***************************************** Kubernetes Metadata Module (mmkubernetes) ***************************************** =========================== =========================================================================== **Module Name:**  **mmkubernetes** **Author:** `Tomáš Heinrich` `Rich Megginson` =========================== =========================================================================== Purpose ======= This module is used to add `Kubernetes ` metadata to log messages logged by containers running in Kubernetes. It will add the namespace uuid, pod uuid, pod and namespace labels and annotations, and other metadata associated with the pod and namespace. .. note:: This **only** works with log files in `/var/log/containers/*.log` (docker `--log-driver=json-file`, or CRI-O log files), or with journald entries with message properties `CONTAINER_NAME` and `CONTAINER_ID_FULL` (docker `--log-driver=journald`), and when the application running inside the container writes logs to `stdout`/`stderr`. This **does not** currently work with other log drivers. For json-file and CRI-O logs, you must use the `imfile` module with the `addmetadata="on"` parameter, and the filename must match the liblognorm rules specified by the `filenamerules` (:ref:`filenamerules`) or `filenamerulebase` (:ref:`filenamerulebase`) parameter values. For journald logs, there must be a message property `CONTAINER_NAME` which matches the liblognorm rules specified by the `containerrules` (:ref:`containerrules`) or `containerrulebase` (:ref:`containerrulebase`) parameter values. The record must also have the message property `CONTAINER_ID_FULL`. This module is implemented via the output module interface. This means that mmkubernetes should be called just like an action. After it has been called, there will be two new message properties: `kubernetes` and `docker`. There will be subfields of each one for the various metadata items: `$!kubernetes!namespace_name` `$!kubernetes!labels!this-is-my-label`, etc. There is currently only 1 docker subfield: `$!docker!container_id`. See https://github.com/ViaQ/elasticsearch-templates/blob/master/namespaces/kubernetes.yml and https://github.com/ViaQ/elasticsearch-templates/blob/master/namespaces/docker.yml for more details. Configuration Parameters ======================== .. note:: Parameter names are case-insensitive. Module Parameters and Action Parameters --------------------------------------- .. _kubernetesurl: KubernetesURL ^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "https://kubernetes.default.svc.cluster.local:443", "no", "none" The URL of the Kubernetes API server. Example: `https://localhost:8443`. .. _mmkubernetes-tls.cacert: tls.cacert ^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "none", "no", "none" Full path and file name of file containing the CA cert of the Kubernetes API server cert issuer. Example: `/etc/rsyslog.d/mmk8s-ca.crt`. This parameter is not mandatory if using an `http` scheme instead of `https` in `kubernetesurl`, or if using `allowunsignedcerts="yes"`. .. _mmkubernetes-tls.mycert: tls.mycert ^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "none", "no", "none" This is the full path and file name of the file containing the client cert for doing client cert auth against Kubernetes. This file is in PEM format. For example: `/etc/rsyslog.d/k8s-client-cert.pem` .. _mmkubernetes-tls.myprivkey: tls.myprivkey ^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "none", "no", "none" This is the full path and file name of the file containing the private key corresponding to the cert `tls.mycert` used for doing client cert auth against Kubernetes. This file is in PEM format, and must be unencrypted, so take care to secure it properly. For example: `/etc/rsyslog.d/k8s-client-key.pem` .. _tokenfile: tokenfile ^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "none", "no", "none" The file containing the token to use to authenticate to the Kubernetes API server. One of `tokenfile` or `token` is required if Kubernetes is configured with access control. Example: `/etc/rsyslog.d/mmk8s.token` .. _token: token ^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "none", "no", "none" The token to use to authenticate to the Kubernetes API server. One of `token` or `tokenfile` is required if Kubernetes is configured with access control. Example: `UxMU46ptoEWOSqLNa1bFmH` .. _annotation_match: annotation_match ^^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "array", "none", "no", "none" By default no pod or namespace annotations will be added to the messages. This parameter is an array of patterns to match the keys of the `annotations` field in the pod and namespace metadata to include in the `$!kubernetes!annotations` (for pod annotations) or the `$!kubernetes!namespace_annotations` (for namespace annotations) message properties. Example: `["k8s.*master","k8s.*node"]` .. _srcmetadatapath: srcmetadatapath ^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "$!metadata!filename", "no", "none" When reading json-file logs, with `imfile` and `addmetadata="on"`, this is the property where the filename is stored. .. _dstmetadatapath: dstmetadatapath ^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "$!", "no", "none" This is the where the `kubernetes` and `docker` properties will be written. By default, the module will add `$!kubernetes` and `$!docker`. .. _allowunsignedcerts: allowunsignedcerts ^^^^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "boolean", "off", "no", "none" If `"on"`, this will set the curl `CURLOPT_SSL_VERIFYPEER` option to `0`. You are strongly discouraged to set this to `"on"`. It is primarily useful only for debugging or testing. .. _skipverifyhost: skipverifyhost ^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "boolean", "off", "no", "none" If `"on"`, this will set the curl `CURLOPT_SSL_VERIFYHOST` option to `0`. You are strongly discouraged to set this to `"on"`. It is primarily useful only for debugging or testing. .. _de_dot: de_dot ^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "boolean", "on", "no", "none" When processing labels and annotations, if this parameter is set to `"on"`, the key strings will have their `.` characters replaced with the string specified by the `de_dot_separator` parameter. .. _de_dot_separator: de_dot_separator ^^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "_", "no", "none" When processing labels and annotations, if the `de_dot` parameter is set to `"on"`, the key strings will have their `.` characters replaced with the string specified by the string value of this parameter. .. _filenamerules: filenamerules ^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "SEE BELOW", "no", "none" .. note:: This directive is not supported with liblognorm 2.0.2 and earlier. When processing json-file logs, these are the lognorm rules to use to match the filename and extract metadata. The default value is:: rule=:/var/log/containers/%pod_name:char-to:_%_%namespace_name:char-to:_%_%contai\ ner_name_and_id:char-to:.%.log .. note:: In the above rules, the slashes ``\`` ending each line indicate line wrapping - they are not part of the rule. .. _filenamerulebase: filenamerulebase ^^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "/etc/rsyslog.d/k8s_filename.rulebase", "no", "none" When processing json-file logs, this is the rulebase used to match the filename and extract metadata. For the actual rules, see :ref:`filenamerules`. .. _containerrules: containerrules ^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "SEE BELOW", "no", "none" .. note:: This directive is not supported with liblognorm 2.0.2 and earlier. For journald logs, there must be a message property `CONTAINER_NAME` which has a value matching these rules specified by this parameter. The default value is:: rule=:%k8s_prefix:char-to:_%_%container_name:char-to:.%.%container_hash:char-to:\ _%_%pod_name:char-to:_%_%namespace_name:char-to:_%_%not_used_1:char-to:_%_%not_u\ sed_2:rest% rule=:%k8s_prefix:char-to:_%_%container_name:char-to:_%_%pod_name:char-to:_%_%na\ mespace_name:char-to:_%_%not_used_1:char-to:_%_%not_used_2:rest% .. note:: In the above rules, the slashes ``\`` ending each line indicate line wrapping - they are not part of the rule. There are two rules because the `container_hash` is optional. .. _containerrulebase: containerrulebase ^^^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "word", "/etc/rsyslog.d/k8s_container_name.rulebase", "no", "none" When processing json-file logs, this is the rulebase used to match the CONTAINER_NAME property value and extract metadata. For the actual rules, see :ref:`containerrules`. .. _mmkubernetes-busyretryinterval: busyretryinterval ^^^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "integer", "5", "no", "none" The number of seconds to wait before retrying operations to the Kubernetes API server after receiving a `429 Busy` response. The default `"5"` means that the module will retry the connection every `5` seconds. Records processed during this time will _not_ have any additional metadata associated with them, so you will need to handle cases where some of your records have all of the metadata and some do not. If you want to have rsyslog suspend the plugin until the Kubernetes API server is available, set `busyretryinterval` to `"0"`. This will cause the plugin to return an error to rsyslog. .. _mmkubernetes-sslpartialchain: sslpartialchain ^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "boolean", "off", "no", "none" This option is only available if rsyslog was built with support for OpenSSL and only if the `X509_V_FLAG_PARTIAL_CHAIN` flag is available. If you attempt to set this parameter on other platforms, you will get an `INFO` level log message. This was done so that you could use the same configuration on different platforms. If `"on"`, this will set the OpenSSL certificate store flag `X509_V_FLAG_PARTIAL_CHAIN`. This will allow you to verify the Kubernetes API server cert with only an intermediate CA cert in your local trust store, rather than having to have the entire intermediate CA + root CA chain in your local trust store. See also `man s_client` - the `-partial_chain` flag. If you get errors like this, you probably need to set `sslpartialchain="on"`: .. code-block:: none rsyslogd: mmkubernetes: failed to connect to [https://...url...] - 60:Peer certificate cannot be authenticated with given CA certificates .. _mmkubernetes-cacheexpireinterval: cacheexpireinterval ^^^^^^^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "integer", "-1", "no", "none" This parameter allows you to expire entries from the metadata cache. The values are: - -1 (default) - disables metadata cache expiration - 0 - check cache for expired entries before every cache lookup - 1 or higher - the number is a number of seconds - check the cache for expired entries every this many seconds, when processing an entry The cache is only checked if processing a record from Kubernetes. There isn't some sort of housekeeping thread that continually runs cleaning up the cache. When an record from Kubernetes is processed: If `cacheexpireinterval` is -1, then do not check for cache expiration. If `cacheexpireinterval` is 0, then check for cache expiration. If `cacheexpireinterval` is greater than 0, check for cache expiration if the last time we checked was more than this many seconds ago. When cache expiration is checked, it will delete all cache entries which have a ttl less than or equal to the current time. The cache entry ttl is set using the `cacheentryttl`. .. _mmkubernetes-cacheentryttl: cacheentryttl ^^^^^^^^^^^^^ .. csv-table:: :header: "type", "default", "mandatory", "|FmtObsoleteName| directive" :widths: auto :class: parameter-table "integer", "3600", "no", "none" This parameter allows you to set the maximum age (time-to-live, or ttl) of an entry in the metadata cache. The value is in seconds. The default value is `3600` (one hour). When cache expiration is checked, if a cache entry has a ttl less than or equal to the current time, it will be removed from the cache. This option is only used if `cacheexpireinterval` is 0 or greater. This value must be 0 or greater, otherwise, if `cacheexpireinterval` is 0 or greater, you will get an error. .. _mmkubernetes-statistic-counter: Statistic Counter ================= This plugin maintains per-action :doc:`statistics <../rsyslog_statistic_counter>`. The statistic is named "mmkubernetes($kubernetesurl)", where `$kubernetesurl` is the :ref:`kubernetesurl` setting for the action. Parameters are: - **recordseen** - number of messages seen by the action which the action has determined have Kubernetes metadata associated with them - **namespacemetadatasuccess** - the number of times a successful request was made to the Kubernetes API server for namespace metadata. - **namespacemetadatanotfound** - the number of times a request to the Kubernetes API server for namespace metadata was returned with a `404 Not Found` error code - the namespace did not exist at that time. - **namespacemetadatabusy** - the number of times a request to the Kubernetes API server for namespace metadata was returned with a `429 Busy` error code - the server was too busy to send a proper response. - **namespacemetadataerror** - the number of times a request to the Kubernetes API server for namespace metadata was returned with some other error code not handled above. These are typically "hard" errors which require some sort of intervention to fix e.g. Kubernetes server down, credentials incorrect. - **podmetadatasuccess** - the number of times a successful request was made to the Kubernetes API server for pod metadata. - **podmetadatanotfound** - the number of times a request to the Kubernetes API server for pod metadata was returned with a `404 Not Found` error code - the pod did not exist at that time. - **podmetadatabusy** - the number of times a request to the Kubernetes API server for pod metadata was returned with a `429 Busy` error code - the server was too busy to send a proper response. - **podmetadataerror** - the number of times a request to the Kubernetes API server for pod metadata was returned with some other error code not handled above. These are typically "hard" errors which require some sort of intervention to fix e.g. Kubernetes server down, credentials incorrect. - **podcachenumentries** - the number of entries in the pod metadata cache. - **namespacecachenumentries** - the number of entries in the namespace metadata cache. - **podcachehits** - the number of times a requested entry was found in the pod metadata cache. - **namespacecachehits** - the number of times a requested entry was found in the namespace metadata cache. - **podcachemisses** - the number of times a requested entry was not found in the pod metadata cache, and had to be requested from Kubernetes. - **namespacecachemisses** - the number of times a requested entry was not found in the namespace metadata cache, and had to be requested from Kubernetes. Fields ------ These are the fields added from the metadata in the json-file filename, or from the `CONTAINER_NAME` and `CONTAINER_ID_FULL` fields from the `imjournal` input: `$!kubernetes!namespace_name`, `$!kubernetes!pod_name`, `$!kubernetes!container_name`, `$!docker!id`, `$!kubernetes!master_url`. If mmkubernetes can extract the above fields from the input, the following fields will always be present. If they are not present, mmkubernetes failed to look up the namespace or pod in Kubernetes: `$!kubernetes!namespace_id`, `$!kubernetes!pod_id`, `$!kubernetes!creation_timestamp`, `$!kubernetes!host` The following fields may be present, depending on how the namespace and pod are defined in Kubernetes, and depending on the value of the directive `annotation_match`: `$!kubernetes!labels`, `$!kubernetes!annotations`, `$!kubernetes!namespace_labels`, `$!kubernetes!namespace_annotations` More fields may be added in the future. Error Handling -------------- If the plugin encounters a `404 Not Found` in response to a request for namespace or pod metadata, that is, the pod or namespace is missing, the plugin will cache that result, and no metadata will be available for that pod or namespace forever. If the pod or namespace is recreated, you will need to restart rsyslog in order to clear the cache and allow it to find that metadata. If the plugin gets a `429 Busy` response, the plugin will _not_ cache that result, and will _not_ add the metadata to the record. This can happen in very large Kubernetes clusters when you run into the upper limit on the number of concurrent Kubernetes API service connections. You may have to increase that limit. In the meantime, you can control what the plugin does with those records using the :ref:`mmkubernetes-busyretryinterval` setting. If you want to continue to process the records, but with incomplete metadata, set `busyretryinterval` to a non-zero value, which will be the number of seconds after which mmkubernetes will retry the connection. The default value is `5`, so by default, the plugin will retry the connection every `5` seconds. If the `429` error condition in the Kubernetes API server is brief and transient, this means you will have some (hopefully small) number of records without the metadata such as the uuids, labels, and annotations, but your pipeline will not stop. If the `429` error condition in the Kubernetes API server is persistent, it may require Kubernetes API server administrator intervention to address, and you may want to use the `busyretryinterval` value of `"0"`. This will cause the module to return a "hard" error (see below). For other errors, the plugin will assume they are "hard" errors requiring admin intervention, return an error code, and rsyslog will suspend the plugin. Use the :ref:`mmkubernetes-statistic-counter` to monitor for problems getting data from the Kubernetes API service. Example ------- Assuming you have an `imfile` input reading from docker json-file container logs managed by Kubernetes, with `addmetadata="on"` so that mmkubernetes can get the basic necessary Kubernetes metadata from the filename: .. code-block:: none input(type="imfile" file="/var/log/containers/*.log" tag="kubernetes" addmetadata="on") (Add `reopenOnTruncate="on"` if using Docker, not required by CRI-O). and/or an `imjournal` input for docker journald container logs annotated by Kubernetes: .. code-block:: none input(type="imjournal") Then mmkubernetes can be used to annotate log records like this: .. code-block:: none module(load="mmkubernetes") action(type="mmkubernetes") After this, you should have log records with fields described in the `Fields` section above. Credits ------- This work is based on https://github.com/fabric8io/fluent-plugin-kubernetes_metadata_filter and has many of the same features.