Fluentd
fluent-plugin-kubernetes_metadata_filter, a plugin forThe Kubernetes metadata plugin filter enriches container log records with pod and namespace metadata.
This plugin derives basic metadata about the container that emitted a given log record using the source of the log record. Records from journald provide metadata about the container environment as named fields. Records from JSON files encode metadata about the container in the file name. The initial metadata derived from the source is used to lookup additional metadata about the container's associated pod and namespace (e.g. UUIDs, labels, annotations) when the kubernetes_url is configured. If the plugin cannot authoritatively determine the namespace of the container emitting a log record, it will use an 'orphan' namespace ID in the metadata. This behaviors supports multi-tenant systems that rely on the authenticity of the namespace for proper log isolation.
Requirements
fluent-plugin-kubernetes_metadata_filter | fluentd | ruby |
---|---|---|
>= 2.10.0 | >= v1.10.0 | >= 2.6 |
>= 2.5.0 | >= v1.10.0 | >= 2.5 |
>= 2.0.0 | >= v0.14.20 | >= 2.1 |
< 2.0.0 | >= v0.12.0 | >= 1.9 |
NOTE: For v0.12 version, you should use 1.x.y version. Please send patch into v0.12 branch if you encountered 1.x version's bug.
NOTE: This documentation is for fluent-plugin-kubernetes_metadata_filter-plugin-elasticsearch 2.x or later. For 1.x documentation, please see v0.12 branch.
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. If not specified, environment variablesKUBERNETES_SERVICE_HOST
andKUBERNETES_SERVICE_PORT
will be used if both are present which is typically true when running fluentd in a pod.apiVersion
- API version to use (default:v1
)ca_file
- path to CA file for Kubernetes server certificate validationverify_ssl
- validate SSL certificates (default:true
)client_cert
- path to a client cert file to authenticate to the API serverclient_key
- path to a client key file to authenticate to the API serverbearer_token_file
- path to a file containing the bearer token to use for authenticationtag_to_kubernetes_name_regexp
- the regular expression used to extract kubernetes metadata (pod name, container name, namespace) from the current fluentd tag. This must use named capture groups forcontainer_name
,pod_name
,namespace
, and eitherpod_uuid (/var/log/pods)
ordocker_id (/var/log/containers)
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
)- DEPRECATED
de_dot
- replace dots in labels and annotations with configuredde_dot_separator
, required for Datadog and ElasticSearch 2.x compatibility (default:true
) - DEPRECATED
de_dot_separator
- separator to use ifde_dot
is enabled (default:_
) - DEPRECATED
de_slash
- replace slashes in labels and annotations with configuredde_slash_separator
, required for Datadog compatibility (default:false
) - DEPRECATED
de_slash_separator
- separator to use ifde_slash
is enabled (default:__
) - DEPRECATED
use_journal
- If false, messages are expected to be formatted and tagged as if read by the fluentd in_tail plugin with wildcard filename. If true, messages are expected to be formatted as if read from the systemd journal. TheMESSAGE
field has the full message. TheCONTAINER_NAME
field has the encoded k8s metadata (see below). TheCONTAINER_ID_FULL
field has the full container uuid. This requires docker to use the--log-driver=journald
log driver. If unset (the default), the plugin will use theCONTAINER_NAME
andCONTAINER_ID_FULL
fields if available, otherwise, will use the tag in thetag_to_kubernetes_name_regexp
format. container_name_to_kubernetes_regexp
- The regular expression used to extract the k8s metadata encoded in the journalCONTAINER_NAME
field default: See code- This corresponds to the definition in the source
annotation_match
- Array of regular expressions matching annotation field names. Matched annotations are added to a log record.allow_orphans
- Modify the namespace and namespace id to the values oforphaned_namespace_name
andorphaned_namespace_id
when true (default:true
)orphaned_namespace_name
- The namespace to associate with records where the namespace can not be determined (default:.orphaned
)orphaned_namespace_id
- The namespace id to associate with records where the namespace can not be determined (default:orphaned
)lookup_from_k8s_field
- If the fieldkubernetes
is present, lookup the metadata from the given subfields such askubernetes.namespace_name
,kubernetes.pod_name
, etc. This allows you to avoid having to pass in metadata to lookup in an explicitly formatted tag name or in an explicitly formattedCONTAINER_NAME
value. For example, setkubernetes.namespace_name
,kubernetes.pod_name
,kubernetes.container_name
, anddocker.id
in the record, and the filter will fill in the rest. (default:true
)ssl_partial_chain
- ifca_file
is for an intermediate CA, or otherwise we do not have the root CA and want to trust the intermediate CA certs we do have, set this totrue
- this corresponds to theopenssl s_client -partial_chain
flag andX509_V_FLAG_PARTIAL_CHAIN
(default:false
)skip_labels
- Skip all label fields from the metadata.skip_container_metadata
- Skip some of the container data of the metadata. The metadata will not contain the container_image and container_image_id fields.skip_master_url
- Skip the master_url field from the metadata.skip_namespace_metadata
- Skip the namespace_id field from the metadata. The fetch_namespace_metadata function will be skipped. The plugin will be faster and cpu consumption will be less.watch_retry_interval
- The time interval in seconds for retry backoffs when watch connections fail. (default:10
)
Reading from the JSON formatted log files with in_tail
and wildcard filenames while respecting the CRI-o log format with the same config you need the fluent-plugin "multi-format-parser":
fluent-gem install fluent-plugin-multi-format-parser
The config block could look like this:
<source>
@type tail
path /var/log/containers/*.log
pos_file fluentd-docker.pos
read_from_head true
tag kubernetes.*
<parse>
@type multi_format
<pattern>
format json
time_key time
time_type string
time_format "%Y-%m-%dT%H:%M:%S.%NZ"
keep_time_key false
</pattern>
<pattern>
format regexp
expression /^(?<time>.+) (?<stream>stdout|stderr)( (?<logtag>.))? (?<log>.*)$/
time_format '%Y-%m-%dT%H:%M:%S.%N%:z'
keep_time_key false
</pattern>
</parse>
</source>
<filter kubernetes.var.log.containers.**.log>
@type kubernetes_metadata
</filter>
<match **>
@type stdout
</match>
Reading from the systemd journal (requires the fluentd fluent-plugin-systemd
and systemd-journal
plugins, and requires docker to use the --log-driver=journald
log driver):
<source>
@type systemd
path /run/log/journal
pos_file journal.pos
tag journal
read_from_head true
</source>
# probably want to use something like fluent-plugin-rewrite-tag-filter to
# retag entries from k8s
<match journal>
@type rewrite_tag_filter
rewriterule1 CONTAINER_NAME ^k8s_ kubernetes.journal.container
...
</match>
<filter kubernetes.**>
@type kubernetes_metadata
use_journal true
</filter>
<match **>
@type stdout
</match>
Environment variables for Kubernetes
If the name of the Kubernetes node the plugin is running on is set as
an environment variable with the name K8S_NODE_NAME
, it will reduce cache
misses and needless calls to the Kubernetes API.
In the Kubernetes container definition, this is easily accomplished by:
env:
- name: K8S_NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
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 named /var/log/containers/fabric8-console-controller-98rqc_default_fabric8-console-container-df14e0d5ae4c07284fa636d739c8fc2e6b52bc344658de7d3f08c36a2e804115.log
:
{
"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",
"pod_id": "c76927af-f563-11e4-b32d-54ee7527188d",
"pod_ip": "172.17.0.8",
"container_name": "fabric8-console-container",
"namespace_name": "default",
"namespace_id": "23437884-8e08-4d95-850b-e94378c9b2fd",
"namespace_annotations": {
"fabric8.io/git-commit": "5e1116f63df0bac2a80bdae2ebdc563577bbdf3c"
},
"namespace_labels": {
"product_version": "v1.0.0"
},
"labels": {
"component": "fabric8Console"
}
}
}
If using journal input, from docker configured with --log-driver=journald
, the input looks like the journalctl -o export
format:
# The stream identification is encoded into the PRIORITY field as an
# integer: 6, or github.com/coreos/go-systemd/journal.Info, marks stdout,
# while 3, or github.com/coreos/go-systemd/journal.Err, marks stderr.
PRIORITY=6
CONTAINER_ID=b6cbb6e73c0a
CONTAINER_ID_FULL=b6cbb6e73c0ad63ab820e4baa97cdc77cec729930e38a714826764ac0491341a
CONTAINER_NAME=k8s_registry.a49f5318_docker-registry-1-hhoj0_default_ae3a9bdc-1f66-11e6-80a2-fa163e2fff3a_799e4035
MESSAGE=172.17.0.1 - - [21/May/2016:16:52:05 +0000] "GET /healthz HTTP/1.1" 200 0 "" "Go-http-client/1.1"
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Test it (
GEM_HOME=vendor bundle install; GEM_HOME=vendor bundle exec rake test
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request
Copyright
Copyright (c) 2015 jimmidyson