Filebeats Getting Logs from Container in K8s

Elastic Stack Beats
1

I have an express server running in k8s which writes its logs to a file:
'/var/lib/docker/containers/analytics-error.log'

I cannot get Filebeat to pick up this file, here is my conf

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-config
  namespace: kube-system
  labels:
    k8s-app: filebeat
data:
  filebeat.yml: |-
    filebeat.config:
      inputs:
        path: ${path.config}/inputs.d/*.yml
        # Reload inputs configs as they change:
        reload.enabled: false
      modules:
        path: ${path.config}/modules.d/*.yml
        # Reload module configs as they change:
        reload.enabled: false
      setup.template.settings:
        index.number_of_shards: 1

    # To enable hints based autodiscover, remove `filebeat.config.inputs` configuration and uncomment this:
    # filebeat.autodiscover:
    #  providers:
    #    - type: kubernetes
    filebeat.inputs:
      - type: log
        paths:
          - /var/lib/docker/containers
        fields_under_root: true
        fields:
          log_type: etp_log

    logging.level: debug
    logging.selectors: ["prospector","harvester"]

    processors:
      - add_host_metadata: ~
      - add_cloud_metadata: ~

    output.logstash:
      enabled: true
      ssl.enabled: true

      hosts: ["logstash.chargepayments.io:8751"]
      ssl.certificate_authorities: ["${path.config}/keys/ca.crt"]
      ssl.certificate: "${path.config}/keys/client.crt"
      ssl.key: "${path.config}/keys/client.key"
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-inputs
  namespace: kube-system
  labels:
    k8s-app: filebeat
data:
  kubernetes.yml: |-
    - type: docker
      containers.ids:
      - "*"
      path: "/var/lib/docker/containers"
      processors:
        - add_kubernetes_metadata:
            in_cluster: true
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: filebeat
  namespace: kube-system
  labels:
    k8s-app: filebeat
spec:
  template:
    metadata:
      labels:
        k8s-app: filebeat
    spec:
      serviceAccountName: filebeat
      terminationGracePeriodSeconds: 30
      containers:
      - name: filebeat
        image: docker.elastic.co/beats/filebeat:7.0.1
        args: [
          "-c", "/etc/filebeat.yml",
          "-e",
        ]
        securityContext:
          runAsUser: 0
          # If using Red Hat OpenShift uncomment this:
          #privileged: true
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 100Mi
        volumeMounts:
        - name: config
          mountPath: /etc/filebeat.yml
          readOnly: true
          subPath: filebeat.yml
        - name: inputs
          mountPath: /usr/share/filebeat/inputs.d
          readOnly: true
        - name: data
          mountPath: /usr/share/filebeat/data
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers
          readOnly: true
        - name: cacert
          mountPath: /usr/share/filebeat/keys/ca.crt
          subPath: ca.crt
        - name: clientcert
          mountPath: /usr/share/filebeat/keys/client.crt
          subPath: client.crt
        - name: clientkey
          mountPath: /usr/share/filebeat/keys/client.key
          subPath: client.key

      volumes:
      - name: config
        configMap:
          defaultMode: 0600
          name: filebeat-config
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers
      - name: inputs
        configMap:
          defaultMode: 0600
          name: filebeat-inputs
      # data folder stores a registry of read status for all files, so we don't send everything again on a Filebeat pod restart
      - name: data
        hostPath:
          path: /var/lib/filebeat-data
          type: DirectoryOrCreate
      - name: cacert
        secret:
          secretName: certs
          items:
          - key: cacert
            path: ca.crt
      - name: clientcert
        secret:
          secretName: certs
          items:
          - key: clientcert
            path: client.crt
      - name: clientkey
        secret:
          secretName: certs
          items:
          - key: clientkey
            path: client.key

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: filebeat
subjects:
- kind: ServiceAccount
  name: filebeat
  namespace: kube-system
roleRef:
  kind: ClusterRole
  name: filebeat
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: filebeat
  labels:
    k8s-app: filebeat
rules:
- apiGroups: ["*"] # "" indicates the core API group
  resources:
  - namespaces
  - pods
  verbs:
  - get
  - watch
  - list
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: filebeat
  namespace: kube-system
  labels:
    k8s-app: filebeat
---
2

Hey @NFhbar
I'm not so familiar with the setup you mentioned, is var/log/container/.. accessible to filebeat?
Have you tried auto discover feature of filebeat? it reads /var/log/container for running containers and based on module used you could probably achieve the same.
https://www.elastic.co/guide/en/beats/filebeat/current/configuration-autodiscover.html#_kubernetes

3

@Michal_Pristas
Seems that var/log/container/.. is accessible to filebeat since I am receiving logs from the containers. I am also writing my own logs from my express server to that location but filebeat is not able to read these files.
The way I solved this is that I am logging directly to the console from my express server and filebeat is able to get those, but I am not sure why the log file is not being picked up.

I'll look into auto discover, thanks!