Add Docker metadata [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.

Each event is annotated with:

Container ID
Name
Image
Labels

::::{note} When running Filebeat 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 Filebeat 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 Filebeat every time Docker is restarted
Mount the entire /var/run directory (instead of just the socket)

::::

yaml

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: 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"

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) Defaults to true. When true, replaces dots (.) in labels with underscores (_).