Munin Dynazoom not working on Ubuntu - apache2

Question

I recently installed Munin on my machines. I got everything to work and the data is actually being drawn on the graphs! :)
But, for some reason, when I click on each individual graph, it brings me to the dynazoom page but it's all plain text with no images :(
Here is my apache.conf:
# Enable this for template generation
Alias /munin /var/cache/munin/www
# Enable this for cgi-based templates
#Alias /munin-cgi/static /var/cache/munin/www/static
#ScriptAlias /munin-cgi /usr/lib/munin/cgi/munin-cgi-html
#<Location /munin-cgi>
# Order allow,deny
# Allow from localhost 127.0.0.0/8 ::1
# AuthUserFile /etc/munin/munin-htpasswd
# AuthName "Munin"
# AuthType Basic
# require valid-user
#</Location>
<Directory /var/cache/munin/www>
Order allow,deny
# Allow from localhost 127.0.0.0/8 ::1
Allow from all
Options None
AllowOverride None
# This file can be used as a .htaccess file, or a part of your apache
# config file.
#
# For the .htaccess file option to work the munin www directory
# (/var/cache/munin/www) must have "AllowOverride all" or something
# close to that set.
#
AuthUserFile /etc/munin/munin-htpasswd
AuthName "Munin"
AuthType Basic
require valid-user
# This next part requires mod_expires to be enabled.
#
# Set the default expiration time for files to 5 minutes 10 seconds from
# their creation (modification) time. There are probably new files by
# that time.
#
<IfModule mod_expires.c>
ExpiresActive On
ExpiresDefault M310
</IfModule>
</Directory>
# Enables fastcgi for munin-cgi-html if present
#<Location /munin-cgi>
# <IfModule mod_fastcgi.c>
# SetHandler fastcgi-script
# </IfModule>
#</Location>
#<Location /munin-cgi/static>
# SetHandler None
#</Location>
# Enables fastcgi for munin-cgi-graph if present
ScriptAlias /munin-cgi/munin-cgi-graph /usr/lib/munin/cgi/munin-cgi-graph
<Location /munin-cgi/munin-cgi-graph>
Order allow,deny
Allow from localhost 127.0.0.0/8 ::1
# 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>
ScriptAlias /munin-cgi/munin-cgi-html /usr/lib/munin/cgi/munin-cgi-html
<Location /munin-cgi/munin-cgi-html>
Order allow,deny
Allow from localhost 127.0.0.0/8 ::1
# 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>
Any reason why this could not be working? If I haven't given enough information, please let me know. Thank you

Answer 1

Enabling the apache2 cgi (or cgid) makes the dynazoom work.
sudo a2enmod cgi; sudo service apache2 restart

Answer 2

I had the same issue on Ubuntu 14.04.
By checking /var/log/apache2/error.log I found the script complaining about missing modules:
Can't locate CGI/Fast.pm in #INC (you may need to install the CGI::Fast module) (#INC contains: /etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /usr/local/lib/site_perl) at /usr/lib/munin/cgi/munin-cgi-graph line 36.
I did install the CGI::Fast module to solve the issue:
sudo apt-get install libcgi-fast-perl
There is no need for any rewrite rule as indicated in another answer. Packages in Ubuntu 14.04 have the path names configured correctly.

Answer 3

In addition to ermannob's answer; my apache2 error.log reported
AH01797: client denied by server configuration: /usr/lib/munin/cgi/munin-cgi-graph
which stopped me from messing around with file permissions within the OS and caused me to look at the apache config. All that was required was to change
<Location /munin-cgi/munin-cgi-graph>
Order allow,deny
Allow from localhost 127.0.0.0/8 ::1
...
in /etc/apache2/conf-enabled/munin.conf, to
<Location /munin-cgi/munin-cgi-graph>
Require all granted
Options FollowSymLinks SymLinksIfOwnerMatch
I did not need to install any fastcgi packages and followed the tutorial here. They suggest that configuration be added to the apache.conf file directly, however, relaxing the permissions in the conf-enabled/munin.conf file (for /munin, /munin-cgi/munin-cgi-graph and /munin-cgi/munin-cgi-html) was sufficient. I omitted the changes to apache.conf.

Answer 4

When running Ubuntu 14.04 I fixed this on my own servers by updating the apache config in /etc/apache2/conf-available/munin.conf from 2.2 style to 2.4
Example:
<Directory /var/cache/munin/www>
Order allow,deny
Allow from localhost 127.0.0.0/8 ::1
....
</Directory>
needs to be changed to
<Directory /var/cache/munin/www>
# Order allow,deny
# Allow from localhost 127.0.0.0/8 ::1
Require all granted
....
</Directory>
or you could do
Require host localhost
or
Require ip 127.0.0.0/8 ::8
see apache documentation about the changes here. By the time I realized this, I had already gone through and installed FastCGI and the perl module listed in this thread. This change would need to be done to all the location/directory areas you see in munin.conf.

Answer 5

I had the same problem on Debian 8. I've edited the file /etc/munin/apache24.conf like that:
Alias /munin /var/cache/munin/www
<Directory /var/cache/munin/www>
Require all granted
Options FollowSymLinks SymLinksIfOwnerMatch
</Directory>
ScriptAlias /munin-cgi/munin-cgi-graph /usr/lib/munin/cgi/munin-cgi-graph
<Location /munin-cgi/munin-cgi-graph>
Require all granted
Options FollowSymLinks SymLinksIfOwnerMatch
<IfModule mod_fcgid.c>
SetHandler fcgid-script
</IfModule>
<IfModule !mod_fcgid.c>
SetHandler cgi-script
</IfModule>
</Location>
Then I installed the libapache2-mod-fcgid as mentioned earlier.
After a munin-node restart, it's working correctly.

Answer 6

You should change the configuration part about the munin-cgi-graph, setting the same permissions as the main section. Here's your configuration:
# Enables fastcgi for munin-cgi-graph if present
ScriptAlias /munin-cgi/munin-cgi-graph /usr/lib/munin/cgi/munin-cgi-graph
<Location /munin-cgi/munin-cgi-graph>
Order allow,deny
Allow from localhost 127.0.0.0/8 ::1
# 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>
change it to this:
# Enables fastcgi for munin-cgi-graph if present
ScriptAlias /munin-cgi/munin-cgi-graph /usr/lib/munin/cgi/munin-cgi-graph
<Location /munin-cgi/munin-cgi-graph>
Order allow,deny
# Allow from localhost 127.0.0.0/8 ::1
Allow from all
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>
Additionally I had to install the libcgi-fast-perl package, doing this:
sudo apt-get install libcgi-fast-perl
Checking /var/log/apache2/error.log helped me a lot.

Answer 7

I had experienced the same behavior in Ubuntu 14.04 LTS. The reason was the image URL in the dynazoom page was incorrectly using /cgi-bin/munin-cgi-graph/ instead of /munin-cgi/munin-cgi/graph/ so instead of hunting down in the code to fix this bug I worked around it with a quick rewrite rule:
RewriteRule ^/cgi-bin/munin-cgi-graph/(.*) /$1
Hope this helps

Answer 8

In my case following https://bugs.launchpad.net/ubuntu/+source/munin/+bug/1258026 and http://munin-monitoring.org/wiki/MuninConfigurationMasterCGI worked.
The only problematic part was where to put Apache virtual host configuration, it turned out that placing it at /etc/apache2/sites-enabled/001-munin.conf worked.