Posts Tagged ‘cfg’

How to automate open xen Hypervisor Virtual Machines backups shell script

Tuesday, June 22nd, 2021

openxen-backup-logo As a sysadmin that have my own Open Xen Debian Hypervisor running on a Lenovo ThinkServer few months ago due to a human error I managed to mess up one of my virtual machines and rebuild the Operating System from scratch and restore files service and MySQl data from backup that really pissed me of and this brought the need for having a decent Virtual Machine OpenXen backup solution I can implement on the Debian ( Buster) 10.10 running the free community Open Xen version 4.11.4+107-gef32c7afa2-1. The Hypervisor is a relative small one holding just 7 VM s:

HypervisorHost:~#  xl list
Name                                        ID   Mem VCPUs      State   Time(s)
Domain-0                                     0 11102    24     r—–  214176.4
pcfrxenweb                                  11 12288     4     -b—-  247425.5
pcfrxen                                     12 16384    10     -b—-  1371621.4
windows7                                    20  4096     2     -b—-   97887.2
haproxy2                                    21  4096     2     -b—-   11806.9
jitsi-meet                                  22  2048     2     -b—-   12843.9
zabbix                                      23  2048     2     -b—-   20275.1
centos7                                     24  2040     2     -b—-   10898.2

HypervisorHost:~# xl list|grep -v 'Name ' |grep  -v 'Domain-0'  |wc -l
7


The backup strategy of the script is very simple to shutdown the running VM machine, make a copy with rsync to a backup location the image of each of the Virtual Machines in a bash shell loop for each virtual machine shown in output of xl command and backup to a preset local directory in my case this is /backups/ the backup of each virtual machine is produced within a separate backup directory with a respective timestamp. Backup VM .img files are produced in my case to mounted 2x external attached hard drives each of which is a 4 Terabyte Seagate Plus Backup (Storage). The original version of the script was made to be a slightly different by Zhiqiang Ma whose script I used for a template to come up with my xen VM backup solution. To prevent the Hypervisor's load the script is made to do it with a nice of (nice -n 10) this might be not required or you might want to modify it to better suit your needs. Below is the script itself you can fetch a copy of it /usr/sbin/xen_vm_backups.sh :

#!/bin/bash

# Author: Zhiqiang Ma (http://www.ericzma.com/)
# Modified to work with xl and OpenXen by Georgi Georgiev – https://pc-freak.net
# Original creation dateDec. 27, 2010
# Script takes all defined vms under xen_name_list and prepares backup of each
# after shutting down the machine prepares archive and copies archive in externally attached mounted /backup/disk1 HDD
# Latest update: 08.06.2021 G. Georgiev – hipo@pc-freak.net

mark_file=/backups/disk1/tmp/xen-bak-marker
log_file=/var/log/xen/backups/bak-$(date +%Y_%m_%d).log
err_log_file=/var/log/xen/backups/bak_err-$(date +%H_%M_%Y_%m_%d).log
xen_dir=/xen/domains
xen_vmconfig_dir=/etc/xen/
local_bak_dir=/backups/disk1/tmp
#bak_dir=xenbak@backup_host1:/lhome/xenbak
bak_dir=/backups/disk1/xen-backups/xen_images/$(date +%Y_%m_%d)/xen/domains
#xen_name_list="haproxy2 pcfrxenweb jitsi-meet zabbix windows7 centos7 pcfrxenweb pcfrxen"
xen_name_list="windows7 haproxy2 jitsi-meet zabbix centos7"

if [ ! -d /var/log/xen/backups ]; then
echo mkdir -p /var/log/xen/backups
 mkdir -p /var/log/xen/backups
fi

if [ ! -d $bak_dir ]; then
echo mkdir -p $bak_dir
 mkdir -p $bak_dir

fi


# check whether bak runned last week
if [ -e $mark_file ] ; then
        echo  rm -f $mark_file
 rm -f $mark_file
else
        echo  touch $mark_file
 touch $mark_file
  # exit 0
fi

# set std and stderr to log file
        echo mv $log_file $log_file.old
       mv $log_file $log_file.old
        echo mv $err_log_file $err_log_file.old
       mv $err_log_file $err_log_file.old
        echo "exec 2> $err_log_file"
       exec 2> $err_log_file
        echo "exec > $log_file"
       exec > $log_file


# check whether the VM is running
# We only backup running VMs

echo "*** Check alive VMs"

xen_name_list_tmp=""

for i in $xen_name_list
do
        echo "/usr/sbin/xl list > /tmp/tmp-xen-list"
        /usr/sbin/xl list > /tmp/tmp-xen-list
  grepinlist=`grep $i" " /tmp/tmp-xen-list`;
  if [[ “$grepinlist” == “” ]]
  then
    echo $i is not alive.
  else
    echo $i is alive.
    xen_name_list_tmp=$xen_name_list_tmp" "$i
  fi
done

xen_name_list=$xen_name_list_tmp

echo "Alive VM list:"

for i in $xen_name_list
do
   echo $i
done

echo "End alive VM list."

###############################
date
echo "*** Backup starts"

###############################
date
echo "*** Copy VMs to local disk"

for i in $xen_name_list
do
  date
  echo "Shutdown $i"
        echo  /usr/sbin/xl shutdown $i
        /usr/sbin/xl shutdown $i
        if [ $? != ‘0’ ]; then
                echo 'Not Xen Disk image destroying …';
                /usr/sbin/xl destroy $i
        fi
  sleep 30

  echo "Copy $i"
  echo "Copy to local_bak_dir: $local_bak_dir"
      echo /usr/bin/rsync -avhW –no-compress –progress $xen_dir/$i/{disk.img,swap.img} $local_bak_dir/$i/
     time /usr/bin/rsync -avhW –no-compress –progress $xen_dir/$i/{disk.img,swap.img} $local_bak_dir/$i/
      echo /usr/bin/rsync -avhW –no-compress –progress $xen_vmconfig_dir/$i.cfg $local_bak_dir/$i.cfg
     time /usr/bin/rsync -avhW –no-compress –progress $xen_vmconfig_dir/$i.cfg $local_bak_dir/$i.cfg
  date
  echo "Create $i"
  # with vmmem=1024"
  # /usr/sbin/xm create $xen_dir/vm.run vmid=$i vmmem=1024
          echo /usr/sbin/xl create $xen_vmconfig_dir/$i.cfg
          /usr/sbin/xl create $xen_vmconfig_dir/$i.cfg
## Uncomment if you need to copy with scp somewhere
###       echo scp $log_file $bak_dir/xen-bak-111.log
###      echo  /usr/bin/rsync -avhW –no-compress –progress $log_file $local_bak_dir/xen-bak-111.log
done

####################
date
echo "*** Compress local bak vmdisks"

for i in $xen_name_list
do
  date
  echo "Compress $i"
      echo tar -z -cfv $bak_dir/$i-$(date +%Y_%m_%d).tar.gz $local_bak_dir/$i-$(date +%Y_%m_%d) $local_bak_dir/$i.cfg
     time nice -n 10 tar -z -cvf $bak_dir/$i-$(date +%Y_%m_%d).tar.gz $local_bak_dir/$i/ $local_bak_dir/$i.cfg
    echo rm -vf $local_bak_dir/$i/ $local_bak_dir/$i.cfg
    rm -vrf $local_bak_dir/$i/{disk.img,swap.img}  $local_bak_dir/$i.cfg
done

####################
date
echo "*** Copy local bak vmdisks to remote machines"

copy_remote () {
for i in $xen_name_list
do
  date
  echo "Copy to remote: vm$i"
        echo  scp $local_bak_dir/vmdisk0-$i.tar.gz $bak_dir/vmdisk0-$i.tar.gz
done

#####################
date
echo "Backup finishes"
        echo scp $log_file $bak_dir/bak-111.log

}

date
echo "Backup finished"

 

Things to configure before start using using the script to prepare backups for you is the xen_name_list variable

#  directory skele where to store already prepared backups
bak_dir=/backups/disk1/xen-backups/xen_images/$(date +%Y_%m_%d)/xen/domains

# The configurations of the running Xen Virtual Machines
xen_vmconfig_dir=/etc/xen/
# a local directory that will be used for backup creation ( I prefer this directory to be on the backup storage location )
local_bak_dir=/backups/disk1/tmp
#bak_dir=xenbak@backup_host1:/lhome/xenbak
# the structure on the backup location where daily .img backups with be produced with rsync and tar archived with bzip2
bak_dir=/backups/disk1/xen-backups/xen_images/$(date +%Y_%m_%d)/xen/domains

# list here all the Virtual Machines you want the script to create backups of
xen_name_list="windows7 haproxy2 jitsi-meet zabbix centos7"

If you need the script to copy the backup of Virtual Machine images to external Backup server via Local Lan or to a remote Internet located encrypted connection with a passwordless ssh authentication (once you have prepared the Machines to automatically login without pass over ssh with specific user), you can uncomment the script commented section to adapt it to copy to remote host.

Once you have placed at place /usr/sbin/xen_vm_backups.sh use a cronjob to prepare backups on a regular basis, for example I use the following cron to produce a working copy of the Virtual Machine backups everyday.
 

# crontab -u root -l 

# create windows7 haproxy2 jitsi-meet centos7 zabbix VMs backup once a month
00 06 1,2,3,4,5,6,7,8,9,10,11,12 * * /usr/sbin/xen_vm_backups.sh 2>&1 >/dev/null


I do clean up virtual machines Images that are older than 95 days with another cron job

# crontab -u root -l

# Delete xen image files older than 95 days to clear up space from backup HDD
45 06 17 * * find /backups/disk1/xen-backups/xen_images* -type f -mtime +95 -exec rm {} \; 2>&1 >/dev/null

#### Delete xen config backups older than 1 year+3 days (368 days)
45 06 17 * * find /backups/disk1/xen-backups/xen_config* -type f -mtime +368 -exec rm {} \; 2>&1 >/dev/null

 

# Delete xen image files older than 95 days to clear up space from backup HDD
45 06 17 * * find /backups/disk1/xen-backups/xen_images* -type f -mtime +95 -exec rm {} \; 2>&1 >/dev/null

#### Delete xen config backups older than 1 year+3 days (368 days)
45 06 17 * * find /backups/disk1/xen-backups/xen_config* -type f -mtime +368 -exec rm {} \; 2>&1 >/dev/null

KVM Virtual Machine RHEL 8.3 Linux install on Redhat 8.3 Linux Hypervisor with custom tailored kickstart.cfg

Friday, January 22nd, 2021

kvm_virtualization-logo-redhat-8.3-install-howto-with-kickstart

If you don't have tried it yet Redhat and CentOS and other RPM based Linux operationg systems that use anaconda installer is generating a kickstart file after being installed under /root/{anaconda-ks.cfg,initial-setup- ks.cfg,original-ks.cfg} immediately after the OS installation completes. Using this Kickstart file template you can automate installation of Redhat installation with exactly the same configuration as many times as you like by directly loading your /root/original-ks.cfg file in RHEL installer.

Here is the official description of Kickstart files from Redhat:

"The Red Hat Enterprise Linux installation process automatically writes a Kickstart file that contains the settings for the installed system. This file is always saved as /root/anaconda-ks.cfg. You may use this file to repeat the installation with identical settings, or modify copies to specify settings for other systems."


Kickstart files contain answers to all questions normally asked by the text / graphical installation program, such as what time zone you want the system to use, how the drives should be partitioned, or which packages should be installed. Providing a prepared Kickstart file when the installation begins therefore allows you to perform the installation automatically, without need for any intervention from the user. This is especially useful when deploying Redhat based distro (RHEL / CentOS / Fedora …) on a large number of systems at once and in general pretty useful if you're into the field of so called "DevOps" system administration and you need to provision a certain set of OS to a multitude of physical servers or create or recreate easily virtual machines with a certain set of configuration.
 

1. Create /vmprivate storage directory where Virtual machines will reside

First step on the Hypervisor host which will hold the future created virtual machines is to create location where it will be created:

[root@redhat ~]#  lvcreate –size 140G –name vmprivate vg00
[root@redhat ~]#  mkfs.ext4 -j -b 4096 /dev/mapper/vg00-vmprivate
[root@redhat ~]# mount /dev/mapper/vg00-vmprivate /vmprivate

To view what is the situation with Logical Volumes and  VG group names:

[root@redhat ~]# vgdisplay -v|grep -i vmprivate -A7 -B7
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  – currently set to     8192
  Block device           253:0

 

  — Logical volume —
  LV Path                /dev/vg00/vmprivate
  LV Name                vmprivate
  VG Name                vg00
  LV UUID                VVUgsf-FXq2-TsMJ-QPLw-7lGb-Dq5m-3J9XJJ
  LV Write Access        read/write
  LV Creation host, time lpgblu01f.ffm.de.int.atosorigin.com, 2021-01-20 17:26:11 +0100
  LV Status              available
  # open                 1
  LV Size                150.00 GiB


Note that you'll need to have the size physically available on a SAS / SSD Hard Drive physically connected to Hypervisor Host.

To make the changes Virtual Machines storage location directory permanently mounted add to /etc/fstab

/dev/mapper/vg00-vmprivate  /vmprivate              ext4    defaults,nodev,nosuid 1 2

[root@redhat ~]# echo '/dev/mapper/vg00-vmprivate  /vmprivate              ext4    defaults,nodev,nosuid 1 2' >> /etc/fstab

 

2. Second we need to install the following set of RPM packages on the Hypervisor Hardware host

[root@redhat ~]# yum install qemu-kvm qemu-img libvirt virt-install libvirt-client virt-manager libguestfs-tools virt-install virt-top -y

3. Enable libvirtd on the host

[root@redhat ~]#  lsmod | grep -i kvm
[root@redhat ~]#  systemctl enable libvirtd

4. Configure network bridging br0 interface on Hypervisor


In /etc/sysconfig/network-scripts/ifcfg-eth0 you need to include:

NM_CONTROLED=NO

Next use nmcli redhat configurator to create the bridge (you can use ip command instead) but since the tool is the redhat way to do it lets do it their way ..

[root@redhat ~]# nmcli connection delete eno3
[root@redhat ~]# nmcli connection add type bridge autoconnect yes con-name br0 ifname br0
[root@redhat ~]# nmcli connection modify br0 ipv4.addresses 10.80.51.16/26 ipv4.method manual
[root@redhat ~]# nmcli connection modify br0 ipv4.gateway 10.80.51.1
[root@redhat ~]# nmcli connection modify br0 ipv4.dns 172.20.88.2
[root@redhat ~]# nmcli connection add type bridge-slave autoconnect yes con-name eno3 ifname eno3 master br0
[root@redhat ~]# nmcli connection up br0

5. Prepare a working kickstart.cfg file for VM


Below is a sample kickstart file I've used to build a working fully functional Virtual Machine with Red Hat Enterprise Linux 8.3 (Ootpa) .

#version=RHEL8
#install
# Run the Setup Agent on first boot
firstboot --enable
ignoredisk --only-use=vda

# Use network installation
#url --url=http://hostname.com/rhel/8/BaseOS
##url --url=http://171.23.8.65/rhel/8/os/BaseOS

# Use text mode install
text
#graphical

# System language
#lang en_US.UTF-8
keyboard --vckeymap=us --xlayouts='us'
# Keyboard layouts
##keyboard us
lang en_US.UTF-8

# Root password
rootpw $6$gTiUCif4$YdKxeewgwYCLS4uRc/XOeKSitvDJNHFycxWVHi.RYGkgKctTMCAiY2TErua5Yh7flw2lUijooOClQQhlbstZ81 --iscrypted

# network-stuff
# place ip=your_VM_IP, netmask, gateway, nameserver hostname 
network --bootproto=static --ip=10.80.21.19 --netmask=255.255.255.192 --gateway=10.80.21.1 --nameserver=172.30.85.2 --device=eth0 --noipv6 --hostname=FQDN.VMhost.com --onboot=yes
# if you need just localhost initially configured uncomment and comment above
##network В --device=lo --hostname=localhost.localdomain

# System authorization information
authconfig --enableshadow --passalgo=sha512 --enablefingerprint

# skipx
skipx

# Firewall configuration
firewall --disabled

# System timezone
timezone Europe/Berlin

# Clear the Master Boot Record
##zerombr

# Repositories
## Add RPM repositories from KS file if necessery
#repo --name=appstream --baseurl=http://hostname.com/rhel/8/AppStream
#repo --name=baseos --baseurl=http://hostname.com/rhel/8/BaseOS
#repo --name=inst.stage2 --baseurl=http://hostname.com ff=/dev/vg0/vmprivate
##repo --name=rhsm-baseos В  В --baseurl=http://172.54.8.65/rhel/8/rhsm/x86_64/BaseOS/
##repo --name=rhsm-appstream --baseurl=http://172.54.8.65/rhel/8/rhsm/x86_64/AppStream/
##repo --name=os-baseos В  В  В --baseurl=http://172.54.9.65/rhel/8/os/BaseOS/
##repo --name=os-appstream В  --baseurl=http://172.54.8.65/rhel/8/os/AppStream/
#repo --name=inst.stage2 --baseurl=http://172.54.8.65/rhel/8/BaseOS

# Disk partitioning information set proper disk sizing
##bootloader --location=mbr --boot-drive=vda
bootloader --append=" crashkernel=auto tsc=reliable divider=10 plymouth.enable=0 console=ttyS0 " --location=mbr --boot-drive=vda
# partition plan
zerombr
clearpart --all --drives=vda --initlabel
part /boot --size=1024 --fstype=ext4 --asprimary
part swap --size=1024
part pv.01 --size=30000 --grow --ondisk=vda
##part pv.0 --size=80000 --fstype=lvmpv
#part pv.0 --size=61440 --fstype=lvmpv
volgroup s pv.01
logvol / --vgname=s --size=15360 --name=root --fstype=ext4
logvol /var/cache/ --vgname=s --size=5120 --name=cache --fstype=ext4 --fsoptions="defaults,nodev,nosuid"
logvol /var/log --vgname=s --size=7680 --name=log --fstype=ext4 --fsoptions="defaults,nodev,noexec,nosuid"
logvol /tmp --vgname=s --size=5120 --name=tmp --fstype=ext4 --fsoptions="defaults,nodev,nosuid"
logvol /home --vgname=s --size=5120 --name=home --fstype=ext4 --fsoptions="defaults,nodev,nosuid"
logvol /opt --vgname=s --size=2048 --name=opt --fstype=ext4 --fsoptions="defaults,nodev,nosuid"
logvol /var/log/audit --vgname=s --size=3072 --name=audit --fstype=ext4 --fsoptions="defaults,nodev,nosuid"
logvol /var/spool --vgname=s --size=2048 --name=spool --fstype=ext4 --fsoptions="defaults,nodev,nosuid"
logvol /var --vgname=s --size=7680 --name=var --fstype=ext4 --fsoptions="defaults,nodev,nosuid"

# SELinux configuration
selinux --disabled
# Installation logging level
logging --level=debug

# reboot automatically
reboot

###

%packages
@standard
python3
pam_ssh_agent_auth
-nmap-ncat
#-plymouth
#-bpftool
-cockpit
#-cryptsetup
-usbutils
#-kmod-kvdo
#-ledmon
#-libstoragemgmt
#-lvm2
#-mdadm
-rsync
#-smartmontools
-sos
-subscription-manager-cockpit
# Tune Linux vm.dirty_background_bytes (IMAGE-439)
# The following tuning causes dirty data to begin to be background flushed at
# 100 Mbytes, so that it writes earlier and more often to avoid a large build
# up and improving overall throughput.
echo "vm.dirty_background_bytes=100000000" >> /etc/sysctl.conf

# Disable kdump
systemctl disable kdump.service
%end

Important note to make here is the MD5 set root password string in (rootpw) line this string can be generated with openssl or mkpasswd commands :

Method 1: use openssl cmd to generate (md5, sha256, sha512) encrypted pass string

[root@redhat ~]# openssl passwd -6 -salt xyz test
$6$xyz$rjarwc/BNZWcH6B31aAXWo1942.i7rCX5AT/oxALL5gCznYVGKh6nycQVZiHDVbnbu0BsQyPfBgqYveKcCgOE0

Note: passing -1 will generate an MD5 password, -5 a SHA256 encryption and -6 SHA512 encrypted string (logically recommended for better security)

Method 2: (md5, sha256, sha512)

[root@redhat ~]# mkpasswd –method=SHA-512 –stdin

The option –method accepts md5, sha-256 and sha-512
Theoretically there is also a kickstart file generator web interface on Redhat's site here however I never used it myself but instead use above kickstart.cfg
 

6. Install the new VM with virt-install cmd


Roll the new preconfigured VM based on above ks template file use some kind of one liner command line  like below:
 

[root@redhat ~]# virt-install -n RHEL8_3-VirtualMachine –description "CentOS 8.3 Virtual Machine" –os-type=Linux –os-variant=rhel8.3 –ram=8192 –vcpus=8 –location=/vmprivate/rhel-server-8.3-x86_64-dvd.iso –disk path=/vmprivate/RHEL8_3-VirtualMachine.img,bus=virtio,size=70 –graphics none –initrd-inject=/root/kickstart.cfg –extra-args "console=ttyS0 ks=file:/kickstart.cfg"

7. Use a tiny shell script to automate VM creation


For some clarity and better automation in case you plan to repeat VM creation you can prepare a tiny bash shell script:
 

#!/bin/sh
KS_FILE='kickstart.cfg';
VM_NAME='RHEL8_3-VirtualMachine';
VM_DESCR='CentOS 8.3 Virtual Machine';
RAM='8192';
CPUS='8';
# size is in Gigabytes
VM_IMG_SIZE='140';
ISO_LOCATION='/vmprivate/rhel-server-8.3-x86_64-dvd.iso';
VM_IMG_FILE_LOC='/vmprivate/RHEL8_3-VirtualMachine.img';

virt-install -n "$VMNAME" –description "$VM_DESCR" –os-type=Linux –os-variant=rhel8.3 –ram=8192 –vcpus=8 –location="$ISO_LOCATION" –disk path=$VM_IMG_FILE,bus=virtio,size=$IMG_VM_SIZE –graphics none –initrd-inject=/root/$KS_FILE –extra-args "console=ttyS0 ks=file:/$KS_FILE"


A copy of virt-install.sh script can be downloaded here

Wait for the installation to finish it should be visualized and if all installation is smooth you should get a login prompt use the password generated with openssl tool and test to login, then disconnect from the machine by pressing CTRL + ] and try to login via TTY with

[root@redhat ~]# virst list –all
 Id   Name        State
—————————
 2    
RHEL8_3-VirtualMachine   running

[root@redhat ~]#  virsh console RHEL8_3-VirtualMachine


redhat8-login-prompt

One last thing I recommend you check the official documentation on Kickstart2 from CentOS official website

In case if you later need to destroy the VM and the respective created Image file you can do it with:
 

[root@redhat ~]#  virsh destroy RHEL8_3-VirtualMachine
[root@redhat ~]#  virsh undefine RHEL8_3-VirtualMachine

Don't forget to celebreate the success and give this nice article a credit by sharing this nice tutorial with a friend or by placing a link to it from your blog 🙂

 

 

Enjoy !

Updating Flash Player on Debian GNU / Linux / Keeping Flash player up-to-date with update-flashplugin-nonfree

Saturday, November 10th, 2012

 

Update flash player on Debian GNU / Linux update-flashplugin-nonfree macromedia flash logo

Assuming you have previously installed and running Adobe Flash Player – package flashplugin-nonfree i.e.:

debian:~# dpkg -l |grep -i flashplugin-nonfree
ii flashplugin-nonfree 1:2.8.3 Adobe Flash Player - browser plugin

and you want to Update flash player to the latest provided version for Linux, there is an update script part of flashplugin-nonfree, package /usr/sbin/update-flashplugin-nonfree. The script updates flash player to latest Linux version avaiable fetching the version from macromedia's website in a .tar.gz and untarring it substituting the old flash library.

To update your Debian FlashPlayer, launch as superuser:

debian:~# update-flashplugin-nonfree --install
--2012-11-10 00:51:48-- http://fpdownload.macromedia.com/get/flashplayer/pdc/11.2.202.251/install_flash_player_11_linux_x86_64.tar.gz Resolving fpdownload.macromedia.com... 92.123.98.70 Connecting to fpdownload.macromedia.com|92.123.98.70|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 7228964 (6.9M) [application/x-gzip] Saving to: “./install_flash_player_11_linux_x86_64.tar.gz”

0K .......... .......... .......... ..........
.......... 0% 69.5K 1m41s 50K .......... .......... .......... ..........
.......... 1% 91.1K 88s 100K .......... .......... .......... ..........
.......... 2% 70.8K 91s ........
..........

After a while (usually up to a minute), update will be completed. Restart your browser of use IceWeasel, Epiphany, Opera, Chrome etc. and test it with About Flash Player Page and / or youtube. You should be with latest Flash Linux version now.

It might be a good idea to automate future flash player updates via a cron job, I think launching the update script every two weeks is a good timing;

To do so add to root user cron like so:

10,27 * * * * /usr/sbin/update-flashplugin-nonfree –install -q 2>&1 >/dev/null

If you still haven't configured your pulseaudio to play multiple sound streams do that too.

I've seen also on Debian's Wiki FlashPlayer page, mentioning that on some systems after update to Flash Player 11 there might be laggy performance issues, due to disabled hardware acceleration in Flash Player > v. 10. If that's the case with you you might also need to put a mss.cfg like this one to /etc/adobe/mss.cfg

# wget -q https://www.pc-freak.net/files/adobe-flash-player-config-for-hardware-acceleration-mms.cfg
# mv adobe-flash-player-config-for-hardware-acceleration-mms.cfg /etc/adobe/mms.cfg

Finally if you experience, some flash video lagging issues, you could try experimenting with OverrideGPUValidation=true flash setting which in some cases improves Linux flash video performance

Firefox users might be also interested to check out www.mozilla.org/en-US/plugincheck – the URL provides information on essential Firefox video plugins and whether plugins installed are up2date or prone to remote web exploitation vulnerability.

How to permanently enable Cookies in Lynx text browser – Disable accept cookies prompt in lynx console browser

Wednesday, April 18th, 2012

lynx-text-browser-logo
The default behaviour of lynx console text browser on Linuces, BSD and other free OSes is to always ask, for the accept cookies prompt once an internet web page is opened that requires browser cookies to be enabled.

I should admin, having this "secure by default" (always ask for new cookies) behaviour in lynx was a good practice from a security point of view.

Another reason, why this cookies prompt is enabled by default is back in the days, when lynx was actively developed by programmers the websites with cookies support was not that many and even cookies was mostly required for user/pass authentication (all those who still remember this days the websites that requires authentication was a way less than today) …
With this said the current continuing security cautious behaviour in the browser, left from its old days is understandable.

Screenshot Google Accept cookies Lynx dialog FreeBSD

However I personally sometimes, need to use lynx more frequently and this behaviour of always opening a new website in text mode in console to prompts me for a cookie suddenly becomes a big waste of time if you use lynx to browser more than few sites. Hence I decided to change the default way lynx handles cookies and make them enabled by default instead.
Actually even in the past, when I was mainly using internet in console on every new server or home Linux install, I was again making the cookies to be permanently accepted.
Everyone who used lynx a few times already knows its "annoying" to all time accept cookie prompts … This provoked me to write this short article to explain how enabling of constant cookie accepting in lynx is done

To enable the persistent cookies in lynx, one needs to edit lynx.cfg on different GNU / Linux and BSD* distributions lynx.cfg is located in different directory.

Most of the lynx.cfg usual locations are /etc/lynx/lynx.cfg or /etc/lynx.cfg as of time of writting this post in Debian Squeeze GNU / Linux the lynx.cfg is located in /etc/lynx-cur/lynx.cfg, whether for FreeBSD / NetBSD / OpenBSD users the file is located in /usr/local/etc/lynx.cfg

What I did to allow all cookies is open lynx.cfg in vim edit and change the following lines:

a)

#FORCE_SSL_COOKIES_SECURE:FALSE

with

FORCE_SSL_COOKIES_SECURE:TRUE

b)

#SET_COOKIES:TRUE

uncomment it to:

SET_COOKIES:TRUE

c) next, change

ACCEPT_ALL_COOKIES:FALSE

ACCEPT_ALL_COOKIES:TRUE

Onwards opening any website with lynx auto-accepts the cookies.

lynx Always allowing from domain cookies Linux screenshot

Google in Bulgarian Lynx browser screenshot

For people who care about there security (who still browse in console (surely not many anymore)), permanently allowing the cookies is not a good idea. But for those who are ready to drop off little security for convenience its ok.
 

How to install and configure Jabber Server (Ejabberd) on Debian Lenny GNU / Linux

Wednesday, December 28th, 2011

Ejabberd server erlang logo hedgehog

I've recently installed a jabber server on one Debian Lenny server and hence decided to describe my installations steps hoping this would help ppl who would like to run their own jabber server on Debian . After some research of the jabber server softwares available, I decided to install Ejabberd

The reasons I choose Ejabberd is has rich documentation, good community around the project and the project in general looks like one of the best free software jabber servers available presently. Besides that ejabberd doesn't need Apache or MySQL and only depends on erlang programming language.

Here is the exact steps I followed to have installed and configured a running XMPP jabber server.

1. Install Ejabberd with apt

The installation of Ejabberd is standard, e.g.:

debian:~# apt-get --yes install ejabberd

Now as ejabberd is installed, some minor configuration is necessery before the server can be launched:

2. Edit /etc/ejabberd/ejabberd.cfg

Inside I changed the default settings for:

a) Uncomment%%override_acls.. Changed:

%%%% Remove the Access Control Lists before new ones are added.%%%%override_acls.

to

%%
%% Remove the Access Control Lists before new ones are added.
%%
override_acls.

b) Admin User from:

%% Admin user
{acl, admin, {user, "", "example.com"}}.

to

%% Admin user
{acl, admin, {user, "admin", "jabber.myserver-host.com"}}.

c) default %% Hostname of example.com to my real hostname:

%% Hostname
{hosts, ["jabber.myserver-host.com"]}.

The rest of the configurations in /etc/ejabberd/ejabberd.cfg can stay like it is, though it is interesting to read it carefully before continuing as, there are some config timings which might prevent the XMPP server from user brute force attacks as well as few other goodies like for example (ICQ, MSN , Yahoo etc.) protocol transports.

3. Add iptables ACCEPT traffic (allow) rules for ports which are used by Ejabberd

The minimum ACCEPT rules to add are:

/sbin/iptables -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -m tcp --dport 5222 -j ACCEPT
/sbin/iptables -A INPUT -p udp -m udp --dport 5222 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -m tcp --dport 5223 -j ACCEPT
/sbin/iptables -A INPUT -p udp -m udp --dport 5223 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -m tcp --dport 5269 -j ACCEPT
/sbin/iptables -A INPUT -p udp -m udp --dport 5269 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -m tcp --dport 5280 -j ACCEPT
/sbin/iptables -A INPUT -p udp -m udp --dport 5280 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -m tcp --dport 4369 -j ACCEPT
/sbin/iptables -A INPUT -p udp -m udp --dport 4369 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -m tcp --dport 53873 -j ACCEPT

Of course if there is some specific file which stores iptables rules or some custom firewall these rules has to be added / modified to fit appropriate place or chain.

4. Restart ejabberd via init.d script

debian:~# /etc/init.d/ejabberd restart
Restarting jabber server: ejabberd is not running. Starting ejabberd.

5. Create ejabberd necessery new user accounts

debian:~# /usr/sbin/ejabberdctl register admin jabber.myserver-host.com mypasswd1
debian:~# /usr/sbin/ejabberdctl register hipo jabber.myserver-host.com mypasswd2
debian:~# /usr/sbin/ejabberdctl register newuser jabber.myserver-host.com mypasswd3
debian:~# /usr/sbin/ejabberdctl register newuser1 jabber.myserver-host.com mypasswd4
...
etc.

ejabberdctl ejabberd server client (frontend) has multiple other options and the manual is a good reading.

One helpful use of ejabberdctl is:

debian:~# /usr/sbin/ejabberdctl status
Node ejabberd@debian is started. Status: started
ejabberd is running

ejabberctl can be used also to delete some existent users, for example to delete the newuser1 just added above:

debian:~# /usr/sbin/ejabberdctl unregister newuser jabber.myserver-host.com

6. Post install web configurations

ejabberd server offers a web interface listening on port 5280, to access the web interface right after it is installed I used URL: http://jabber.myserver-host.com:5280/admin/

To login to http://jabber.myserver-host.com:5280/admin/ you will need to use the admin username previously added in this case:
admin@jabber.myserver-host.com mypasswd1

Anyways in the web interface there is not much of configuration options available for change.

7. Set dns SRV records

I'm using Godaddy 's DNS for my domain so here is a screenshot on the SRV records that needs to be configured on Godaddy:

GoDaddy DNS SRV records screenshot

In the screenshto Target is the Fually qualified domain hostname for the jabber server.

Setting the SRV records for the domain using Godaddy's DNS could take from 24 to 48 hours to propagate the changes among all the global DNS records so be patient.

If instead you use own custom BIND DNS server the records that needs to be added to the respective domain zone file are:

_xmpp-client._tcp 900 IN SRV 5 0 5222 jabber.myserver-host.com.
_xmpp-server._tcp 900 IN SRV 5 0 5269 jabber.myserver-host.com.
_jabber._tcp 900 IN SRV 5 0 5269 jabber.myserver-host.com.

8. Testing if the SRV dns records for domain are correct

debian:~$ nslookup
> set type=SRV
> jabber.myserver-host.com
 ...
> myserver-host.com

 If all is fine above nslookup request should return the requested domain SRV records.
You might be wondering what is the purpose of setting DNS SRV records at all, well if your jabber server has to communicate with the other jabber servers on the internet using the DNS SRV record is the way your server will found the other ones and vice versa.

DNS records can also be checked with dig for example

$ dig SRV _xmpp-server._tcp.mydomain.net

[…]

;; QUESTION SECTION:
;_xmpp-server._tcp.mydomain.net. IN SRV

;; ANSWER SECTION:
_xmpp-server._tcp.mydomain.net. 259200 IN SRV 5 0 5269 jabber.mydomain.net.

;; ADDITIONAL SECTION:
jabber.mydomain.net. 259200 IN A 11.22.33.44

;; Query time: 109 msec
;; SERVER: 212.27.40.241#53(212.27.40.241)
;; WHEN: Sat Aug 14 14:14:22 2010
;; MSG SIZE rcvd: 111

9. Debugging issues with ejabberd

Ejabberd log files are located in /var/log/ejabberd , you will have to check the logs in case of any issues with the jabber XMPP server. Here is the three files which log messages from ejabberd:

debian:~$ ls -1 /var/log/ejabberd/
ejabberd.log
erl_crash.dump
sasl.log

I will not get into details on the logs as the best way to find out about them is to read them 😉

10. Testing ejabberd server with Pidgin

To test if my Jabber server works properly I used Pidgin universal chat client . However there are plenty of other multiplatform jabber clients out there e.g.: Psi , Spark , Gajim etc.

Here is a screenshot of my (Accounts -> Manage Accounts -> Add) XMPP protocol configuration

Pidgin account configuration XMPP on debian Linux
 

Fixing / Resolving Fullscreen Adobe Flash issues in Debian Linux

Monday, April 11th, 2011

Adobe Flash Player ugly Logo!

If you’re experiencing problems with maximising flash (let’s say youtube) videos on your Debian or Ubuntu or any other debian derivative.
You’re not the only one! I myself has often experienced the same annoying issue.

The flash fullscreen failures or slownesses are caused by flash player’s attempts to use directly your machine hardware, as Linux kernel is rather different than Windows and the guys from Macromedia are creating always a way more buggy port of flash for unix than it’s windows versions, it’s quite normal that the flash player is unable to properly address the computer hardware on Linux.

As i’m not programmer and I couldn’t exactly explain the cause for the fullscreen flash player mishaps, I’ll skip this and right give you the two command lines solution:

debian:~# mkdir /etc/adobe
debian:~# echo "OverrideGPUValidation = 1" >> /etc/adobe/mms.cfg

This should fix it for, you now just restart your Icedove (Firefox), Epiphany Opera or whatever browser you’re used to and launch some random video in youtube to test the solution, hopefully it should be okay 😉 But you never know with flash let’s just hope that very soon the open flash alternative gnash will be production ready and at last we the free software users will be freed from the evil “slavery” of adobe’s non-free flash player!
Though this tip is tested on Debian based Linux distributions it should most likely work same in all kind of other Linuxes.

The tip should also probably have effect in FreeBSD, though the location of the adobe directory and mms.cfg should probably be /usr/local/etc/adobe, I’ll be glad to hear from some FreeBSD user if including the OverrideGPUValidation = 1 flash option to mms.cfg like below:

# mkdir /usr/local/etc/adobe
# echo "OverrideGPUValidation = 1" >> /usr/local/etc/adobe/mms.cfg

would have an impact on any flash player fullscreen issues on FreeBSD and other BSD direvative OSes that run the linux-flash port.