Add Docker metadata

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Inputs that collect logs and metrics use this processor by default, so you do not need to configure it explicitly.

The add_docker_metadata processor annotates each event with relevant metadata from Docker containers. At startup the processor detects a Docker environment and caches the metadata.

For events to be annotated with Docker metadata, the configuration must be valid, and the processor must be able to reach the Docker API.

Each event is annotated with:

  • Container ID
  • Name
  • Image
  • Labels

When running Elastic Agent 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 Elastic Agent is running as non-root inside the container.

If the Docker daemon is restarted, the mounted socket will become invalid, and metadata will stop working. When this happens, you can do one of the following:

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

Example

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  - 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: false
      # 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"

Configuration settings

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Elastic Agent processors execute before ingest pipelines, which means that they process the raw event data rather than the final event sent to Elasticsearch. For related limitations, refer to What are some limitations of using processors?

Name Required Default Description

host

No

unix:///var/run/docker.sock

Docker socket (UNIX or TCP socket).

ssl

No

SSL configuration to use when connecting to the Docker socket. For a list of available settings, refer to SSL/TLS, specifically the settings under Table 1, “Common configuration options” and Table 2, “Client configuration options”.

match_fields

No

List of fields to match a container ID. At least one of the fields most hold a container ID to get the event enriched.

match_pids

No

["process.pid", "process.parent.pid"]

List of fields that contain process IDs. If the process is running in Docker, the event will be enriched.

match_source

No

true

Whether to match the container ID from a log path present in the log.file.path field.

match_short_id

No

false

Whether to match the container short ID from a log path present in the log.file.path field. This setting allows you to match directory names that have the first 12 characters of the container ID. For example, /var/log/containers/b7e3460e2b21/*.log.

match_source_index

No

4

Index in the source path split by a forward slash (/) to find the container ID. For example, the default, 4, matches the container ID in /var/lib/docker/containers/<container_id>/*.log.

cleanup_timeout

No

60s

Time of inactivity before container metadata is cleaned up and forgotten.

labels.dedot

No

false

Whether to replace dots (.) in labels with underscores (_).