Add Fluentd as a Receiver
You can use Elasticsearch, Kafka and Fluentd as log receivers in KubeSphere. This tutorial demonstrates:
- How to deploy Fluentd as a Deployment and create the corresponding Service and ConfigMap.
- How to add Fluentd as a log receiver to receive logs sent from Fluent Bit and then output to stdout.
- How to verify if Fluentd receives logs successfully.
You need a user granted a role including the permission of Cluster Management. For example, you can log in to the console as
admindirectly or create a new role with the permission and assign it to a user.
Before adding a log receiver, you need to enable any of the
auditingcomponents. For more information, see Enable Pluggable Components.
loggingis enabled as an example in this tutorial.
Step 1: Deploy Fluentd as a Deployment
Usually, Fluentd is deployed as a DaemonSet in Kubernetes to collect container logs on each node. KubeSphere chooses Fluent Bit because of its low memory footprint. Besides, Fluentd features numerous output plugins. Hence, KubeSphere chooses to deploy Fluentd as a Deployment to forward logs it receives from Fluent Bit to more destinations such as S3, MongoDB, Cassandra, MySQL, syslog and Splunk.
Run the following commands:
- The following commands create the Fluentd Deployment, Service, and ConfigMap in the
defaultnamespace and add a filter to the Fluentd ConfigMap to exclude logs from the
defaultnamespace to avoid Fluent Bit and Fluentd loop log collections.
- Change the namespace if you want to deploy Fluentd into a different namespace.
cat <<EOF | kubectl apply -f - apiVersion: v1 kind: ConfigMap metadata: name: fluentd-config namespace: default data: fluent.conf: |- # Receive logs sent from Fluent Bit on port 24224 <source> @type forward port 24224 </source> # Because this will send logs Fluentd received to stdout, # to avoid Fluent Bit and Fluentd loop logs collection, # add a filter here to avoid sending logs from the default namespace to stdout again <filter **> @type grep <exclude> key $.kubernetes.namespace_name pattern /^default$/ </exclude> </filter> # Send received logs to stdout for demo/test purpose only # Various output plugins are supported to output logs to S3, MongoDB, Cassandra, MySQL, syslog, Splunk, etc. <match **> @type stdout </match> --- apiVersion: apps/v1 kind: Deployment metadata: labels: app: fluentd name: fluentd namespace: default spec: replicas: 1 selector: matchLabels: app: fluentd template: metadata: labels: app: fluentd spec: containers: - image: fluentd:v1.9.1-1.0 imagePullPolicy: IfNotPresent name: fluentd ports: - containerPort: 24224 name: forward protocol: TCP - containerPort: 5140 name: syslog protocol: TCP volumeMounts: - mountPath: /fluentd/etc name: config readOnly: true volumes: - configMap: defaultMode: 420 name: fluentd-config name: config --- apiVersion: v1 kind: Service metadata: labels: app: fluentd name: fluentd namespace: default spec: ports: - name: forward port: 24224 protocol: TCP targetPort: forward selector: app: fluentd sessionAffinity: None type: ClusterIP EOF
Step 2: Add Fluentd as a Log Receiver
Log in to KubeSphere as
admin. Click Platform in the upper-left corner and select Cluster Management.
NoteIf you have enabled the multi-cluster feature, you can select a specific cluster.
On the Cluster Management page, go to Log Receivers in Cluster Settings.
Click Add Log Receiver and choose Fluentd.
Provide the Fluentd service address and port number.
Fluentd will appear in the receiver list on the Log Receivers page, the status of which is Collecting.
Step 3: Verify Fluentd is Receiving Logs Sent from Fluent Bit
Click Application Workloads on the Cluster Management page.
Select Workloads and then select the
defaultproject on the Deployments tab.
Click the fluentd item and then select the fluentd-xxxxxxxxx-xxxxx Pod.
Click the fluentd container.
On the fluentd container page, select the Container Logs tab.
You can see logs begin to scroll up continuously.
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