Add Docker metadata

The add_docker_metadata processor annotates each event with relevant metadata from Docker containers. At startup it detects a docker environment and caches the metadata. The events are annotated with Docker metadata, only if a valid configuration is detected and the processor is able to reach Docker API.

If Docker is unavailable at startup, the processor retries the connection every wait_for_metadata_retry_period (defaults to 10s) until wait_for_metadata_timeout expires. By default, retries stop after 30s. Set wait_for_metadata to true to block startup until Docker metadata is available. Set wait_for_metadata_timeout to 0 to retry indefinitely.

Each event is annotated with:

Container ID
Name
Image
Labels

Note

When running Heartbeat in a container, you need to provide access to Docker’s unix socket in order for the add_docker_metadata processor to work. You can do this by mounting the socket inside the container. For example:

docker run -v /var/run/docker.sock:/var/run/docker.sock ...

To avoid privilege issues, you may also need to add --user=root to the docker run flags. Because the user must be part of the docker group in order to access /var/run/docker.sock, root access is required if Heartbeat is running as non-root inside the container.

If Docker daemon is restarted the mounted socket will become invalid and metadata will stop working, in these situations there are two options:

Restart Heartbeat every time Docker is restarted
Mount the entire /var/run directory (instead of just the socket)

		processors:
  - add_docker_metadata:
      host: "unix:///var/run/docker.sock"
      #match_fields: ["system.process.cgroup.id"]
      #match_pids: ["process.pid", "process.parent.pid"]
      #match_source: true
      #match_source_index: 4
      #match_short_id: true
      #cleanup_timeout: 60
      #labels.dedot: true
      #wait_for_metadata: false
      #wait_for_metadata_timeout: 30s
      #wait_for_metadata_retry_period: 10s
      # To connect to Docker over TLS you must specify a client and CA certificate.
      #ssl:
      #  certificate_authority: "/etc/pki/root/ca.pem"
      #  certificate:           "/etc/pki/client/cert.pem"
      #  key:                   "/etc/pki/client/cert.key"
		
	

It has the following settings:

host: (Optional) Docker socket (UNIX or TCP socket). It uses unix:///var/run/docker.sock by default.
ssl: (Optional) SSL configuration to use when connecting to the Docker socket.
match_fields: (Optional) A list of fields to match a container ID, at least one of them should hold a container ID to get the event enriched.
match_pids: (Optional) A list of fields that contain process IDs. If the process is running in Docker then the event will be enriched. The default value is ["process.pid", "process.parent.pid"].
match_source: (Optional) Match container ID from a log path present in the log.file.path field. Enabled by default.
match_short_id: (Optional) Match container short ID from a log path present in the log.file.path field. Disabled by default. This allows to match directories names that have the first 12 characters of the container ID. For example, /var/log/containers/b7e3460e2b21/*.log.
match_source_index: (Optional) Index in the source path split by / to look for container ID. It defaults to 4 to match /var/lib/docker/containers/<container_id>/*.log
cleanup_timeout: (Optional) Time of inactivity to consider we can clean and forget metadata for a container, 60s by default.
hostfs: (Optional) Specifies the mount point of the host’s filesystem, which can be used to monitor a host from within a container.
labels.dedot: (Optional) If set to true, replaces dots in labels with _. Defaults to true.
wait_for_metadata: (Optional) When true, startup is blocked while the processor retries connecting to Docker until metadata is available. If the processor can't connect to Docker within the duration set in wait_for_metadata_timeout, startup fails and the process exits. When false, the processor starts immediately and retries the connection asynchronously until the timeout expires. Defaults to false.
wait_for_metadata_timeout: (Optional) The maximum time allowed for the initial Docker connection attempt and subsequent retries at startup. Applies regardless of wait_for_metadata. To retry the connection indefinitely, set to 0. Defaults to 30s.
wait_for_metadata_retry_period: (Optional) How long to wait between Docker connection retry attempts after a failed attempt. Defaults to 10s.