Posts Tagged ‘based’

How to enable HaProxy logging to a separate log /var/log/haproxy.log / prevent HAProxy duplicate messages to appear in /var/log/messages

Wednesday, February 19th, 2020

haproxy-logging-basics-how-to-log-to-separate-file-prevent-duplicate-messages-haproxy-haproxy-weblogo-squares
haproxy  logging can be managed in different form the most straight forward way is to directly use /dev/log either you can configure it to use some log management service as syslog or rsyslogd for that.

If you don't use rsyslog yet to install it: 

# apt install -y rsyslog

Then to activate logging via rsyslogd we can should add either to /etc/rsyslogd.conf or create a separte file and include it via /etc/rsyslogd.conf with following content:
 

Enable haproxy logging from rsyslogd


Log haproxy messages to separate log file you can use some of the usual syslog local0 to local7 locally used descriptors inside the conf (be aware that if you try to use some wrong value like local8, local9 as a logging facility you will get with empty haproxy.log, even though the permissions of /var/log/haproxy.log are readable and owned by haproxy user.

When logging to a local Syslog service, writing to a UNIX socket can be faster than targeting the TCP loopback address. Generally, on Linux systems, a UNIX socket listening for Syslog messages is available at /dev/log because this is where the syslog() function of the GNU C library is sending messages by default. To address UNIX socket in haproxy.cfg use:

log /dev/log local2 


If you want to log into separate log each of multiple running haproxy instances with different haproxy*.cfg add to /etc/rsyslog.conf lines like:

local2.* -/var/log/haproxylog2.log
local3.* -/var/log/haproxylog3.log


One important note to make here is since rsyslogd is used for haproxy logging you need to have enabled in rsyslogd imudp and have a UDP port listener on the machine.

E.g. somewhere in rsyslog.conf or via rsyslog include file from /etc/rsyslog.d/*.conf needs to have defined following lines:

$ModLoad imudp
$UDPServerRun 514


I prefer to use external /etc/rsyslog.d/20-haproxy.conf include file that is loaded and enabled rsyslogd via /etc/rsyslog.conf:

# vim /etc/rsyslog.d/20-haproxy.conf

$ModLoad imudp
$UDPServerRun 514​
local2.* -/var/log/haproxy2.log


It is also possible to produce different haproxy log output based on the severiy to differentiate between important and less important messages, to do so you'll need to rsyslog.conf something like:
 

# Creating separate log files based on the severity
local0.* /var/log/haproxy-traffic.log
local0.notice /var/log/haproxy-admin.log

 

Prevent Haproxy duplicate messages to appear in /var/log/messages

If you use local2 and some default rsyslog configuration then you will end up with the messages coming from haproxy towards local2 facility producing doubled simultaneous records to both your pre-defined /var/log/haproxy.log and /var/log/messages on Proxy servers that receive few thousands of simultanous connections per second.
This is a problem since doubling the log will produce too much data and on systems with smaller /var/ partition you will quickly run out of space + this haproxy requests logging to /var/log/messages makes the file quite unreadable for normal system events which are so important to track clearly what is happening on the server daily.

To prevent the haproxy duplicate messages you need to define somewhere in rsyslogd usually /etc/rsyslog.conf local2.none near line of facilities configured to log to file:

*.info;mail.none;authpriv.none;cron.none;local2.none     /var/log/messages

This configuration should work but is more rarely used as most people prefer to have haproxy log being written not directly to /dev/log which is used by other services such as syslogd / rsyslogd.

To use /dev/log to output logs from haproxy configuration in global section use config like:
 

global
        log /dev/log local2 debug
        chroot /var/lib/haproxy
        stats socket /run/haproxy/admin.sock mode 660 level admin
        stats timeout 30s
        user haproxy
        group haproxy
        daemon

The log global directive basically says, use the log line that was set in the global section for whole config till end of file. Putting a log global directive into the defaults section is equivalent to putting it into all of the subsequent proxy sections.

Using global logging rules is the most common HAProxy setup, but you can put them directly into a frontend section instead. It can be useful to have a different logging configuration as a one-off. For example, you might want to point to a different target Syslog server, use a different logging facility, or capture different severity levels depending on the use case of the backend application. 

Insetad of using /dev/log interface that is on many distributions heavily used by systemd to store / manage and distribute logs,  many haproxy server sysadmins nowdays prefer to use rsyslogd as a default logging facility that will manage haproxy logs.
Admins prefer to use some kind of mediator service to manage log writting such as rsyslogd or syslog, the reason behind might vary but perhaps most important reason is  by using rsyslogd it is possible to write logs simultaneously locally on disk and also forward logs  to a remote Logging server  running rsyslogd service.

Logging is defined in /etc/haproxy/haproxy.cfg or the respective configuration through global section but could be also configured to do a separate logging based on each of the defined Frontend Backends or default section. 
A sample exceprt from this section looks something like:

#———————————————————————
# Global settings
#———————————————————————
global
    log         127.0.0.1 local2

    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon

    # turn on stats unix socket
    stats socket /var/lib/haproxy/stats

#———————————————————————
defaults
    mode                    tcp
    log                     global
    option                  tcplog
    #option                  dontlognull
    #option http-server-close
    #option forwardfor       except 127.0.0.0/8
    option                  redispatch
    retries                 7
    #timeout http-request    10s
    timeout queue           10m
    timeout connect         30s
    timeout client          20m
    timeout server          10m
    #timeout http-keep-alive 10s
    timeout check           30s
    maxconn                 3000

 

 

# HAProxy Monitoring Config
#———————————————————————
listen stats 192.168.0.5:8080                #Haproxy Monitoring run on port 8080
    mode http
    option httplog
    option http-server-close
    stats enable
    stats show-legends
    stats refresh 5s
    stats uri /stats                            #URL for HAProxy monitoring
    stats realm Haproxy\ Statistics
    stats auth hproxyauser:Password___          #User and Password for login to the monitoring dashboard

 

#———————————————————————
# frontend which proxys to the backends
#———————————————————————
frontend ft_DKV_PROD_WLPFO
    mode tcp
    bind 192.168.233.5:30000-31050
    option tcplog
    log-format %ci:%cp\ [%t]\ %ft\ %b/%s\ %Tw/%Tc/%Tt\ %B\ %ts\ %ac/%fc/%bc/%sc/%rc\ %sq/%bq
    default_backend Default_Bakend_Name


#———————————————————————
# round robin balancing between the various backends
#———————————————————————
backend bk_DKV_PROD_WLPFO
    mode tcp
    # (0) Load Balancing Method.
    balance source
    # (4) Peer Sync: a sticky session is a session maintained by persistence
    stick-table type ip size 1m peers hapeers expire 60m
    stick on src
    # (5) Server List
    # (5.1) Backend
    server Backend_Server1 10.10.10.1 check port 18088
    server Backend_Server2 10.10.10.2 check port 18088 backup


The log directive in above config instructs HAProxy to send logs to the Syslog server listening at 127.0.0.1:514. Messages are sent with facility local2, which is one of the standard, user-defined Syslog facilities. It’s also the facility that our rsyslog configuration is expecting. You can add more than one log statement to send output to multiple Syslog servers.

Once rsyslog and haproxy logging is configured as a minumum you need to restart rsyslog (assuming that haproxy config is already properly loaded):

# systemctl restart rsyslogd.service

To make sure rsyslog reloaded successfully:

systemctl status rsyslogd.service


Restarting HAproxy

If the rsyslogd logging to 127.0.0.1 port 514 was recently added a HAProxy restart should also be run, you can do it with:
 

# /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -D -p /var/run/haproxy.pid -sf $(cat /var/run/haproxy.pid)


Or to restart use systemctl script (if haproxy is not used in a cluster with corosync / heartbeat).

# systemctl restart haproxy.service

You can control how much information is logged by adding a Syslog level by

    log         127.0.0.1 local2 info


The accepted values are the standard syslog security level severity:

Value Severity Keyword Deprecated keywords Description Condition
0 Emergency emerg panic System is unusable A panic condition.
1 Alert alert   Action must be taken immediately A condition that should be corrected immediately, such as a corrupted system database.
2 Critical crit   Critical conditions Hard device errors.
3 Error err error Error conditions  
4 Warning warning warn Warning conditions  
5 Notice notice   Normal but significant conditions Conditions that are not error conditions, but that may require special handling.
6 Informational info   Informational messages  
7 Debug debug   Debug-level messages Messages that contain information normally of use only when debugging a program.

 

Logging only errors / timeouts / retries and errors is done with option:

Note that if the rsyslog is configured to listen on different port for some weird reason you should not forget to set the proper listen port, e.g.:
 

  log         127.0.0.1:514 local2 info

option dontlog-normal

in defaults or frontend section.

You most likely want to enable this only during certain times, such as when performing benchmarking tests.

(or log-format-sd for structured-data syslog) directive in your defaults or frontend
 

Haproxy Logging shortly explained


The type of logging you’ll see is determined by the proxy mode that you set within HAProxy. HAProxy can operate either as a Layer 4 (TCP) proxy or as Layer 7 (HTTP) proxy. TCP mode is the default. In this mode, a full-duplex connection is established between clients and servers, and no layer 7 examination will be performed. When in TCP mode, which is set by adding mode tcp, you should also add option tcplog. With this option, the log format defaults to a structure that provides useful information like Layer 4 connection details, timers, byte count and so on.

Below is example of configured logging with some explanations:

Log-format "%ci:%cp [%t] %ft %b/%s %Tw/%Tc/%Tt %B %ts %ac/%fc/%bc/%sc/%rc %sq/%bq"

haproxy-logged-fields-explained
Example of Log-Format configuration as shown above outputted of haproxy config:

Log-format "%ci:%cp [%tr] %ft %b/%s %TR/%Tw/%Tc/%Tr/%Ta %ST %B %CC %CS %tsc %ac/%fc/%bc/%sc/%rc %sq/%bq %hr %hs %{+Q}r"

haproxy_http_log_format-explained1

To understand meaning of this abbreviations you'll have to closely read  haproxy-log-format.txt. More in depth info is to be found in HTTP Log format documentation

 

Logging HTTP request headers

HTTP request header can be logged via:
 

 http-request capture

frontend website
    bind :80
    http-request capture req.hdr(Host) len 10
    http-request capture req.hdr(User-Agent) len 100
    default_backend webservers


The log will show headers between curly braces and separated by pipe symbols. Here you can see the Host and User-Agent headers for a request:

192.168.150.1:57190 [20/Dec/2018:22:20:00.899] website~ webservers/server1 0/0/1/0/1 200 462 – – —- 1/1/0/0/0 0/0 {mywebsite.com|Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/71.0.3578.80 } "GET / HTTP/1.1"

 

Haproxy Stats Monitoring Web interface


Haproxy is having a simplistic stats interface which if enabled produces some general useful information like in above screenshot, through which
you can get a very basic in browser statistics and track potential issues with the proxied traffic for all configured backends / frontends incoming outgoing
network packets configured nodes
 experienced downtimes etc.

haproxy-statistics-report-picture

The basic configuration to make the stats interface accessible would be like pointed in above config for example to enable network listener on address
 

https://192.168.0.5:8080/stats


with hproxyuser / password config would be:

# HAProxy Monitoring Config
#———————————————————————
listen stats 192.168.0.5:8080                #Haproxy Monitoring run on port 8080
    mode http
    option httplog
    option http-server-close
    stats enable
    stats show-legends
    stats refresh 5s
    stats uri /stats                            #URL for HAProxy monitoring
    stats realm Haproxy\ Statistics
    stats auth hproxyauser:Password___          #User and Password for login to the monitoring dashboard

 

 

Sessions states and disconnect errors on new application setup

Both TCP and HTTP logs include a termination state code that tells you the way in which the TCP or HTTP session ended. It’s a two-character code. The first character reports the first event that caused the session to terminate, while the second reports the TCP or HTTP session state when it was closed.

Here are some essential termination codes to track in for in the log:
 

Here are some termination code examples most commonly to see on TCP connection establishment errors:

Two-character code    Meaning
—    Normal termination on both sides.
cD    The client did not send nor acknowledge any data and eventually timeout client expired.
SC    The server explicitly refused the TCP connection.
PC    The proxy refused to establish a connection to the server because the process’ socket limit was reached while attempting to connect.


To get all non-properly exited codes the easiest way is to just grep for anything that is different from a termination code –, like that:

tail -f /var/log/haproxy.log | grep -v ' — '


This should output in real time every TCP connection that is exiting improperly.

There’s a wide variety of reasons a connection may have been closed. Detailed information about all possible termination codes can be found in the HAProxy documentation.
To get better understanding a very useful reading to haproxy Debug errors with  is in haproxy-logging.txt in that small file are collected all the cryptic error messages codes you might find in your logs when you're first time configuring the Haproxy frontend / backend and the backend application behind.

Another useful analyze tool which can be used to analyze Layer 7 HTTP traffic is halog for more on it just google around.

How to Set MySQL MariaDB server root user to be able to connect from any host on the Internet / Solution to ‘ ERROR 1045 (28000): Access denied for user ‘root’@’localhost’ (using password: YES) ‘

Tuesday, September 3rd, 2019

How-to-set-up-MariaDB-server-root-admin-user-to-be-able-to-connect-from-any-host-anywhere-mariadb-seal-logo-picture

In this small article, I'll shortly explain on how I setup a Standard default package MariaDB Database server on Debian 10 Buster Linux and how I configured it to be accessible from any hostname on the Internet in order to make connection from remote Developer PC with MySQL GUI SQL administration tools such as MySQL WorkBench / HeidiSQL / Navicat / dbForge   as well as the few set-backs experienced in the process (e.g. what was the reason for ' ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) '  error and its solution.

Setting new or changing old MariaDB (MySQL) root server password

 

I've setup a brand new MariaDB database (The new free OpenSource software fork of MySQL) mariadb-server-10.3 on a Debian 10, right after the OS was installed with the usual apt command:

# apt install mariadb-server

Next tep was to change the root access password which was set to empty pass by default, e.g. connected with mysql CLI locally while logged via SSH on server and run:

MariaDB [(none)]> mysql -u root -p

use mysql;
update user set authentication_string=PASSWORD("MyChosenNewPassword") where User='root';

There was requirement by the customer, that MySQL server is not only accessed locally but be accessed from any IP address from anywhere on the Internet, so next step was to do so.

Allowing access to MySQL server from Anywhere

Allowing access from any host to MariaDB SQL server  is a bad security practice but as the customer is the King I've fulfilled this weird wish too, by changing the listener for MariaDB (MySQL) on Debian 10 codenamed Buster
 
changing the default listener
to be not the default 127.0.0.1 (localhost) but any listener is done by modifying the bind-address directive in conf /etc/mysql/mariadb.conf.d/50-server.cnf:

root@linux:~# vim /etc/mysql/mariadb.conf.d/50-server.cnf

Then comment out

bind-address  = 127.0.0.1

and  add instead 0.0.0.0 (any listener)

 

bind-address  = 0.0.0.0
root@linux:/etc/mysql/mariadb.conf.d# grep -i bind-address 50-server.cnf
##bind-address            = 127.0.0.1
bind-address    = 0.0.0.0


Then to make the new change effective restart MariaDB (luckily still using the old systemV init script even though systemd is working.
 

root@linux:~# /etc/init.d/mysql restart
[ ok ] Restarting mysql (via systemctl): mysql.service.


To make sure it is properly listening on MySQL defaults TCP port 3306, then as usual used netcat.

root@pritchi:~# netstat -etna |grep -i 3306
tcp        0      0 0.0.0.0:3306            0.0.0.0:*               LISTEN      109        1479917  

 

By the way the exact mariadb.cnf used on this middle-sized front-backend server is here – the serveris planned to be a Apache Web server + Database host with MySQL DB of a middle range to be able to serve few thousand of simultaneous unique customers.

To make sure no firewall is preventing MariaDB to be accessed, I've checked for any reject rules iptables and ipset definitions, e.g.:
 

root@linux:~# iptables -L |gre -i rej

root@linux:~# ipset list

 

Then to double make sure the MySQL is allowed to access from anywhere, used simple telnet from my Desktop Laptop PC (that also runs Debian Linux) towards the server .

hipo@jeremiah:~$ telnet 52.88.235.45 3306
Trying 52.88.235.45…
Connected to 52.88.235.45.
Escape character is '^]'.
[
5.5.5-10.3.15-MariaDB-1
                       rQ}Cs>v\��-��G1[W%O>+Y^OQmysql_native_password
Connection closed by foreign host.

 

As telnet is not supporting the data encryption after TCP proto connect, in a few seconds time, remote server connection is terminated.

 

Setting MySQL user to be able to connect to local server MySQL from any remote hostname


I've connected locally to MariaDB server with mysql -u root -p and issued following set of SQL commands to make MySQL root user be able to connect from anywhere:

 

CREATE USER 'root'@'%' IDENTIFIED BY 'my-secret-pass';
GRANT ALL ON *.* TO 'root'@'localhost';
GRANT ALL ON *.* TO 'root'@'%';

 

Next step, I've took was to try logging in with root (admin) MariaDB superuser from MySQL CLI (Command Line Interface) on my desktop just to find out, I'm facing a nasty error.
 

hipo@jeremiah:~$ mysql -u root -H remote-server-hostname.com -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)


My first guess was something is wrong with my root user created in MySQL's mysql.user table (In MySQL this is the privileges table that stores, how MySQL user credentials are handled by mysqld local OS running process.

 

Changing the MySQL root (admin) password no longer possible on Debian 10 Buster?

 

The standard way ot change the MySQL root password well known via a simple dpkg-reconfigure (provided by Debian's debconf is no longer working so below command produces empty output instead of triggering the good old Ncurses text based interface well-known over the years …

 

root@linux:~# /usr/sbin/dpkg-reconfigure mariadb-server-10.3

 

 

Viewing MariaDB (MySQL) username / password set-up from the CLI

 

To list how this set-privileges looked like I've used following command:

 

MariaDB [mysql]> select * from mysql.user where User = 'root';
+———–+——+——————————————-+————-+————-+————-+————-+————-+———–+————-+—————+————–+———–+————+—————–+————+————+————–+————+———————–+——————+————–+—————–+——————+——————+—————-+———————+——————–+——————+————+————–+————————+———————+———-+————+————-+————–+—————+————-+—————–+———————-+———————–+———————–+——————+———+————–+——————–+
| Host      | User | Password                                  | Select_priv | Insert_priv | Update_priv | Delete_priv | Create_priv | Drop_priv | Reload_priv | Shutdown_priv | Process_priv | File_priv | Grant_priv | References_priv | Index_priv | Alter_priv | Show_db_priv | Super_priv | Create_tmp_table_priv | Lock_tables_priv | Execute_priv | Repl_slave_priv | Repl_client_priv | Create_view_priv | Show_view_priv | Create_routine_priv | Alter_routine_priv | Create_user_priv | Event_priv | Trigger_priv | Create_tablespace_priv | Delete_history_priv | ssl_type | ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections | plugin                | authentication_string | password_expired | is_role | default_role | max_statement_time |
+———–+——+——————————————-+————-+————-+————-+————-+————-+———–+————-+—————+————–+———–+————+—————–+————+————+————–+————+———————–+——————+————–+—————–+——————+——————+—————-+———————+——————–+——————+————+————–+————————+———————+———-+————+————-+————–+—————+————-+—————–+———————-+———————–+———————–+——————+———+————–+——————–+
| localhost | root | *E6D338325F50177F2F6A15EDZE932D68C88B8C4F | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                | Y          | Y            | Y                      | Y                   |          |            |             |              |             0 |           0 |               0 |                    0 | mysql_native_password |                       | N                | N       |              |           0.000000 |
| %         | root | *E6D338325F50177F2F6A15EDZE932D68C88B8C4F | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | N          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                | Y          | Y            | Y                      | Y                   |          |            |             |              |             0 |           0 |               0 |                    0 |                       |                       | N                | N       |              |           0.000000 |
+———–+——+——————————————-+————-+————-+————-+————-+————-+———–+————-+—————+————–+———–+————+—————–+————+————+————–+————+———————–+——————+————–+—————–+——————+——————+—————-+———————+——————–+——————+————+————–+————————+———————+———-+————+————-+————–+—————+————-+—————–+———————-+———————–+———————–+——————+———+————–+——————–+

 

The hashed (encrypted) password string is being changed from the one on the server, so please don't try to hack me (decrypt it) 🙂
As it is visible from below output the Host field for root has the '%' string which means, any hostname is authorized to be able to connect and login to the MySQL server, so this was not the problem.

After quite some time on reading on what causes
' ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
',
I've spend some time reading various forum discussions online on the err such as the one on StackOverflow here SuperUser.com's  how to fix access denied for user 'root'@'localhost' and one on askubuntu.com's – ERROR 1045(28000) : Access denied for user 'root@localhost' (using password: no ) and after a while finally got it, thanks to a cool IRC.FREENODE.NET guy nicknamed, hedenface who pointed me I'm that, I'm trying to use the -H flag (Prodice HTML) instead of -h (host_name), it seems somehow I ended up with the wrong memory that the -H stands for hostname, by simply using -h I could again login Hooray!!!

 

root@linux:~$ mysql -u root -h remote-server-host.com -p
Enter password:
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 14
Server version: 10.3.15-MariaDB-1 Debian 10

 

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


I've further asked the customer to confirm, he can connect also from his Microsoft Windows 10 PC situated on a different LAN network and got his confirmation. Few notes to make here is I've also installed phpmyadmin on the server using phpmyadmin php source code latest version, as in Debian 10 it seems the good old PHP is no longer available (as this crazy developers again made a mess and there is no phpmyadmin .deb package in Debian Buster – but that's a different story I'll perhaps try to document in some small article in future.

Linux / FreeBSD Text Based Gallery Generator (llgal, igal, igal2, bbgallery)

Monday, September 14th, 2009

Recently I was looking for a handy way to generate nice html or php like gallery.After some asking in freenode and some help provided by some guys from #debian chanas well as some personal research. I came across 4 handy progs that works like a charm.Here is a list of the generators:
1. llgal (llgal is an easy and fast on-line gallery generator based on iGal)
2. igal1 and igal2 (igal is a quick and easy program for placing your images online.)
3. bbgallery (small perl script generating the galleries)
.All of this gives you a way to modify the default templates according to your willings.
Be aware that bbgallery requires perl html compatability.
A small example of what you can expect from the newly generated gallery can be seen here generated with llgal and some more here generated with igal .
I personally liked more the generated default galleries with igal because they looked a bit more fancy although that llgal includes a way more advanced possibilities and options.
One of the main things that could lead you into using llgal instead of igal is that llgal supports generation of galleries from directories and subdirectories in a recursive manner, where the end generated output lists you all your pictures from directories and it’s sublinks into a common gallery right into the root directory it was executed.
One more helpful tip in case if you decide to include all subdirectories in a unique gallery use:
llgal –Pall .
llgal comes with a handy howto that describes many of the fancy llgal features.
Hope you have some fun with this three.
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