less.

baby-boomers-generation-x-y-z-chart-table-by-year-of-birth

So what are these 4 Stereotypes of Generations that and why are so important for the modern marketers or business manager?

 

1. BABY BOOMERS also called for a short (Boomers)
 

we-are-who-are-baby-boomers

These are people who have been defined by a birth year range (period) from early to mid 1940s  until 1960 and 1964.

 In Europe and North America, boomers are widely identified with privilege, as many grew up in a time of widespread government subsidies in post-war housing and education, and increasing affluence.

As a group, baby boomers were considered the wealthiest, most active, and most physically fit generation up to the era in which they arrived, and were amongst the first to grow up genuinely expecting the world to improve with time. They were also the generation that received peak levels of income; they could therefore reap the benefits of abundant levels of food, apparel, retirement programs, and sometimes even "midlife crisis" products. The increased consumerism for this generation has been regularly criticized as excessive (and that's for a good reason).

One feature of the boomers was that they have tended to think of themselves as a special generation, very different from those that had come before or that has come afterward. In the 1960s, as the relatively large numbers of young people became teenagers and young adults, they, and those around them, created a very specific rhetoric around their cohort, and the changes they were bringing about. This rhetoric had an important impact in the self perceptions of the boomers, as well as their tendency to define the world in terms of generations, which was a relatively new phenomenon. The baby boom has been described variously as a "shockwave" and with a methapors such as as "the pig in the python".

 

2. Generation X / GEN X

generation-x-who-are-they-gen-x-explained-picture

Generation X is considered the people born in the following birth year period 1960 forward in time until 1980s. A specific feature in the 60s-80s period was the shifting societal values, perhaps the spring of this generation was also connected to the increasing role and spread of communism in the world.
Sometimes this generation was referred as the "latchkey generation".
The term generation X itself was popularized largely by Douglas Coupland in his novel 1991 novel Generation X Tales for an Accelerated Culture

A very common trait for Generation X was the reduced adult supervision over kids when compared to previous generations a result of increasing divorce rates and the increased role of one parent children upbringing (in most cases that was the mother) which had to be actively involved as a workforce and lacked physically the time to spend enough time with its children and the increased use of childcare options in one parent families.

They were dubbed the "MTV" (Music Television) generation – that was a hit and most popular music TV in the early 1990s.
The kids representing generation X were described as slackers, cynical and disaffected.

The cultural influences dominating the tastes and feelings of the teen masses of that generation was musical genres such as punk music, heavy metal music, grunge and hip-hop and indie films (independent films)  produced outside of the major film studio system.

According to many researches in midtime those generation are described as active, happy and achieving a work-life balance kind of lifestyle.

People belonging to Generation X are described as people with Enterpreneural tendencies.

Just to name a few of the celebrities and successful people who belong to this generation, that's Google's founder Sergey Brinn & Larry Page (born in 1973), Richard Stallman (founder of Free Software movement) as well movie and film producer celebrities such as Georgi Clooney, Lenny Kravitz, Quantin Tarantino, Kevin Smith, David Fincher etc.

According to United Kingdom survey study of 2500+ workers conducted by Workfront, GEN X are found to be among the hardest working employees in today's workforce. They are also ranked high by fellow workers for having a strong work ethics (about 59.5%), being helpful (55.4%) and very skilled (54.5%) of respondents as well marked as the best troubleshooters / problem solvers (41.6%) claimed so.
According to research conducted by Viacom, gen x they have a high desire for flexibility and fulfillment at work.

3. Generation Y (Millenials) – GEN Y
 

who-are-generation-y-millenials-explained

Following Generation X came on earth Genreation Y the birth period dated for this kids were years are stretchy year period that this generation is described are years 1980s – 1990s to yearly 2000s where birth period range of those ppl ends.
This kids are descendants of the GEN X and second wave Baby Boomers.
In the public this generation is referred as "echo boomers".

The Millenials characteristics are different based on the region of birth, they're famous for the increased familiarity with communication, media and digital technologies.

millenials-focus-on-technology-innovation-and-their-technological-preferences

There upbringing was marked by increase in liberal approach to politics.
The Great recession crisis of the 2000s played a major impact on this generation because it has caused historical high levels of un-employment among youngsters and led to a possible long term economic and social damage to this generation.

millennials-are-heavily-influenced-by-their-peers
Gen Y according are less brand loyal and the speed of the Internet has led the cohort to be similarly flexible and changing in its fashion, style consciousness and where
and how it is communicated with.

As I am born in 1983 me and my generation belongs to Generation Y and even though Bulgaria before 1991 was a Communist regime country, I should agree that I and many of my friends share a very similar behavior and way of thinking to the GEN Y stereotype described, but as I was born in a times of transition and Bulgaria as a Soviet Union Satellite at the time has been lacking behind in fashion and international culture due to the communist regime, me and my generation seem to be sharing a lot of common stereotype characteristics with Generation X such as the punk-rock, metal, hip-hop culture MTV culture and partly because of the GEN X like overall view on life.

Among most famous representative successful people of the Millenials generation are Mark Zuckerberg (Facebook founder), Prince William (the second in line to the British throne), Kim Jong Un (the leader dictator of North Korea) etc.
 

 

4. Generation Z ( GEN Z) / iGeneration / Generation Sensible (Post Millenials)
 

who-are-generation-y-millenials-explained

Following Millenials generation is GEN Z, demographers and researchers typically set as a starting birth date period of those generation 1990s and mid 2000s. As of time of writting there is still no clear consensus regarding ending birth years.

This is the so called Internet Generation because this generation used the internet and Smart Mobile Phone technology since a very young age, they are very confortable with technology (kinda of wired) and addicted to social media such as Facebook / Twitter / Instagram etc. Because of the level of digital communication, many people of this generation are more introvert oriented and often have problems expressing themselves freely in groups. Also they tend to lack the physical communication and more digitally community oriented, even though this depends much also on the specific personality and in some cases it is exactly the opposite.

 

 * Summary
 

As a Marketer, Human Resources hiring personal specialist, a CEO or some kind of project / business manager it is a good idea to be aware of these 4 common stereotypes. However as this are stereotypes (and a theory) as everything theoritized the data is slighly biased and untrue. The marketer practice shows that whoever conducts a marketing and bases his sales on this theoritizing should consider this to be just one aspect of the marketing campaign those who are trying to sell, stuff ideas or ideology to any of those generation should be careful not to count 100% on the common traits found among the above 4 major groups and consider the individuality of person everyone has and just experiment a little bit to see what works and what doesn't.

Also it should be mentioned these diversification of stereotypes are mostly valid for the US citizens and Westerners but doesn't fully fit to ex-communist countries or countries of the Soviet union, those countries have a slightly different personality traits of person born in any of the year periods defined, same is more or less true for the poor parts of Africa and India, Vietnam, China and mostly all of the coomunist countries ex and current. It should be said that countries who belonged to the Soviet Union many of which are current Russian Federation Republics have a personality traits that are often mixture of the 4 stereotypes and even have a lot of the traits that were typical for the WW I and WW II generations, which makes dealing with this people a very weird experience.

Nomatter the standard error that should always considered when basing a marketing research hypothesis on Generational Marketing (using generational segmentation in marketing best potential customer targets), having a general insight and taking in consideration those stereotypes could seriously help in both marketing as well as HR specific fields like Change Management.

generation-x-y-z-characteristics

If you're a marketer, I recommend you take a quick look also on following very educative article Generational Makarketing and how to target each of the GEN X, Y, Z and Baby Boomers and what works best for each of them.

Nomatter what just like all Theories, the theory of Boomers and the Generation segmantation is not completely true, but it gives a good soil for reasoning as well definitely helps for people involved in sociology and business.

Comments and feedback on the article are mostly welcome as the topic is very broad and there is much more to be said …

Hope the article was interesting to you ….

What was your Generation like?

Virtual Keyboard for Linux and other Freedom respecting operating Systems

Monday, July 30th, 2018

How to install and Use Linux Virtual Keyboard and other freedom respecting Operating Systems

  •  Looking for a quick way to use VIRTUAL KEYBOARD ON LINUX COMPUTER OPERATING SYSTEM, you can do it just this 1 task in 3 simple steps  ???
    – Logical question emerges, WHY ??? would you need a virtual keyboard on Free Software OS such as Linux?
    Well, just because sometimes it is much more secure to use a Virtual Keyboard, especially if you have doubt that your keyboard has been tapped or a Key Logger (Sniffer), intercepting the Keyboard IN / OUT jacks, is installed on the computer or you might have sit on a computer of ,a friend running Linux, and you want to make sure he did not install sniffer to intercept your ,SSH login passwords and ,later hack into your Servers, after stealing, the password

 

  • Assuming you're on : – Debian / Ubuntu Linux, or other of the numerous IT systems such as ,FreeBSD / OpeBSD etc. out there, you can run simply this commands:

     

  •  apt-get install –yes florence
    * A. To make it, easily invokable for laters, create a small bash, shell script in directory; – location /usr/bin/virtual-keyboard like, the one below:

    vim /usr/bin/virtual-keyboard

    * B.. INside the file Place following 1 liner code
     

    #!/bin/sh
    /usr/bin/florence

     

    * C… To later invoke it any time:
    Press ALT + F2 (or use Run Command Dialog in GNOME / KDE / Windomaker / IceWM whatever or any other crazy graphic environment of your choice and run:

    /usr/bin/virtual-keyboard