How to install munin linux system monitor system25.08.17

Apache is used to show the Munin pages, the apache fcgid module is required for the Munin graph zoom feature. Install apache and the fcgid module with apt.

apt-get install apache2 libcgi-fast-perl libapache2-mod-fcgid

Enable the fcgid module in apache.

a2enmod fcgid

2 Install and Configure Munin

To install Munin on Debian Jessie, we do this:

apt-get install munin munin-node munin-plugins-extra

When the server is running MySQL or MariaDB, then enable the a few extra Munin plugins to monitor MySQL:

cd /etc/munin/plugins
ln -s /usr/share/munin/plugins/mysql_ mysql_
ln -s /usr/share/munin/plugins/mysql_bytes mysql_bytes
ln -s /usr/share/munin/plugins/mysql_innodb mysql_innodb
ln -s /usr/share/munin/plugins/mysql_isam_space_ mysql_isam_space_
ln -s /usr/share/munin/plugins/mysql_queries mysql_queries
ln -s /usr/share/munin/plugins/mysql_slowqueries mysql_slowqueries
ln -s /usr/share/munin/plugins/mysql_threads mysql_threads

Next, we must edit the Munin configuration file /etc/munin/munin.conf. Uncomment the dbdir, htmldir, logdir, rundir, and tmpldir lines (the default values are fine). We want Munin to use the name server1.example.com instead of localhost.localdomain in the HTML output, therefore we replace localhost.localdomain with server1.example.com in the simple host tree section. Without the comments, the changed file looks like this:

nano /etc/munin/munin.conf

# Example configuration file for Munin, generated by 'make build'

# The next three variables specifies where the location of the RRD
# databases, the HTML output, logs and the lock/pid files. They all
# must be writable by the user running munin-cron. They are all
# defaulted to the values you see here.
#
dbdir /var/lib/munin
htmldir /var/cache/munin/www
logdir /var/log/munin
rundir /var/run/munin

# Where to look for the HTML templates
#
tmpldir /etc/munin/templates

# Where to look for the static www files
#
#staticdir /etc/munin/static

# temporary cgi files are here. note that it has to be writable by
# the cgi user (usually nobody or httpd).
#
# cgitmpdir /var/lib/munin/cgi-tmp

# (Exactly one) directory to include all files from.
includedir /etc/munin/munin-conf.d
[...]
# a simple host tree
[server1.example.com]
 address 127.0.0.1
 use_node_name yes
[...]

We should find the Apache 2.4 configuration file for Munin /etc/munin/apache24.conf - it defines an alias called munin to munin's HTML output directory /var/cache/munin/www which means we can access munin from all websites on this server by using the relative path /munin (e.g. http://www.example.com/munin).

The apache Munin configuration is not enabled by default, this has been changed from DebianWheezy to Jessie. The new config directory is /etc/apache2/conf-enabled instead of /etc/apache2/conf.d which was used in older versions like Wheezy and Squeeze.

Run these commands to enable and load the configuration into apache.

cd /etc/apache2/conf-enabled/
ln -s /etc/munin/apache24.conf munin.conf
service apache2 restart

Make sure you comment out the line Require local and add Require all granted and Options FollowSymLinks SymLinksIfOwnerMatch instead (otherwise you will only be able to access the Munin output from localhost):

nano /etc/munin/apache24.conf

Alias /munin /var/cache/munin/www
<Directory /var/cache/munin/www>
 # Require local
 Require all granted
 Options FollowSymLinks SymLinksIfOwnerMatch
 Options None
</Directory>

ScriptAlias /munin-cgi/munin-cgi-graph /usr/lib/munin/cgi/munin-cgi-graph
<Location /munin-cgi/munin-cgi-graph>
 # Require local
 Require all granted
 Options FollowSymLinks SymLinksIfOwnerMatch
 <IfModule mod_fcgid.c>
 SetHandler fcgid-script
 </IfModule>
 <IfModule !mod_fcgid.c>
 SetHandler cgi-script
 </IfModule>
</Location>

Restart Apache:

service apache2 restart

Then restart Munin:

service munin-node restart

Now wait a few minutes so that Munin can produce its first output, and then go to http://www.example.com/munin/ in your browser, and you see the first statistics:

Munin graphs

(This is just a small excerpt of the many graphics that munin produces...)

3 Password-Protect the Munin Output Directory (Optional but highly recommended)

Now it is a good idea to password-protect the munin output directory unless you want everybody to be able to see every little statistic about your server.

To do this, we must create the password file /etc/munin/munin-htpasswd. We want to login with the username admin, so we do this:

htpasswd -c /etc/munin/munin-htpasswd admin

Enter a password for admin. Then open /etc/munin/apache24.conf again...

nano /etc/munin/apache24.conf

... comment out "Require all granted and add the lines that I marked in red:

Alias /munin /var/cache/munin/www
<Directory /var/cache/munin/www>
 # Require local
 # Require all granted
 AuthUserFile /etc/munin/munin-htpasswd
 AuthName "Munin"
 AuthType Basic
 Require valid-user
 Options None
</Directory>

ScriptAlias /munin-cgi/munin-cgi-graph /usr/lib/munin/cgi/munin-cgi-graph
<Location /munin-cgi/munin-cgi-graph>
 # Require local
 # Require all granted
 AuthUserFile /etc/munin/munin-htpasswd
 AuthName "Munin"
 AuthType Basic
 Require valid-user
 <IfModule mod_fcgid.c>
 SetHandler fcgid-script
 </IfModule>
 <IfModule !mod_fcgid.c>
 SetHandler cgi-script
 </IfModule>
</Location>

Then restart Apache:

https://www.howtoforge.com/tutorial/server-monitoring-with-munin-and-monit-on-debian/

Anonymous

25.08.17

Anonymous

How to install munin linux system monitor system25.08.17

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