fluent-plugin-kubernetes_metadata_filter, a plugin for Fluentd

Installation

gem install fluent-plugin-kubernetes_metadata_filter

Configuration

Configuration options for fluent.conf are:

• kubernetes_url - URL to the API server. Set this to retrieve further kubernetes metadata for logs from kubernetes API server
• apiVersion - API version to use (default: v1)
• ca_file - path to CA file for Kubernetes server certificate validation
• verify_ssl - validate SSL certificates (default: true)
• client_cert - path to a client cert file to authenticate to the API server
• client_key - path to a client key file to authenticate to the API server
• bearer_token_file - path to a file containing the bearer token to use for authentication
• tag_to_kubernetes_name_regexp - the regular expression used to extract kubernetes metadata (pod name, container name, namespace) from the current fluentd tag. This must used named capture groups for container_name, pod_name & namespace (default: \.(?<pod_name>[^\._]+)_(?<namespace>[^_]+)_(?<container_name>.+)-(?<docker_id>[a-z0-9]{64})\.log$</pod>))
• cache_size - size of the cache of Kubernetes metadata to reduce requests to the API server (default: 1000)
• cache_ttl - TTL in seconds of each cached element. Set to negative value to disable TTL eviction (default: 3600 - 1 hour)
• watch - set up a watch on pods on the API server for updates to metadata (default: true)
• merge_json_log - merge logs in JSON format as top level keys (default: true)

<source>
  type tail
  path /var/log/containers/*.log
  pos_file fluentd-docker.pos
  time_format %Y-%m-%dT%H:%M:%S
  tag kubernetes.*
  format json
  read_from_head true
</source>

<filter kubernetes.var.lib.docker.containers.*.*.log>
  type kubernetes_metadata
</filter>

<match **>
  type stdout
</match>

Example input/output

Kubernetes creates symlinks to Docker log files in /var/log/containers/*.log. Docker logs in JSON format.

Assuming following inputs are coming from a log file:

{
  "log": "2015/05/05 19:54:41 \n",
  "stream": "stderr",
  "time": "2015-05-05T19:54:41.240447294Z"
}

Then output becomes as belows

{
  "log": "2015/05/05 19:54:41 \n",
  "stream": "stderr",
  "docker": {
    "id": "df14e0d5ae4c07284fa636d739c8fc2e6b52bc344658de7d3f08c36a2e804115",
  }
  "kubernetes": {
    "host": "jimmi-redhat.localnet",
    "pod_name":"fabric8-console-controller-98rqc",
    "container_name": "fabric8-console-container",
    "namespace": "default",
    "uid": "c76927af-f563-11e4-b32d-54ee7527188d",
    "labels": {
      "component": "fabric8Console"
    }
  }
}

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Copyright

Copyright (c) 2015 jimmidyson