#Docker

Plugin: go.d.plugin Module: docker

#Overview

This collector monitors Docker containers state, health status and more.

It connects to the Docker instance via a TCP or UNIX socket and executes the following commands:

• System info.
• List images.
• List containers.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Requires netdata user to be in the docker group.

#Default Behavior

#Auto-Detection

It discovers instances running on localhost by attempting to connect to a known Docker UNIX socket: /var/run/docker.sock.

#Limits

The default configuration for this integration does not impose any limits on data collection.

#Performance Impact

Enabling collect_container_size may result in high CPU usage depending on the version of Docker Engine.

#Setup

You can configure the docker collector in two ways:

Method	Best for	How to
UI	Fast setup without editing files	Go to Nodes → Configure this node → Collectors → Jobs, search for docker, then click + to add a job.
File	If you prefer configuring via file, or need to automate deployments (e.g., with Ansible)	Edit go.d/docker.conf and add a job.

:::important

UI configuration requires paid Netdata Cloud plan.

:::

#Prerequisites

No action required.

#Configuration

#Options

The following options can be defined globally: update_every, autodetection_retry.

Config options

| Group | Option | Description | Default | Required | |:------|:-----|:------------|:--------|:---------:| | **Collection** | update_every | Data collection interval (seconds). | 1 | no | | | autodetection_retry | Autodetection retry interval (seconds). Set 0 to disable. | 0 | no | | **Target** | address | Docker daemon address. For TCP sockets: `tcp://IP:PORT`. | unix:///var/run/docker.sock | yes | | | timeout | Request timeout (seconds). | 2 | no | | **Filters** | container_selector | Container selector. Defines which containers to monitor. Uses [simple patterns](https://github.com/netdata/netdata/tree/master/src/libnetdata/simple_pattern#readme). | * | no | | **Metrics Selection** | collect_container_size | Collect container writable layer size metrics. | no | no | | **Virtual Node** | vnode | Associates this data collection job with a [Virtual Node](https://learn.netdata.cloud/docs/netdata-agent/configuration/organize-systems-metrics-and-alerts#virtual-nodes). | | no |

#via UI

Configure the docker collector from the Netdata web interface:

1. Go to Nodes.
2. Select the node where you want the docker data-collection job to run and click the :gear: (Configure this node). That node will run the data collection.
3. The Collectors → Jobs view opens by default.
4. In the Search box, type docker (or scroll the list) to locate the docker collector.
5. Click the + next to the docker collector to add a new job.
6. Fill in the job fields, then click Test to verify the configuration and Submit to save.
   • Test runs the job with the provided settings and shows whether data can be collected.
   • If it fails, an error message appears with details (for example, connection refused, timeout, or command execution errors), so you can adjust and retest.

#via File

The configuration file name for this integration is go.d/docker.conf.

The file format is YAML. Generally, the structure is:

update_every: 1
autodetection_retry: 0
jobs:
  - name: some_name1
  - name: some_name2

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/docker.conf

#Examples

#Basic

An example configuration.

jobs:
  - name: local
    address: 'unix:///var/run/docker.sock'

#Multi-instance

Note: When you define multiple jobs, their names must be unique.

Collecting metrics from local and remote instances.

Config

```yaml jobs: - name: local address: 'unix:///var/run/docker.sock' - name: remote address: 'tcp://203.0.113.10:2375' ```

#Alerts

The following alerts are available:

Alert name	On metric	Description
docker_container_unhealthy	docker.container_health_status	${label:container_name} docker container health status is unhealthy

#Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

#Per Docker instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
docker.containers_state	running, paused, stopped	containers
docker.containers_health_status	healthy, unhealthy, not_running_unhealthy, starting, no_healthcheck	containers
docker.images	active, dangling	images
docker.images_size	size	bytes

#Per container

Metrics related to containers. Each container provides its own set of the following metrics.

Labels:

Label	Description
container_name	The container's name
image	The image name the container uses

Metrics:

Metric	Dimensions	Unit
docker.container_state	running, paused, exited, created, restarting, removing, dead	state
docker.container_health_status	healthy, unhealthy, not_running_unhealthy, starting, no_healthcheck	status
docker.container_writeable_layer_size	writeable_layer	size

#Live Data

This collector exposes real-time functions for interactive troubleshooting in the Live tab.

#Containers

Retrieves container list data equivalent to docker ps -a.

This function calls the Docker Container List API with all=true and returns both running and non-running containers in a table similar to Docker CLI output.

Use cases: - Quickly inspect all containers (running, exited, paused, dead) from Netdata - Correlate container lifecycle with metric changes and alerts - Verify exposed ports, image tags, and container names without shell access

Aspect	Description
Name	Docker:container-ls
Require Cloud	yes
Performance	Executes a single Docker API request (ContainerList with all=true): • No per-container inspect requests are issued • Response size grows with total container count • Large histories with many stopped containers may return more rows
Security	Exposes container metadata that may include sensitive details: • Container command text may include runtime arguments • Image names, ports, and container names are visible • Restrict access to authorized operators
Availability	Available when: • Docker collector is initialized and connected • Docker API list-containers request succeeds • Returns HTTP 503 while collector is initializing • Returns HTTP 500 on Docker API errors • Returns HTTP 504 on timeout

#Prerequisites

No additional configuration is required.

#Parameters

This function has no parameters.

#Returns

Container inventory from Docker Engine. Each row represents one container returned by docker ps -a.

Column	Type	Unit	Visibility	Description
CONTAINER ID	string			Short container ID (12 characters).
IMAGE	string			Container image reference.
COMMAND	string			Container command as reported by Docker API.
CREATED	string			Human-readable container creation age (for example, '5 days ago').
STATUS	string			Docker status string (for example, 'Up 3 weeks' or 'Exited (0) 4 weeks ago').
State (Raw)	string		hidden	Raw Docker state value (for example, running, exited, paused, restarting, dead).
PORTS	string			Published or exposed ports summary.
NAMES	string			Container name.
Container ID (Full)	string		hidden	Full 64-character container ID.
Created (Unix)	integer	seconds	hidden	Container creation timestamp in Unix seconds.

#Troubleshooting

#Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the docker collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn't working.

• Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that's not the case on your system, open netdata.conf and look for the plugins setting under [directories].

  cd /usr/libexec/netdata/plugins.d/

• Switch to the netdata user.

  sudo -u netdata -s

• Run the go.d.plugin to debug the collector:

  ./go.d.plugin -d -m docker

To debug a specific job:

  ./go.d.plugin -d -m docker -j jobName

#Getting Logs

If you're encountering problems with the docker collector, follow these steps to retrieve logs and identify potential issues:

• Run the command specific to your system (systemd, non-systemd, or Docker container).
• Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

#System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep docker

#System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector's name:

grep docker /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

#Docker Container

If your Netdata runs in a Docker container named "netdata" (replace if different), use this command:

docker logs netdata 2>&1 | grep docker