Forwarding logs to external third-party logging systems

By default, the logging subsystem sends container and infrastructure logs to the default internal Elasticsearch log store defined in the ClusterLogging custom resource. However, it does not send audit logs to the internal store because it does not provide secure storage. If this default configuration meets your needs, you do not need to configure the Cluster Log Forwarder.

To send logs to other log aggregators, you use the OKD Cluster Log Forwarder. This API enables you to send container, infrastructure, and audit logs to specific endpoints within or outside your cluster. In addition, you can send different types of logs to various systems so that various individuals can access each type. You can also enable Transport Layer Security (TLS) support to send logs securely, as required by your organization.

When you forward logs externally, the logging subsystem creates or modifies a Fluentd config map to send logs using your desired protocols. You are responsible for configuring the protocol on the external log aggregator.

About forwarding logs to third-party systems

To send logs to specific endpoints inside and outside your OKD cluster, you specify a combination of outputs and pipelines in a ClusterLogForwarder custom resource (CR). You can also use inputs to forward the application logs associated with a specific project to an endpoint. Authentication is provided by a Kubernetes Secret object.

output

The destination for log data that you define, or where you want the logs sent. An output can be one of the following types:

• elasticsearch. An external Elasticsearch instance. The elasticsearch output can use a TLS connection.

• fluentdForward. An external log aggregation solution that supports Fluentd. This option uses the Fluentd forward protocols. The fluentForward output can use a TCP or TLS connection and supports shared-key authentication by providing a shared_key field in a secret. Shared-key authentication can be used with or without TLS.

• syslog. An external log aggregation solution that supports the syslog RFC3164 or RFC5424 protocols. The syslog output can use a UDP, TCP, or TLS connection.

• cloudwatch. Amazon CloudWatch, a monitoring and log storage service hosted by Amazon Web Services (AWS).

• loki. Loki, a horizontally scalable, highly available, multi-tenant log aggregation system.

• kafka. A Kafka broker. The kafka output can use a TCP or TLS connection.

• default. The internal OKD Elasticsearch instance. You are not required to configure the default output. If you do configure a default output, you receive an error message because the default output is reserved for the Red Hat OpenShift Logging Operator.

pipeline

Defines simple routing from one log type to one or more outputs, or which logs you want to send. The log types are one of the following:

• application. Container logs generated by user applications running in the cluster, except infrastructure container applications.

• infrastructure. Container logs from pods that run in the openshift*, kube*, or default projects and journal logs sourced from node file system.

• audit. Audit logs generated by the node audit system, auditd, Kubernetes API server, OpenShift API server, and OVN network.

You can add labels to outbound log messages by using key:value pairs in the pipeline. For example, you might add a label to messages that are forwarded to other data centers or label the logs by type. Labels that are added to objects are also forwarded with the log message.

input

Forwards the application logs associated with a specific project to a pipeline.

In the pipeline, you define which log types to forward using an inputRef parameter and where to forward the logs to using an outputRef parameter.

Secret

A key:value map that contains confidential data such as user credentials.

Note the following:

• If a ClusterLogForwarder CR object exists, logs are not forwarded to the default Elasticsearch instance, unless there is a pipeline with the default output.

• By default, the logging subsystem sends container and infrastructure logs to the default internal Elasticsearch log store defined in the ClusterLogging custom resource. However, it does not send audit logs to the internal store because it does not provide secure storage. If this default configuration meets your needs, do not configure the Log Forwarding API.

• If you do not define a pipeline for a log type, the logs of the undefined types are dropped. For example, if you specify a pipeline for the application and audit types, but do not specify a pipeline for the infrastructure type, infrastructure logs are dropped.

• You can use multiple types of outputs in the ClusterLogForwarder custom resource (CR) to send logs to servers that support different protocols.

• The internal OKD Elasticsearch instance does not provide secure storage for audit logs. We recommend you ensure that the system to which you forward audit logs is compliant with your organizational and governmental regulations and is properly secured. The logging subsystem does not comply with those regulations.

The following example forwards the audit logs to a secure external Elasticsearch instance, the infrastructure logs to an insecure external Elasticsearch instance, the application logs to a Kafka broker, and the application logs from the my-apps-logs project to the internal Elasticsearch instance.

Sample log forwarding outputs and pipelines

apiVersion: "logging.openshift.io/v1"
kind: ClusterLogForwarder
metadata:
  name: instance (1)
  namespace: openshift-logging (2)
spec:
  outputs:
   - name: elasticsearch-secure (3)
     type: "elasticsearch"
     url: https://elasticsearch.secure.com:9200
     secret:
        name: elasticsearch
   - name: elasticsearch-insecure (4)
     type: "elasticsearch"
     url: http://elasticsearch.insecure.com:9200
   - name: kafka-app (5)
     type: "kafka"
     url: tls://kafka.secure.com:9093/app-topic
  inputs: (6)
   - name: my-app-logs
     application:
        namespaces:
        - my-project
  pipelines:
   - name: audit-logs (7)
     inputRefs:
      - audit
     outputRefs:
      - elasticsearch-secure
      - default
     parse: json (8)
     labels:
       secure: "true" (9)
       datacenter: "east"
   - name: infrastructure-logs (10)
     inputRefs:
      - infrastructure
     outputRefs:
      - elasticsearch-insecure
     labels:
       datacenter: "west"
   - name: my-app (11)
     inputRefs:
      - my-app-logs
     outputRefs:
      - default
   - inputRefs: (12)
      - application
     outputRefs:
      - kafka-app
     labels:
       datacenter: "south"

Fluentd log handling when the external log aggregator is unavailable

If your external logging aggregator becomes unavailable and cannot receive logs, Fluentd continues to collect logs and stores them in a buffer. When the log aggregator becomes available, log forwarding resumes, including the buffered logs. If the buffer fills completely, Fluentd stops collecting logs. OKD rotates the logs and deletes them. You cannot adjust the buffer size or add a persistent volume claim (PVC) to the Fluentd daemon set or pods.

Supported Authorization Keys

Common key types are provided here. Some output types support additional specialized keys, documented with the output-specific configuration field. All secret keys are optional. Enable the security features you want by setting the relevant keys. You are responsible for creating and maintaining any additional configurations that external destinations might require, such as keys and secrets, service accounts, port openings, or global proxy configuration. Open Shift Logging will not attempt to verify a mismatch between authorization combinations.

Transport Layer Security (TLS)

Using a TLS URL (‘http://…​‘ or ‘ssl://…​’) without a Secret enables basic TLS server-side authentication. Additional TLS features are enabled by including a Secret and setting the following optional fields:

• tls.crt: (string) File name containing a client certificate. Enables mutual authentication. Requires tls.key.

• tls.key: (string) File name containing the private key to unlock the client certificate. Requires tls.crt.

• passphrase: (string) Passphrase to decode an encoded TLS private key. Requires tls.key.

• ca-bundle.crt: (string) File name of a customer CA for server authentication.

Username and Password

• username: (string) Authentication user name. Requires password.

• password: (string) Authentication password. Requires username.

Simple Authentication Security Layer (SASL)

• sasl.enable (boolean) Explicitly enable or disable SASL. If missing, SASL is automatically enabled when any of the other sasl. keys are set.

• sasl.mechanisms: (array) List of allowed SASL mechanism names. If missing or empty, the system defaults are used.

• sasl.allow-insecure: (boolean) Allow mechanisms that send clear-text passwords. Defaults to false.

Creating a Secret

You can create a secret in the directory that contains your certificate and key files by using the following command:

$ oc create secret generic -n openshift-logging <my-secret> \
 --from-file=tls.key=<your_key_file>
 --from-file=tls.crt=<your_crd_file>
 --from-file=ca-bundle.crt=<your_bundle_file>
 --from-literal=username=<your_username>
 --from-literal=password=<your_password>

Forwarding JSON logs from containers in the same pod to separate indices

You can forward structured logs from different containers within the same pod to different indices. To use this feature, you must configure the pipeline with multi-container support and annotate the pods. Logs are written to indices with a prefix of app-. It is recommended that Elasticsearch be configured with aliases to accommodate this.

Prerequisites

• Logging subsystem for Red Hat OpenShift: 5.5

Procedure

1. Create or edit a YAML file that defines the ClusterLogForwarder CR object:

   apiVersion: "logging.openshift.io/v1"
   kind: ClusterLogForwarder
   metadata:
     name: instance
     namespace: openshift-logging
   spec:
     outputDefaults:
       elasticsearch:
         enableStructuredContainerLogs: true (1)
     pipelines:
     - inputRefs:
       - application
       name: application-logs
       outputRefs:
       - default
       parse: json

   1	Enables multi-container outputs.

2. Create or edit a YAML file that defines the Pod CR object:

       apiVersion: v1
       kind: Pod
       metadata:
         annotations:
           containerType.logging.openshift.io/heavy: heavy (1)
           containerType.logging.openshift.io/low: low
       spec:
         containers:
         - name: heavy (2)
           image: heavyimage
         - name: low
           image: lowimage

   1	Format: containerType.logging.openshift.io/<container-name>: <index>
   2	Annotation names must match container names

Additional Resources

Kubernetes Annotations

Supported log data output types in OpenShift Logging 5.1

Red Hat OpenShift Logging 5.1 provides the following output types and protocols for sending log data to target log collectors.

Red Hat tests each of the combinations shown in the following table. However, you should be able to send log data to a wider range target log collectors that ingest these protocols.

Supported log data output types in OpenShift Logging 5.2

Red Hat OpenShift Logging 5.2 provides the following output types and protocols for sending log data to target log collectors.

Red Hat tests each of the combinations shown in the following table. However, you should be able to send log data to a wider range target log collectors that ingest these protocols.

Forwarding logs to an external Elasticsearch instance

You can optionally forward logs to an external Elasticsearch instance in addition to, or instead of, the internal OKD Elasticsearch instance. You are responsible for configuring the external log aggregator to receive log data from OKD.

To configure log forwarding to an external Elasticsearch instance, you must create a ClusterLogForwarder custom resource (CR) with an output to that instance, and a pipeline that uses the output. The external Elasticsearch output can use the HTTP (insecure) or HTTPS (secure HTTP) connection.

To forward logs to both an external and the internal Elasticsearch instance, create outputs and pipelines to the external instance and a pipeline that uses the default output to forward logs to the internal instance. You do not need to create a default output. If you do configure a default output, you receive an error message because the default output is reserved for the Red Hat OpenShift Logging Operator.

Prerequisites

• You must have a logging server that is configured to receive the logging data using the specified protocol or format.

Procedure

1. Create or edit a YAML file that defines the ClusterLogForwarder CR object:

   apiVersion: "logging.openshift.io/v1"
   kind: ClusterLogForwarder
   metadata:
     name: instance (1)
     namespace: openshift-logging (2)
   spec:
     outputs:
      - name: elasticsearch-insecure (3)
        type: "elasticsearch" (4)
        url: http://elasticsearch.insecure.com:9200 (5)
      - name: elasticsearch-secure
        type: "elasticsearch"
        url: https://elasticsearch.secure.com:9200 (6)
        secret:
           name: es-secret (7)
     pipelines:
      - name: application-logs (8)
        inputRefs: (9)
        - application
        - audit
        outputRefs:
        - elasticsearch-secure (10)
        - default (11)
        parse: json (12)
        labels:
          myLabel: "myValue" (13)
      - name: infrastructure-audit-logs (14)
        inputRefs:
        - infrastructure
        outputRefs:
        - elasticsearch-insecure
        labels:
          logs: "audit-infra"

   1	The name of the ClusterLogForwarder CR must be instance.
   2	The namespace for the ClusterLogForwarder CR must be openshift-logging.
   3	Specify a name for the output.
   4	Specify the elasticsearch type.
   5	Specify the URL and port of the external Elasticsearch instance as a valid absolute URL. You can use the http (insecure) or https (secure HTTP) protocol. If the cluster-wide proxy using the CIDR annotation is enabled, the output must be a server name or FQDN, not an IP Address.
   6	For a secure connection, you can specify an https or http URL that you authenticate by specifying a secret.
   7	For an https prefix, specify the name of the secret required by the endpoint for TLS communication. The secret must exist in the openshift-logging project, and must have keys of: tls.crt, tls.key, and ca-bundle.crt that point to the respective certificates that they represent. Otherwise, for http and https prefixes, you can specify a secret that contains a username and password. For more information, see the following “Example: Setting secret that contains a username and password.”
   8	Optional: Specify a name for the pipeline.
   9	Specify which log types to forward by using the pipeline: application, infrastructure, or audit.
   10	Specify the name of the output to use when forwarding logs with this pipeline.
   11	Optional: Specify the default output to send the logs to the internal Elasticsearch instance.
   12	Optional: Specify whether to forward structured JSON log entries as JSON objects in the structured field. The log entry must contain valid structured JSON; otherwise, OpenShift Logging removes the structured field and instead sends the log entry to the default index, app-00000x.
   13	Optional: String. One or more labels to add to the logs.
   14	Optional: Configure multiple outputs to forward logs to other external log aggregators of any supported type: A name to describe the pipeline. The inputRefs is the log type to forward by using the pipeline: application, infrastructure, or audit. The outputRefs is the name of the output to use. Optional: String. One or more labels to add to the logs.

2. Create the CR object:

   $ oc create -f <file-name>.yaml

Example: Setting a secret that contains a username and password

You can use a secret that contains a username and password to authenticate a secure connection to an external Elasticsearch instance.

For example, if you cannot use mutual TLS (mTLS) keys because a third party operates the Elasticsearch instance, you can use HTTP or HTTPS and set a secret that contains the username and password.

1. Create a Secret YAML file similar to the following example. Use base64-encoded values for the username and password fields. The secret type is opaque by default.

   apiVersion: v1
   kind: Secret
   metadata:
     name: openshift-test-secret
   data:
     username: dGVzdHVzZXJuYW1lCg==
     password: dGVzdHBhc3N3b3JkCg==

2. Create the secret:

   $ oc create secret -n openshift-logging openshift-test-secret.yaml

3. Specify the name of the secret in the ClusterLogForwarder CR:

   kind: ClusterLogForwarder
   metadata:
     name: instance
     namespace: openshift-logging
   spec:
     outputs:
      - name: elasticsearch
        type: "elasticsearch"
        url: https://elasticsearch.secure.com:9200
        secret:
           name: openshift-test-secret

   In the value of the url field, the prefix can be http or https.

4. Create the CR object:

   $ oc create -f <file-name>.yaml

Forwarding logs using the Fluentd forward protocol

You can use the Fluentd forward protocol to send a copy of your logs to an external log aggregator that is configured to accept the protocol instead of, or in addition to, the default Elasticsearch log store. You are responsible for configuring the external log aggregator to receive the logs from OKD.

To configure log forwarding using the forward protocol, you must create a ClusterLogForwarder custom resource (CR) with one or more outputs to the Fluentd servers, and pipelines that use those outputs. The Fluentd output can use a TCP (insecure) or TLS (secure TCP) connection.

Prerequisites

• You must have a logging server that is configured to receive the logging data using the specified protocol or format.

Procedure

1. Create or edit a YAML file that defines the ClusterLogForwarder CR object:

   apiVersion: logging.openshift.io/v1
   kind: ClusterLogForwarder
   metadata:
     name: instance (1)
     namespace: openshift-logging (2)
   spec:
     outputs:
      - name: fluentd-server-secure (3)
        type: fluentdForward (4)
        url: 'tls://fluentdserver.security.example.com:24224' (5)
        secret: (6)
           name: fluentd-secret
      - name: fluentd-server-insecure
        type: fluentdForward
        url: 'tcp://fluentdserver.home.example.com:24224'
     pipelines:
      - name: forward-to-fluentd-secure (7)
        inputRefs:  (8)
        - application
        - audit
        outputRefs:
        - fluentd-server-secure (9)
        - default (10)
        parse: json (11)
        labels:
          clusterId: "C1234" (12)
      - name: forward-to-fluentd-insecure (13)
        inputRefs:
        - infrastructure
        outputRefs:
        - fluentd-server-insecure
        labels:
          clusterId: "C1234"

   1	The name of the ClusterLogForwarder CR must be instance.
   2	The namespace for the ClusterLogForwarder CR must be openshift-logging.
   3	Specify a name for the output.
   4	Specify the fluentdForward type.
   5	Specify the URL and port of the external Fluentd instance as a valid absolute URL. You can use the tcp (insecure) or tls (secure TCP) protocol. If the cluster-wide proxy using the CIDR annotation is enabled, the output must be a server name or FQDN, not an IP address.
   6	If using a tls prefix, you must specify the name of the secret required by the endpoint for TLS communication. The secret must exist in the openshift-logging project, and must have keys of: tls.crt, tls.key, and ca-bundle.crt that point to the respective certificates that they represent. Otherwise, for http and https prefixes, you can specify a secret that contains a username and password. For more information, see the following “Example: Setting secret that contains a username and password.”
   7	Optional: Specify a name for the pipeline.
   8	Specify which log types to forward by using the pipeline: application, infrastructure, or audit.
   9	Specify the name of the output to use when forwarding logs with this pipeline.
   10	Optional: Specify the default output to forward logs to the internal Elasticsearch instance.
   11	Optional: Specify whether to forward structured JSON log entries as JSON objects in the structured field. The log entry must contain valid structured JSON; otherwise, OpenShift Logging removes the structured field and instead sends the log entry to the default index, app-00000x.
   12	Optional: String. One or more labels to add to the logs.
   13	Optional: Configure multiple outputs to forward logs to other external log aggregators of any supported type: A name to describe the pipeline. The inputRefs is the log type to forward by using the pipeline: application, infrastructure, or audit. The outputRefs is the name of the output to use. Optional: String. One or more labels to add to the logs.

2. Create the CR object:

   $ oc create -f <file-name>.yaml

Enabling nanosecond precision for Logstash to ingest data from fluentd

For Logstash to ingest log data from fluentd, you must enable nanosecond precision in the Logstash configuration file.

Procedure

• In the Logstash configuration file, set nanosecond_precision to true.

Example Logstash configuration file

input { tcp { codec => fluent { nanosecond_precision => true } port => 24114 } }
filter { }
output { stdout { codec => rubydebug } }

Forwarding logs using the syslog protocol

You can use the syslog RFC3164 or RFC5424 protocol to send a copy of your logs to an external log aggregator that is configured to accept the protocol instead of, or in addition to, the default Elasticsearch log store. You are responsible for configuring the external log aggregator, such as a syslog server, to receive the logs from OKD.

To configure log forwarding using the syslog protocol, you must create a ClusterLogForwarder custom resource (CR) with one or more outputs to the syslog servers, and pipelines that use those outputs. The syslog output can use a UDP, TCP, or TLS connection.

Prerequisites

• You must have a logging server that is configured to receive the logging data using the specified protocol or format.

Procedure

1. Create or edit a YAML file that defines the ClusterLogForwarder CR object:

   apiVersion: logging.openshift.io/v1
   kind: ClusterLogForwarder
   metadata:
     name: instance (1)
     namespace: openshift-logging (2)
   spec:
     outputs:
      - name: rsyslog-east (3)
        type: syslog (4)
        syslog: (5)
          facility: local0
          rfc: RFC3164
          payloadKey: message
          severity: informational
        url: 'tls://rsyslogserver.east.example.com:514' (6)
        secret: (7)
           name: syslog-secret
      - name: rsyslog-west
        type: syslog
        syslog:
         appName: myapp
         facility: user
         msgID: mymsg
         procID: myproc
         rfc: RFC5424
         severity: debug
        url: 'udp://rsyslogserver.west.example.com:514'
     pipelines:
      - name: syslog-east (8)
        inputRefs: (9)
        - audit
        - application
        outputRefs: (10)
        - rsyslog-east
        - default (11)
        parse: json (12)
        labels:
          secure: "true" (13)
          syslog: "east"
      - name: syslog-west (14)
        inputRefs:
        - infrastructure
        outputRefs:
        - rsyslog-west
        - default
        labels:
          syslog: "west"

   1	The name of the ClusterLogForwarder CR must be instance.
   2	The namespace for the ClusterLogForwarder CR must be openshift-logging.
   3	Specify a name for the output.
   4	Specify the syslog type.
   5	Optional: Specify the syslog parameters, listed below.
   6	Specify the URL and port of the external syslog instance. You can use the udp (insecure), tcp (insecure) or tls (secure TCP) protocol. If the cluster-wide proxy using the CIDR annotation is enabled, the output must be a server name or FQDN, not an IP address.
   7	If using a tls prefix, you must specify the name of the secret required by the endpoint for TLS communication. The secret must exist in the openshift-logging project, and must have keys of: tls.crt, tls.key, and ca-bundle.crt that point to the respective certificates that they represent.
   8	Optional: Specify a name for the pipeline.
   9	Specify which log types to forward by using the pipeline: application, infrastructure, or audit.
   10	Specify the name of the output to use when forwarding logs with this pipeline.
   11	Optional: Specify the default output to forward logs to the internal Elasticsearch instance.
   12	Optional: Specify whether to forward structured JSON log entries as JSON objects in the structured field. The log entry must contain valid structured JSON; otherwise, OpenShift Logging removes the structured field and instead sends the log entry to the default index, app-00000x.
   13	Optional: String. One or more labels to add to the logs. Quote values like “true” so they are recognized as string values, not as a boolean.
   14	Optional: Configure multiple outputs to forward logs to other external log aggregators of any supported type: A name to describe the pipeline. The inputRefs is the log type to forward by using the pipeline: application, infrastructure, or audit. The outputRefs is the name of the output to use. Optional: String. One or more labels to add to the logs.

2. Create the CR object:

   $ oc create -f <file-name>.yaml

Adding log source information to message output

You can add namespace_name, pod_name, and container_name elements to the message field of the record by adding the AddLogSource field to your ClusterLogForwarder custom resource (CR).

  spec:
    outputs:
    - name: syslogout
      syslog:
        addLogSource: true
        facility: user
        payloadKey: message
        rfc: RFC3164
        severity: debug
        tag: mytag
      type: syslog
      url: tls://syslog-receiver.openshift-logging.svc:24224
    pipelines:
    - inputRefs:
      - application
      name: test-app
      outputRefs:
      - syslogout

Example syslog message output without AddLogSource

<15>1 2020-11-15T17:06:14+00:00 fluentd-9hkb4 mytag - - -  {"msgcontent"=>"Message Contents", "timestamp"=>"2020-11-15 17:06:09", "tag_key"=>"rec_tag", "index"=>56}

Example syslog message output with AddLogSource

<15>1 2020-11-16T10:49:37+00:00 crc-j55b9-master-0 mytag - - -  namespace_name=clo-test-6327,pod_name=log-generator-ff9746c49-qxm7l,container_name=log-generator,message={"msgcontent":"My life is my message", "timestamp":"2020-11-16 10:49:36", "tag_key":"rec_tag", "index":76}

Syslog parameters

You can configure the following for the syslog outputs. For more information, see the syslog RFC3164 or RFC5424 RFC.

• facility: The syslog facility. The value can be a decimal integer or a case-insensitive keyword:

  • 0 or kern for kernel messages

  • 1 or user for user-level messages, the default.

  • 2 or mail for the mail system

  • 3 or daemon for system daemons

  • 4 or auth for security/authentication messages

  • 5 or syslog for messages generated internally by syslogd

  • 6 or lpr for the line printer subsystem

  • 7 or news for the network news subsystem

  • 8 or uucp for the UUCP subsystem

  • 9 or cron for the clock daemon

  • 10 or authpriv for security authentication messages

  • 11 or ftp for the FTP daemon

  • 12 or ntp for the NTP subsystem

  • 13 or security for the syslog audit log

  • 14 or console for the syslog alert log

  • 15 or solaris-cron for the scheduling daemon

  • 16–23 or local0 – local7 for locally used facilities

• Optional: payloadKey: The record field to use as payload for the syslog message.

  Configuring the payloadKey parameter prevents other parameters from being forwarded to the syslog.

• rfc: The RFC to be used for sending logs using syslog. The default is RFC5424.

• severity: The syslog severity to set on outgoing syslog records. The value can be a decimal integer or a case-insensitive keyword:

  • 0 or Emergency for messages indicating the system is unusable

  • 1 or Alert for messages indicating action must be taken immediately

  • 2 or Critical for messages indicating critical conditions

  • 3 or Error for messages indicating error conditions

  • 4 or Warning for messages indicating warning conditions

  • 5 or Notice for messages indicating normal but significant conditions

  • 6 or Informational for messages indicating informational messages

  • 7 or Debug for messages indicating debug-level messages, the default

• tag: Tag specifies a record field to use as a tag on the syslog message.

• trimPrefix: Remove the specified prefix from the tag.

Additional RFC5424 syslog parameters

The following parameters apply to RFC5424:

• appName: The APP-NAME is a free-text string that identifies the application that sent the log. Must be specified for RFC5424.

• msgID: The MSGID is a free-text string that identifies the type of message. Must be specified for RFC5424.

• procID: The PROCID is a free-text string. A change in the value indicates a discontinuity in syslog reporting. Must be specified for RFC5424.

Forwarding logs to Amazon CloudWatch

You can forward logs to Amazon CloudWatch, a monitoring and log storage service hosted by Amazon Web Services (AWS). You can forward logs to CloudWatch in addition to, or instead of, the default log store.

To configure log forwarding to CloudWatch, you must create a ClusterLogForwarder custom resource (CR) with an output for CloudWatch, and a pipeline that uses the output.

Procedure

1. Create a Secret YAML file that uses the aws_access_key_id and aws_secret_access_key fields to specify your base64-encoded AWS credentials. For example:

   apiVersion: v1
   kind: Secret
   metadata:
     name: cw-secret
     namespace: openshift-logging
   data:
     aws_access_key_id: QUtJQUlPU0ZPRE5ON0VYQU1QTEUK
     aws_secret_access_key: d0phbHJYVXRuRkVNSS9LN01ERU5HL2JQeFJmaUNZRVhBTVBMRUtFWQo=

2. Create the secret. For example:

   $ oc apply -f cw-secret.yaml

3. Create or edit a YAML file that defines the ClusterLogForwarder CR object. In the file, specify the name of the secret. For example:

   apiVersion: "logging.openshift.io/v1"
   kind: ClusterLogForwarder
   metadata:
     name: instance (1)
     namespace: openshift-logging (2)
   spec:
     outputs:
      - name: cw (3)
        type: cloudwatch (4)
        cloudwatch:
          groupBy: logType (5)
          groupPrefix: <group prefix> (6)
          region: us-east-2 (7)
        secret:
           name: cw-secret (8)
     pipelines:
       - name: infra-logs (9)
         inputRefs: (10)
           - infrastructure
           - audit
           - application
         outputRefs:
           - cw (11)

   1	The name of the ClusterLogForwarder CR must be instance.
   2	The namespace for the ClusterLogForwarder CR must be openshift-logging.
   3	Specify a name for the output.
   4	Specify the cloudwatch type.
   5	Optional: Specify how to group the logs: logType creates log groups for each log type namespaceName creates a log group for each application name space. It also creates separate log groups for infrastructure and audit logs. namespaceUUID creates a new log groups for each application namespace UUID. It also creates separate log groups for infrastructure and audit logs.
   6	Optional: Specify a string to replace the default infrastructureName prefix in the names of the log groups.
   7	Specify the AWS region.
   8	Specify the name of the secret that contains your AWS credentials.
   9	Optional: Specify a name for the pipeline.
   10	Specify which log types to forward by using the pipeline: application, infrastructure, or audit.
   11	Specify the name of the output to use when forwarding logs with this pipeline.

4. Create the CR object:

   $ oc create -f <file-name>.yaml

Example: Using ClusterLogForwarder with Amazon CloudWatch

Here, you see an example ClusterLogForwarder custom resource (CR) and the log data that it outputs to Amazon CloudWatch.

Suppose that you are running an OKD cluster named mycluster. The following command returns the cluster’s infrastructureName, which you will use to compose aws commands later on:

$ oc get Infrastructure/cluster -ojson | jq .status.infrastructureName
"mycluster-7977k"

To generate log data for this example, you run a busybox pod in a namespace called app. The busybox pod writes a message to stdout every three seconds:

$ oc run busybox --image=busybox -- sh -c 'while true; do echo "My life is my message"; sleep 3; done'
$ oc logs -f busybox
My life is my message
My life is my message
My life is my message
...

You can look up the UUID of the app namespace where the busybox pod runs:

$ oc get ns/app -ojson | jq .metadata.uid
"794e1e1a-b9f5-4958-a190-e76a9b53d7bf"

In your ClusterLogForwarder custom resource (CR), you configure the infrastructure, audit, and application log types as inputs to the all-logs pipeline. You also connect this pipeline to cw output, which forwards the logs to a CloudWatch instance in the us-east-2 region:

apiVersion: "logging.openshift.io/v1"
kind: ClusterLogForwarder
metadata:
  name: instance
  namespace: openshift-logging
spec:
  outputs:
   - name: cw
     type: cloudwatch
     cloudwatch:
       groupBy: logType
       region: us-east-2
     secret:
        name: cw-secret
  pipelines:
    - name: all-logs
      inputRefs:
        - infrastructure
        - audit
        - application
      outputRefs:
        - cw

Each region in CloudWatch contains three levels of objects:

• log group

  • log stream

    • log event

With groupBy: logType in the ClusterLogForwarding CR, the three log types in the inputRefs produce three log groups in Amazon Cloudwatch:

$ aws --output json logs describe-log-groups | jq .logGroups[].logGroupName
"mycluster-7977k.application"
"mycluster-7977k.audit"
"mycluster-7977k.infrastructure"

Each of the log groups contains log streams:

$ aws --output json logs describe-log-streams --log-group-name mycluster-7977k.application | jq .logStreams[].logStreamName
"kubernetes.var.log.containers.busybox_app_busybox-da085893053e20beddd6747acdbaf98e77c37718f85a7f6a4facf09ca195ad76.log"

$ aws --output json logs describe-log-streams --log-group-name mycluster-7977k.audit | jq .logStreams[].logStreamName
"ip-10-0-131-228.us-east-2.compute.internal.k8s-audit.log"
"ip-10-0-131-228.us-east-2.compute.internal.linux-audit.log"
"ip-10-0-131-228.us-east-2.compute.internal.openshift-audit.log"
...

$ aws --output json logs describe-log-streams --log-group-name mycluster-7977k.infrastructure | jq .logStreams[].logStreamName
"ip-10-0-131-228.us-east-2.compute.internal.kubernetes.var.log.containers.apiserver-69f9fd9b58-zqzw5_openshift-oauth-apiserver_oauth-apiserver-453c5c4ee026fe20a6139ba6b1cdd1bed25989c905bf5ac5ca211b7cbb5c3d7b.log"
"ip-10-0-131-228.us-east-2.compute.internal.kubernetes.var.log.containers.apiserver-797774f7c5-lftrx_openshift-apiserver_openshift-apiserver-ce51532df7d4e4d5f21c4f4be05f6575b93196336be0027067fd7d93d70f66a4.log"
"ip-10-0-131-228.us-east-2.compute.internal.kubernetes.var.log.containers.apiserver-797774f7c5-lftrx_openshift-apiserver_openshift-apiserver-check-endpoints-82a9096b5931b5c3b1d6dc4b66113252da4a6472c9fff48623baee761911a9ef.log"
...

Each log stream contains log events. To see a log event from the busybox Pod, you specify its log stream from the application log group:

$ aws logs get-log-events --log-group-name mycluster-7977k.application --log-stream-name kubernetes.var.log.containers.busybox_app_busybox-da085893053e20beddd6747acdbaf98e77c37718f85a7f6a4facf09ca195ad76.log
{
    "events": [
        {
            "timestamp": 1629422704178,
            "message": "{\"docker\":{\"container_id\":\"da085893053e20beddd6747acdbaf98e77c37718f85a7f6a4facf09ca195ad76\"},\"kubernetes\":{\"container_name\":\"busybox\",\"namespace_name\":\"app\",\"pod_name\":\"busybox\",\"container_image\":\"docker.io/library/busybox:latest\",\"container_image_id\":\"docker.io/library/busybox@sha256:0f354ec1728d9ff32edcd7d1b8bbdfc798277ad36120dc3dc683be44524c8b60\",\"pod_id\":\"870be234-90a3-4258-b73f-4f4d6e2777c7\",\"host\":\"ip-10-0-216-3.us-east-2.compute.internal\",\"labels\":{\"run\":\"busybox\"},\"master_url\":\"https://kubernetes.default.svc\",\"namespace_id\":\"794e1e1a-b9f5-4958-a190-e76a9b53d7bf\",\"namespace_labels\":{\"kubernetes_io/metadata_name\":\"app\"}},\"message\":\"My life is my message\",\"level\":\"unknown\",\"hostname\":\"ip-10-0-216-3.us-east-2.compute.internal\",\"pipeline_metadata\":{\"collector\":{\"ipaddr4\":\"10.0.216.3\",\"inputname\":\"fluent-plugin-systemd\",\"name\":\"fluentd\",\"received_at\":\"2021-08-20T01:25:08.085760+00:00\",\"version\":\"1.7.4 1.6.0\"}},\"@timestamp\":\"2021-08-20T01:25:04.178986+00:00\",\"viaq_index_name\":\"app-write\",\"viaq_msg_id\":\"NWRjZmUyMWQtZjgzNC00MjI4LTk3MjMtNTk3NmY3ZjU4NDk1\",\"log_type\":\"application\",\"time\":\"2021-08-20T01:25:04+00:00\"}",
            "ingestionTime": 1629422744016
        },
...

Example: Customizing the prefix in log group names

In the log group names, you can replace the default infrastructureName prefix, mycluster-7977k, with an arbitrary string like demo-group-prefix. To make this change, you update the groupPrefix field in the ClusterLogForwarding CR:

cloudwatch:
    groupBy: logType
    groupPrefix: demo-group-prefix
    region: us-east-2

The value of groupPrefix replaces the default infrastructureName prefix:

$ aws --output json logs describe-log-groups | jq .logGroups[].logGroupName
"demo-group-prefix.application"
"demo-group-prefix.audit"
"demo-group-prefix.infrastructure"

Example: Naming log groups after application namespace names

For each application namespace in your cluster, you can create a log group in CloudWatch whose name is based on the name of the application namespace.

If you delete an application namespace object and create a new one that has the same name, CloudWatch continues using the same log group as before.

If you consider successive application namespace objects that have the same name as equivalent to each other, use the approach described in this example. Otherwise, if you need to distinguish the resulting log groups from each other, see the following “Naming log groups for application namespace UUIDs” section instead.

To create application log groups whose names are based on the names of the application namespaces, you set the value of the groupBy field to namespaceName in the ClusterLogForwarder CR:

cloudwatch:
    groupBy: namespaceName
    region: us-east-2

Setting groupBy to namespaceName affects the application log group only. It does not affect the audit and infrastructure log groups.

In Amazon Cloudwatch, the namespace name appears at the end of each log group name. Because there is a single application namespace, “app”, the following output shows a new mycluster-7977k.app log group instead of mycluster-7977k.application:

$ aws --output json logs describe-log-groups | jq .logGroups[].logGroupName
"mycluster-7977k.app"
"mycluster-7977k.audit"
"mycluster-7977k.infrastructure"

If the cluster in this example had contained multiple application namespaces, the output would show multiple log groups, one for each namespace.

The groupBy field affects the application log group only. It does not affect the audit and infrastructure log groups.

Example: Naming log groups after application namespace UUIDs

For each application namespace in your cluster, you can create a log group in CloudWatch whose name is based on the UUID of the application namespace.

If you delete an application namespace object and create a new one, CloudWatch creates a new log group.

If you consider successive application namespace objects with the same name as different from each other, use the approach described in this example. Otherwise, see the preceding “Example: Naming log groups for application namespace names” section instead.

To name log groups after application namespace UUIDs, you set the value of the groupBy field to namespaceUUID in the ClusterLogForwarder CR:

cloudwatch:
    groupBy: namespaceUUID
    region: us-east-2

In Amazon Cloudwatch, the namespace UUID appears at the end of each log group name. Because there is a single application namespace, “app”, the following output shows a new mycluster-7977k.794e1e1a-b9f5-4958-a190-e76a9b53d7bf log group instead of mycluster-7977k.application:

$ aws --output json logs describe-log-groups | jq .logGroups[].logGroupName
"mycluster-7977k.794e1e1a-b9f5-4958-a190-e76a9b53d7bf" // uid of the "app" namespace
"mycluster-7977k.audit"
"mycluster-7977k.infrastructure"

The groupBy field affects the application log group only. It does not affect the audit and infrastructure log groups.

Forwarding logs to Amazon CloudWatch from STS enabled clusters

For clusters with AWS Security Token Service (STS) enabled, you can create an AWS service account manually or create a credentials request using the Cloud Credential Operator(CCO) utility ccoctl.

Prerequisites

• Logging subsystem for Red Hat OpenShift: 5.5 and later

Creating an AWS credentials request

1. Create a CredentialsRequest Custom Resource YAML using the template below:

   CloudWatch Credentials Request Template

   apiVersion: cloudcredential.openshift.io/v1
   kind: CredentialsRequest
   metadata:
     name: <your_role_name>-credrequest
     namespace: openshift-cloud-credential-operator
   spec:
     providerSpec:
       apiVersion: cloudcredential.openshift.io/v1
       kind: AWSProviderSpec
       statementEntries:
         - action:
             - logs:PutLogEvents
             - logs:CreateLogGroup
             - logs:PutRetentionPolicy
             - logs:CreateLogStream
             - logs:DescribeLogGroups
             - logs:DescribeLogStreams
           effect: Allow
           resource: arn:aws:logs:*:*:*
     secretRef:
       name: <your_role_name>
       namespace: openshift-logging
     serviceAccountNames:
       - logcollector

2. Use the ccoctl command to to create a role for AWS using your CredentialsRequest CR. With the CredentialsRequest object, this ccoctl command creates an IAM role with a trust policy that is tied to the specified OIDC identity provider, and a permissions policy that grants permissions to perform operations on CloudWatch resources. This command also creates a YAML configuration file in `/<path_to_ccoctl_output_dir>/manifests/openshift-logging-<your_role_name>-credentials.yaml. This secret file contains the role_arn key/value used during authentication with the AWS IAM identity provider.

   ccoctl aws create-iam-roles \
   --name=<name> \
   --region=<aws_region> \
   --credentials-requests-dir=<path_to_directory_with_list_of_credentials_requests>/credrequests \
   --identity-provider-arn=arn:aws:iam::<aws_account_id>:oidc-provider/<name>-oidc.s3.<aws_region>.amazonaws.com (1)

   1	<name> is the name used to tag your cloud resources and should match the name used during your STS cluster install

3. Apply the secret created:

    oc apply -f output/manifests/openshift-logging-<your_role_name>-credentials.yaml

4. Create or edit a ClusterLogForwarder custom resource:

   apiVersion: "logging.openshift.io/v1"
   kind: ClusterLogForwarder
   metadata:
     name: instance (1)
     namespace: openshift-logging (2)
   spec:
     outputs:
      - name: cw (3)
        type: cloudwatch (4)
        cloudwatch:
          groupBy: logType (5)
          groupPrefix: <group prefix> (6)
          region: us-east-2 (7)
        secret:
           name: <your_role_name> (8)
     pipelines:
       - name: to-cloudwatch (9)
         inputRefs: (10)
           - infrastructure
           - audit
           - application
         outputRefs:
           - cw (11)

   1	The name of the ClusterLogForwarder CR must be instance.
   2	The namespace for the ClusterLogForwarder CR must be openshift-logging.
   3	Specify a name for the output.
   4	Specify the cloudwatch type.
   5	Optional: Specify how to group the logs: logType creates log groups for each log type namespaceName creates a log group for each application name space. Infrastructure and audit logs are unaffected, remaining grouped by logType. namespaceUUID creates a new log groups for each application namespace UUID. It also creates separate log groups for infrastructure and audit logs.
   6	Optional: Specify a string to replace the default infrastructureName prefix in the names of the log groups.
   7	Specify the AWS region.
   8	Specify the name of the secret that contains your AWS credentials.
   9	Optional: Specify a name for the pipeline.
   10	Specify which log types to forward by using the pipeline: application, infrastructure, or audit.
   11	Specify the name of the output to use when forwarding logs with this pipeline.

Additional resources

• AWS STS API Reference

Creating a secret for AWS CloudWatch with an existing AWS role

If you have an existing role for AWS, you can create a secret for AWS with STS using the oc create secret --from-literal command.

oc create secret generic cw-sts-secret -n openshift-logging --from-literal=role_arn=arn:aws:iam::123456789012:role/my-role_with-permissions

Example Secret

apiVersion: v1
kind: Secret
metadata:
  namespace: openshift-logging
  name: my-secret-name
stringData:
  role_arn: arn:aws:iam::123456789012:role/my-role_with-permissions

Forwarding logs to Loki

You can forward logs to an external Loki logging system in addition to, or instead of, the internal default OKD Elasticsearch instance.

To configure log forwarding to Loki, you must create a ClusterLogForwarder custom resource (CR) with an output to Loki, and a pipeline that uses the output. The output to Loki can use the HTTP (insecure) or HTTPS (secure HTTP) connection.

Prerequisites

• You must have a Loki logging system running at the URL you specify with the url field in the CR.

Procedure

1. Create or edit a YAML file that defines the ClusterLogForwarder CR object:

     apiVersion: "logging.openshift.io/v1"
     kind: ClusterLogForwarder
     metadata:
       name: instance (1)
       namespace: openshift-logging (2)
     spec:
       outputs:
        - name: loki-insecure (3)
          type: "loki" (4)
          url: http://loki.insecure.com:3100 (5)
          loki:
             tenantKey: kubernetes.namespace_name
             labelKeys: kubernetes.labels.foo
        - name: loki-secure (6)
          type: "loki"
          url: https://loki.secure.com:3100
          secret:
             name: loki-secret (7)
          loki:
             tenantKey: kubernetes.namespace_name (8)
             labelKeys: kubernetes.labels.foo (9)
       pipelines:
        - name: application-logs (10)
          inputRefs:  (11)
          - application
          - audit
          outputRefs: (12)
          - loki-secure

   1	The name of the ClusterLogForwarder CR must be instance.
   2	The namespace for the ClusterLogForwarder CR must be openshift-logging.
   3	Specify a name for the output.
   4	Specify the type as “loki”.
   5	Specify the URL and port of the Loki system as a valid absolute URL. You can use the http (insecure) or https (secure HTTP) protocol. If the cluster-wide proxy using the CIDR annotation is enabled, the output must be a server name or FQDN, not an IP Address. Loki’s default port for HTTP(S) communication is 3100.
   6	For a secure connection, you can specify an https or http URL that you authenticate by specifying a secret.
   7	For an https prefix, specify the name of the secret required by the endpoint for TLS communication. The secret must exist in the openshift-logging project, and must have keys of: tls.crt, tls.key, and ca-bundle.crt that point to the respective certificates that they represent. Otherwise, for http and https prefixes, you can specify a secret that contains a username and password. For more information, see the following “Example: Setting secret that contains a username and password.”
   8	Optional: Specify a meta-data key field to generate values for the TenantID field in Loki. For example, setting tenantKey: kubernetes.namespacename uses the names of the Kubernetes namespaces as values for tenant IDs in Loki. To see which other log record fields you can specify, see the “Log Record Fields” link in the following “Additional resources” section.
   9	Optional: Specify a list of meta-data field keys to replace the default Loki labels. Loki label names must match the regular expression [a-zA-Z:][a-zA-Z0-9:]*. Illegal characters in meta-data keys are replaced with to form the label name. For example, the kubernetes.labels.foo meta-data key becomes Loki label kubernetes_labels_foo. If you do not set labelKeys, the default value is: [log_type, kubernetes.namespace_name, kubernetes.pod_name, kubernetes_host]. Keep the set of labels small because Loki limits the size and number of labels allowed. See Configuring Loki, limits_config. You can still query based on any log record field using query filters.
   10	Optional: Specify a name for the pipeline.
   11	Specify which log types to forward by using the pipeline: application, infrastructure, or audit.
   12	Specify the name of the output to use when forwarding logs with this pipeline.

   Because Loki requires log streams to be correctly ordered by timestamp, labelKeys always includes the kubernetes_host label set, even if you do not specify it. This inclusion ensures that each stream originates from a single host, which prevents timestamps from becoming disordered due to clock differences on different hosts.

2. Create the CR object:

   $ oc create -f <file-name>.yaml

Troubleshooting Loki “entry out of order” errors

If your Fluentd forwards a large block of messages to a Loki logging system that exceeds the rate limit, Loki to generates “entry out of order” errors. To fix this issue, you update some values in the Loki server configuration file, loki.yaml.

Conditions

• The ClusterLogForwarder custom resource is configured to forward logs to Loki.

• Your system sends a block of messages that is larger than 2 MB to Loki, such as:

  "values":[["1630410392689800468","{\"kind\":\"Event\",\"apiVersion\":\
  .......
  ......
  ......
  ......
  \"received_at\":\"2021-08-31T11:46:32.800278+00:00\",\"version\":\"1.7.4 1.6.0\"}},\"@timestamp\":\"2021-08-31T11:46:32.799692+00:00\",\"viaq_index_name\":\"audit-write\",\"viaq_msg_id\":\"MzFjYjJkZjItNjY0MC00YWU4LWIwMTEtNGNmM2E5ZmViMGU4\",\"log_type\":\"audit\"}"]]}]}

• When you enter oc logs -c fluentd, the Fluentd logs in your OpenShift Logging cluster show the following messages:

  429 Too Many Requests Ingestion rate limit exceeded (limit: 8388608 bytes/sec) while attempting to ingest '2140' lines totaling '3285284' bytes
  429 Too Many Requests Ingestion rate limit exceeded' or '500 Internal Server Error rpc error: code = ResourceExhausted desc = grpc: received message larger than max (5277702 vs. 4194304)'

• When you open the logs on the Loki server, they display entry out of order messages like these:

  ,\nentry with timestamp 2021-08-18 05:58:55.061936 +0000 UTC ignored, reason: 'entry out of order' for stream:
  {fluentd_thread=\"flush_thread_0\", log_type=\"audit\"},\nentry with timestamp 2021-08-18 06:01:18.290229 +0000 UTC ignored, reason: 'entry out of order' for stream: {fluentd_thread="flush_thread_0", log_type="audit"}

Procedure

1. Update the following fields in the loki.yaml configuration file on the Loki server with the values shown here:

   • grpc_server_max_recv_msg_size: 8388608

   • chunk_target_size: 8388608

   • ingestion_rate_mb: 8

   • ingestion_burst_size_mb: 16

2. Apply the changes in loki.yaml to the Loki server.

Example loki.yaml file

auth_enabled: false
server:
  http_listen_port: 3100
  grpc_listen_port: 9096
  grpc_server_max_recv_msg_size: 8388608
ingester:
  wal:
    enabled: true
    dir: /tmp/wal
  lifecycler:
    address: 127.0.0.1
    ring:
      kvstore:
        store: inmemory
      replication_factor: 1
    final_sleep: 0s
  chunk_idle_period: 1h       # Any chunk not receiving new logs in this time will be flushed
  chunk_target_size: 8388608
  max_chunk_age: 1h           # All chunks will be flushed when they hit this age, default is 1h
  chunk_retain_period: 30s    # Must be greater than index read cache TTL if using an index cache (Default index read cache TTL is 5m)
  max_transfer_retries: 0     # Chunk transfers disabled
schema_config:
  configs:
    - from: 2020-10-24
      store: boltdb-shipper
      object_store: filesystem
      schema: v11
      index:
        prefix: index_
        period: 24h
storage_config:
  boltdb_shipper:
    active_index_directory: /tmp/loki/boltdb-shipper-active
    cache_location: /tmp/loki/boltdb-shipper-cache
    cache_ttl: 24h         # Can be increased for faster performance over longer query periods, uses more disk space
    shared_store: filesystem
  filesystem:
    directory: /tmp/loki/chunks
compactor:
  working_directory: /tmp/loki/boltdb-shipper-compactor
  shared_store: filesystem
limits_config:
  reject_old_samples: true
  reject_old_samples_max_age: 12h
  ingestion_rate_mb: 8
  ingestion_burst_size_mb: 16
chunk_store_config:
  max_look_back_period: 0s
table_manager:
  retention_deletes_enabled: false
  retention_period: 0s
ruler:
  storage:
    type: local
    local:
      directory: /tmp/loki/rules
  rule_path: /tmp/loki/rules-temp
  alertmanager_url: http://localhost:9093
  ring:
    kvstore:
      store: inmemory
  enable_api: true

Additional resources

• Configuring Loki

Additional resources

• Log Record Fields.

• Configuring Loki server

Forwarding application logs from specific projects

You can use the Cluster Log Forwarder to send a copy of the application logs from specific projects to an external log aggregator. You can do this in addition to, or instead of, using the default Elasticsearch log store. You must also configure the external log aggregator to receive log data from OKD.

To configure forwarding application logs from a project, you must create a ClusterLogForwarder custom resource (CR) with at least one input from a project, optional outputs for other log aggregators, and pipelines that use those inputs and outputs.

Prerequisites

• You must have a logging server that is configured to receive the logging data using the specified protocol or format.

Procedure

1. Create or edit a YAML file that defines the ClusterLogForwarder CR object:

   apiVersion: logging.openshift.io/v1
   kind: ClusterLogForwarder
   metadata:
     name: instance (1)
     namespace: openshift-logging (2)
   spec:
     outputs:
      - name: fluentd-server-secure (3)
        type: fluentdForward (4)
        url: 'tls://fluentdserver.security.example.com:24224' (5)
        secret: (6)
           name: fluentd-secret
      - name: fluentd-server-insecure
        type: fluentdForward
        url: 'tcp://fluentdserver.home.example.com:24224'
     inputs: (7)
      - name: my-app-logs
        application:
           namespaces:
           - my-project
     pipelines:
      - name: forward-to-fluentd-insecure (8)
        inputRefs: (9)
        - my-app-logs
        outputRefs: (10)
        - fluentd-server-insecure
        parse: json (11)
        labels:
          project: "my-project" (12)
      - name: forward-to-fluentd-secure (13)
        inputRefs:
        - application
        - audit
        - infrastructure
        outputRefs:
        - fluentd-server-secure
        - default
        labels:
          clusterId: "C1234"

   1	The name of the ClusterLogForwarder CR must be instance.
   2	The namespace for the ClusterLogForwarder CR must be openshift-logging.
   3	Specify a name for the output.
   4	Specify the output type: elasticsearch, fluentdForward, syslog, or kafka.
   5	Specify the URL and port of the external log aggregator as a valid absolute URL. If the cluster-wide proxy using the CIDR annotation is enabled, the output must be a server name or FQDN, not an IP address.
   6	If using a tls prefix, you must specify the name of the secret required by the endpoint for TLS communication. The secret must exist in the openshift-logging project and have tls.crt, tls.key, and ca-bundle.crt keys that each point to the certificates they represent.
   7	Configuration for an input to filter application logs from the specified projects.
   8	Configuration for a pipeline to use the input to send project application logs to an external Fluentd instance.
   9	The my-app-logs input.
   10	The name of the output to use.
   11	Optional: Specify whether to forward structured JSON log entries as JSON objects in the structured field. The log entry must contain valid structured JSON; otherwise, OpenShift Logging removes the structured field and instead sends the log entry to the default index, app-00000x.
   12	Optional: String. One or more labels to add to the logs.
   13	Configuration for a pipeline to send logs to other log aggregators. Optional: Specify a name for the pipeline. Specify which log types to forward by using the pipeline: application, infrastructure, or audit. Specify the name of the output to use when forwarding logs with this pipeline. Optional: Specify the default output to forward logs to the internal Elasticsearch instance. Optional: String. One or more labels to add to the logs.

2. Create the CR object:

   $ oc create -f <file-name>.yaml

Forwarding application logs from specific pods

As a cluster administrator, you can use Kubernetes pod labels to gather log data from specific pods and forward it to a log collector.

Suppose that you have an application composed of pods running alongside other pods in various namespaces. If those pods have labels that identify the application, you can gather and output their log data to a specific log collector.

To specify the pod labels, you use one or more matchLabels key-value pairs. If you specify multiple key-value pairs, the pods must match all of them to be selected.

Procedure

1. Create or edit a YAML file that defines the ClusterLogForwarder CR object. In the file, specify the pod labels using simple equality-based selectors under inputs[].name.application.selector.matchLabels, as shown in the following example.

   Example ClusterLogForwarder CR YAML file

   apiVersion: logging.openshift.io/v1
   kind: ClusterLogForwarder
   metadata:
     name: instance (1)
     namespace: openshift-logging (2)
   spec:
     pipelines:
       - inputRefs: [ myAppLogData ] (3)
         outputRefs: [ default ] (4)
         parse: json (5)
     inputs: (6)
       - name: myAppLogData
         application:
           selector:
             matchLabels: (7)
               environment: production
               app: nginx
           namespaces: (8)
           - app1
           - app2
     outputs: (9)
       - default
       ...

   1	The name of the ClusterLogForwarder CR must be instance.
   2	The namespace for the ClusterLogForwarder CR must be openshift-logging.
   3	Specify one or more comma-separated values from inputs[].name.
   4	Specify one or more comma-separated values from outputs[].
   5	Optional: Specify whether to forward structured JSON log entries as JSON objects in the structured field. The log entry must contain valid structured JSON; otherwise, OpenShift Logging removes the structured field and instead sends the log entry to the default index, app-00000x.
   6	Define a unique inputs[].name for each application that has a unique set of pod labels.
   7	Specify the key-value pairs of pod labels whose log data you want to gather. You must specify both a key and value, not just a key. To be selected, the pods must match all the key-value pairs.
   8	Optional: Specify one or more namespaces.
   9	Specify one or more outputs to forward your log data to. The optional default output shown here sends log data to the internal Elasticsearch instance.

2. Optional: To restrict the gathering of log data to specific namespaces, use inputs[].name.application.namespaces, as shown in the preceding example.

3. Optional: You can send log data from additional applications that have different pod labels to the same pipeline.

   1. For each unique combination of pod labels, create an additional inputs[].name section similar to the one shown.

   2. Update the selectors to match the pod labels of this application.

   3. Add the new inputs[].name value to inputRefs. For example:

      - inputRefs: [ myAppLogData, myOtherAppLogData ]

4. Create the CR object:

   $ oc create -f <file-name>.yaml

Additional resources

• For more information on matchLabels in Kubernetes, see Resources that support set-based requirements.

Collecting OVN network policy audit logs

You can collect the OVN network policy audit logs from the /var/log/ovn/acl-audit-log.log file on OVN-Kubernetes pods and forward them to logging servers.

Prerequisites

• You are using OKD version 4.8 or later.

• You are using Cluster Logging 5.2 or later.

• You have already set up a ClusterLogForwarder custom resource (CR) object.

• The OKD cluster is configured for OVN-Kubernetes network policy audit logging. See the following “Additional resources” section.

Procedure

1. Create or edit a YAML file that defines the ClusterLogForwarder CR object as described in other topics on forwarding logs to third-party systems.

2. In the YAML file, add the audit log type to the inputRefs element in a pipeline. For example:

     pipelines:
      - name: audit-logs
        inputRefs:
         - audit (1)
        outputRefs:
         - secure-logging-server (2)

   1	Specify audit as one of the log types to input.
   2	Specify the output that connects to your logging server.

3. Recreate the updated CR object:

   $ oc create -f <file-name>.yaml

Verification

Verify that audit log entries from the nodes that you are monitoring are present among the log data gathered by the logging server.

Find an original audit log entry in /var/log/ovn/acl-audit-log.log and compare it with the corresponding log entry on the logging server.

For example, an original log entry in /var/log/ovn/acl-audit-log.log might look like this:

2021-07-06T08:26:58.687Z|00004|acl_log(ovn_pinctrl0)|INFO|name="verify-audit-
logging_deny-all", verdict=drop, severity=alert:
icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:12,dl_dst=0a:58:0a:81:02:14,nw_src=10
.129.2.18,nw_dst=10.129.2.20,nw_tos=0,nw_ecn=0,nw_ttl=64,icmp_type=8,icmp_code=0

And the corresponding OVN audit log entry you find on the logging server might look like this:

{
  "@timestamp" : "2021-07-06T08:26:58..687000+00:00",
  "hostname":"ip.abc.iternal",
  "level":"info",
  "message" : "2021-07-06T08:26:58.687Z|00004|acl_log(ovn_pinctrl0)|INFO|name=\"verify-audit-logging_deny-all\", verdict=drop, severity=alert: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:12,dl_dst=0a:58:0a:81:02:14,nw_src=10.129.2.18,nw_dst=10.129.2.20,nw_tos=0,nw_ecn=0,nw_ttl=64,icmp_type=8,icmp_code=0"
}

Where:

• @timestamp is the timestamp of the log entry.

• hostname is the node from which the log originated.

• level is the log entry.

• message is the original audit log message.

Troubleshooting

1. Verify that your OKD cluster meets all the prerequisites.

2. Verify that you have completed the procedure.

3. Verify that the nodes generating OVN logs are enabled and have /var/log/ovn/acl-audit-log.log files.

4. Check the Fluentd pod logs for issues.

Additional resources

• Network policy audit logging

Troubleshooting log forwarding

When you create a ClusterLogForwarder custom resource (CR), if the Red Hat OpenShift Logging Operator does not redeploy the Fluentd pods automatically, you can delete the Fluentd pods to force them to redeploy.

Prerequisites

• You have created a ClusterLogForwarder custom resource (CR) object.

Procedure

• Delete the Fluentd pods to force them to redeploy.

  $ oc delete pod --selector logging-infra=collector