Docker image for munin server

Configuration

All the configuration is done through the environment.

Differences to Scalingo/docker-munin-server

• This image is based on ubuntu:20.04
• No recommended packages are installed
• munin-node is neither started or installed
• nginx worker are reduced from 4 to 1
• nginx log files are renamed (this helps if this container is behind a nginx proxy)
• health checks from bvberkum/docker-munin-server are used
• Add Timezone Support (jmdevince/docker-munin-server)
• Add Support for custom Data retaning policy

Custom Data Retention Policy

Accept Custom Graph Data Size. Link to Docu.

• GRAPH_DATA_SIZE

TimeZone Support

Accepts standard timezone names

• TZ (default UTC)

HTTP Credentials

These are the credentials used to authenticate the HTTP dashboard; both take a space-delimited list

• MUNIN_USERS
• MUNIN_PASSWORDS

SMTP info for alerts

Email credentials used to send emails (like alerts)

• SMTP_HOST
• SMTP_PORT
• SMTP_USERNAME
• SMTP_PASSWORD
• SMTP_USE_TLS
• SMTP_ALWAYS_SEND
• SMTP_MESSAGE

Alert target

Email addressed used for the alerts, require SMTP credentials.

• ALERT_RECIPIENT
• ALERT_SENDER

List of the nodes to check

The port is always optional, default is 4949

• NODES format: name1:ip1[:port1] name2:ip2[:port2] …
• SNMP_NODES format: name1:ip1[:port1] …
• SSH_NODES format: name1:ip1[:port1] …

Port

Container is listening on the port 8080

Volumes

For a bit of persistency

• /var/log/munin -> logs
• /var/lib/munin -> db
• /var/run/munin -> lock and pid files
• /var/cache/munin -> file deserved by HTTP

How to use the image

docker build -t munin-server .
docker run -d \
  -p 8080:8080 \
  -v /var/log/munin:/var/log/munin \
  -v /var/log/nginx:/var/log/nginx \
  -v /var/lib/munin:/var/lib/munin \
  -v /var/run/munin:/var/run/munin \
  -v /var/cache/munin:/var/cache/munin \
  -e MUNIN_USERS='http-user another-user' \
  -e MUNIN_PASSWORDS='secret-password other-users-password' \
  -e SMTP_HOST=smtp.example.com \
  -e SMTP_PORT=587 \
  -e SMTP_USERNAME=smtp-username \
  -e SMTP_PASSWORD=smtp-password \
  -e SMTP_USE_TLS=false \
  -e SMTP_ALWAYS_SEND=true \
  -e SMTP_MESSAGE='[${var:group};${var:host}] -> ${var:graph_title} -> warnings: ${loop<,>:wfields  ${var:label}=${var:value}} / criticals: ${loop<,>:cfields  ${var:label}=${var:value}}' \
  -e [email protected] \
  -e [email protected] \
  -e NODES="server1:10.0.0.1 server2:10.0.0.2" \
  -e SNMP_NODES="router1:10.0.0.254:9999" \
  -e TZ="America/Chicago" \
  munin-server

You can now reach your munin-server on port 8080 of your host. It will display at the first run:

Munin has not run yet. Please try again in a few moments.

Every 5 minutes munin-server will interrogate its nodes and build the graphs and store the data. That's only after the first data fetching operation that the first graphs will appear.