Docker an open-source project that automates the deployment of software applications inside containers.

Configure Docker

To monitor a Docker engine, the first step is to specify the metrics-address. The best way to do this is via the daemon.json, which is located at one of the following locations by default. If the file does not exist, create it.

  • Linux: /etc/docker/daemon.json
  • Windows Server: C:\ProgramData\docker\config\daemon.json
  • Docker Desktop for Mac / Docker Desktop for Windows: Click the Docker icon in the toolbar, select Preferences, then select “Docker Engine”.

If the file is currently empty, paste the following:

{
  "metrics-addr" : "0.0.0.0:9323",
  "experimental" : true
}

This will publish the metrics endpoint, in the port 9323 of the host.

After Docker restars, use web browser pointing to http://192.168.2.13:9323 (assuming the IP of the Docker engine’s machine is 192.168.2.13). A sample result:

# HELP builder_builds_failed_total Number of failed image builds
# TYPE builder_builds_failed_total counter
builder_builds_failed_total{reason="build_canceled"} 0
builder_builds_failed_total{reason="build_target_not_reachable_error"} 0
builder_builds_failed_total{reason="command_not_supported_error"} 0
builder_builds_failed_total{reason="dockerfile_empty_error"} 0
builder_builds_failed_total{reason="dockerfile_syntax_error"} 0
builder_builds_failed_total{reason="error_processing_commands_error"} 0
builder_builds_failed_total{reason="missing_onbuild_arguments_error"} 0
builder_builds_failed_total{reason="unknown_instruction_error"} 0
# HELP builder_builds_triggered_total Number of triggered image builds
# TYPE builder_builds_triggered_total counter
builder_builds_triggered_total 0
# HELP engine_daemon_container_actions_seconds The number of seconds it takes to process each container action
# TYPE engine_daemon_container_actions_seconds histogram
engine_daemon_container_actions_seconds_bucket{action="changes",le="0.005"} 1
engine_daemon_container_actions_seconds_bucket{action="changes",le="0.01"} 1
engine_daemon_container_actions_seconds_bucket{action="changes",le="0.025"} 1
engine_daemon_container_actions_seconds_bucket{action="changes",le="0.05"} 1
engine_daemon_container_actions_seconds_bucket{action="changes",le="0.1"} 1
engine_daemon_container_actions_seconds_bucket{action="changes",le="0.25"} 1
engine_daemon_container_actions_seconds_bucket{action="changes",le="0.5"} 1
engine_daemon_container_actions_seconds_bucket{action="changes",le="1"} 1
engine_daemon_container_actions_seconds_bucket{action="changes",le="2.5"} 1

Configure SysUpTime

  1. Add a web site monitor: add monitor

    In the URL field, enter

    http://192.168.2.13:9323/metrics
(Replace 192.168.2.13 with real docker engine's IP address)

  2. Press “Configure” button next to the “Threshold settings”. add monitor

Move “body response time” to the left and move “content match” to the right panel.

  1. Configure it to use simple content match, and choose “Line contains” radio button, enter 
    engine_daemon_container_states_containers{state="running"}

    to the text field of “Line contains”. In the token field, enter “2”. The value is the second token of the line. add monitor

  2. We don’t need to check threshold, so uncheck “Enable threshold” on the top. add monitor

  3. Press “Ok” buttons to save the monitor.

  4. (Optional) In the “Manage Monitor” dialog, select the newly created monitor and press “Chart” button to see the real time chart. add monitor

Now we have created a monitor to check docker parameter:

engine_daemon_container_states_containers{state="running"}

Then we can create similar monitors for other parameters such as

engine_daemon_container_states_containers{state="paused"}
engine_daemon_container_states_containers{state="stopped"}
engine_daemon_health_checks_failed_total
swarm_node_manager