Munin docker container

The docker container encapsulates a munin server that queries a CouchDB server and saves particular metrics. This uses the munin script detailed here.

The script that runs on the docker container is:

#!/bin/sh

rm /etc/munin/plugins/*
ln -s /usr/share/munin/plugins/couchdb /etc/munin/plugins/couchdb
DBS=`python3 /get_all_dbs.py`

cat << EOF > /etc/munin/plugin-conf.d/couchdb
[couchdb]
env.uri   http://$DB_PORT_5983_TCP_ADDR:5983
env.monitor_active_tasks  yes
env.monitor_users  yes
env.monitor_databases yes
env.databases $DBS

EOF

service munin-node start

export NODES="local:127.0.0.1"
start-munin

The command python3 /get_all_dbs.py gets all the nedm databases available on the server. This means that the munin server would need to be restarted if new databases are deployed.

This queries the CouchDB at the URL $DB_PORT_5983_TCP_ADDR:5983, which is a port that should have administrative access to the CouchDB server (to be able to save admin-only metrics). In the nEDM systems, the File-Server docker exports this port (not publicly!) already.

Starting the container

Use the command:

docker run -d -p [exported_port]:80\
  --name munin --link [NameOfCouchDBServer]:db \
  registry.hub.docker.com/mgmarino/munin-docker:latest

[NameOfCouchDBServer] should be the name of the container that hosts the CouchDB server (or provides a proxy to the CouchDB server.

Note: to ensure that the data is persistant between starting/stopping the container, use a data container and add the appropriate flags to the above command.