Service Artem is running…

At the time of writing, EKS Fargate does not support a driver log for recording to CloudWatch. The only option is to use Sidecar

Let’s create a ConfigMap, in which we indicate the name of the EKS cluster, region and namespace:

kubectl create configmap cluster-info \
--from-literal=cluster.name=YOUR_EKS_CLUSTER_NAME \
--from-literal=logs.region=YOUR_EKS_CLUSTER_REGION -n KUBERNETES_NAMESPACE

Next, let’s create a service account and a ConfigMap with a configuration file for Fluentd. To do this, copy the text below and save it as “fluentd.yaml”

apiVersion: v1
kind: ServiceAccount
metadata:
  name: fluentd
  namespace: {{NAMESPACE}}
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: fluentd-role
rules:
  - apiGroups: [""]
    resources:
      - namespaces
      - pods
      - pods/logs
    verbs: ["get", "list", "watch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: fluentd-role-binding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: fluentd-role
subjects:
  - kind: ServiceAccount
    name: fluentd
    namespace: {{NAMESPACE}}
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: fluentd-config
  namespace: {{NAMESPACE}}
  labels:
    k8s-app: fluentd-cloudwatch
data:
  fluent.conf: |
    @include containers.conf
 
    <match fluent.**>
      @type null
    </match>
  containers.conf: |
    <source>
      @type tail
      @id in_tail_container_logs
      @label @containers
      path /var/log/application.log
      pos_file /var/log/fluentd-containers.log.pos
      tag *
      read_from_head true
      <parse>
        @type none
        time_format %Y-%m-%dT%H:%M:%S.%NZ
      </parse>
    </source>
 
    <label @containers>
      <filter **>
        @type kubernetes_metadata
        @id filter_kube_metadata
      </filter>
 
      <filter **>
        @type record_transformer
        @id filter_containers_stream_transformer
        <record>
          stream_name "#{ENV.fetch('HOSTNAME')}"
        </record>
      </filter>
 
      <filter **>
        @type concat
        key log
        multiline_start_regexp /^\S/
        separator ""
        flush_interval 5
        timeout_label @NORMAL
      </filter>
 
      <match **>
        @type relabel
        @label @NORMAL
      </match>
    </label>
 
    <label @NORMAL>
      <match **>
        @type cloudwatch_logs
        @id out_cloudwatch_logs_containers
        region "#{ENV.fetch('REGION')}"
        log_group_name "/aws/containerinsights/#{ENV.fetch('CLUSTER_NAME')}/application"
        log_stream_name_key stream_name
        remove_log_stream_name_key true
        auto_create_stream true
        <buffer>
          flush_interval 5
          chunk_limit_size 2m
          queued_chunks_limit_size 32
          retry_forever true
        </buffer>
      </match>
    </label>

And apply it:

curl fluentd.yaml | sed "s/{{NAMESPACE}}/default/" | kubectl apply -f -

Where “default” is the name of the required namespace

An example of a sidecar deployment:

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: testapp
  name: testapp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: testapp
  strategy: {}
  template:
    metadata:
      labels:
        app: testapp
    spec:
      serviceAccountName: fluentd
      terminationGracePeriodSeconds: 30
      initContainers:
        - name: copy-fluentd-config
          image: busybox
          command: ['sh', '-c', 'cp /config-volume/..data/* /fluentd/etc']
          volumeMounts:
            - name: config-volume
              mountPath: /config-volume
            - name: fluentdconf
              mountPath: /fluentd/etc
      containers:
      - image: alpine:3.10
        name: alpine
        command: ["/bin/sh"]
        args: ["-c", "while true; do echo hello 2>&1 | tee -a /var/log/application.log; sleep 10;done"]
        volumeMounts:
        - name: fluentdconf
          mountPath: /fluentd/etc
        - name: varlog
          mountPath: /var/log
      - image: fluent/fluentd-kubernetes-daemonset:v1.7.3-debian-cloudwatch-1.0
        name: fluentd-cloudwatch
        env:
          - name: REGION
            valueFrom:
              configMapKeyRef:
                name: cluster-info
                key: logs.region
          - name: CLUSTER_NAME
            valueFrom:
              configMapKeyRef:
                name: cluster-info
                key: cluster.name
          - name: AWS_ACCESS_KEY_ID
            value: "XXXXXXXXXXXXXXX"
          - name: "AWS_SECRET_ACCESS_KEY"
            value: "YYYYYYYYYYYYYYY"
        resources:
          limits:
            memory: 400Mi
          requests:
            cpu: 100m
            memory: 200Mi
        volumeMounts:
          - name: config-volume
            mountPath: /config-volume
          - name: fluentdconf
            mountPath: /fluentd/etc
          - name: varlog
            mountPath: /var/log
      volumes:
        - name: config-volume
          configMap:
            name: fluentd-config
        - name: fluentdconf
          emptyDir: {}
        - name: varlog
          emptyDir: {}

In this deployment, the variables are set to “AWS_ACCESS_KEY_ID” and “AWS_SECRET_ACCESS_KEY“, since at the moment there are endpoints for IAM roles only for services: EC2, ECS Fargate and Lambda. For avoid this you can use OpenID Connect provider for EKS.