Veritas InfoScale™ 8.0 Support for Containers - Linux

Logging mechanism

InfoScale runs primarily as daemonsets on an OpenShift or a Kubernetes cluster. To access logs of a failed pod/container, the logs must persist beyond the lifecycle of the container. Containerized InfoScale generates logs as log files and container logs. Logs are helpful for debugging purposes. Log files generated by containerized InfoScale persist on the hostPath /var/VRTS/log of each host. You can access Container logs of running InfoScale pods/containers by using oc logs or kubectl logs command.

If DR Controller is configured, controller logs are also included in the Container logs. DR controller logs are independently generated on all peer clusters added in the Global Cluster Membership and hence, logs from all peer OpenShift or Kubernetes clusters must be collected.

To persist container logs beyond the lifecycle of the Container, following methods can be used.

EFK (ElasticSearch, Fluentd, Kibana) - EFK is the default logging stack on OpenShift. See the OpenShift documentation for configuring EFK.

Fluentd log collector - You can use Fluentd log collector to save the container logs at /var/VRTS/log. Fluentd runs as a daemonset on the OpenShift or Kubernetes cluster. Hence, it can collect logs generated at each node. On OpenShift or Kubernetes, Fluentd needs to run with privileged mode to access hostPath volumes. Run the following command to enable this -

oc adm policy add-scc-to-user privileged -z fluentd

Create a file fluentd-infoscale-spec.yaml, and apply the following configuration by using oc command.

apiVersion: v1
kind: ConfigMap
metadata:
  name: infoscale-fluentd-config
  namespace: kube-system
data:
  fluent.conf: |
    <source>
      @type tail
      @id container-input
      read_from_head true
      format none
      path "/var/log/containers/infoscale*.log"
      pos_file "/var/log/infoscale.log.pos"
      tag infoscale.tail.*
    </source>
    <match infoscale.tail.**>
      @type file
      format json
      append true
      path /containerlogs/${tag[5]}
      <buffer tag>
        flush_interval 5s
      </buffer>
      <format>
        @type single_value
        message_key message
      </format>
    </match>

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: fluentd
  namespace: kube-system

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: fluentd
  namespace: kube-system
rules:
- apiGroups:
  - ""
  resources:
  - pods
  - namespaces
  verbs:
  - get
  - list
  - watch

---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: fluentd
roleRef:
  kind: ClusterRole
  name: fluentd
  apiGroup: rbac.authorization.k8s.io
subjects:
- kind: ServiceAccount
  name: fluentd
  namespace: kube-system
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluentd
  namespace: kube-system
  labels:
    k8s-app: fluentd-logging
    kubernetes.io/cluster-service: "true"
spec:
  selector:
    matchLabels:
      name: fluentd
  template:
    metadata:
      labels:
        k8s-app: fluentd-logging
        kubernetes.io/cluster-service: "true"
        name: fluentd
    spec:
      serviceAccount: fluentd
      serviceAccountName: fluentd
      containers:
        - name: fluentd
#
# On Openshift, fluentd needs to run as privileged due to hostPath mounts
#
          securityContext:
            privileged: true

          image: fluent/fluentd-kubernetes-daemonset:v1-debian-elasticsearch
          env:
            - name: FLUENT_UID
              value: "0"
            - name: FLUENT_ELASTICSEARCH_SED_DISABLE
              value: "true"
          volumeMounts:
            - name: config-volume
              mountPath: /fluentd/etc/fluent.conf
              subPath: fluent.conf
            - name: container-logs
              mountPath: /var/log
            - name: hostpath-containerlogs
              mountPath: /containerlogs
#
# for docker containers (usual on vanilla kubernetes), enable below mountpoint
#            - name: varlibdockercontainers
#              mountPath: /var/lib/docker/containers
      volumes:
        - name: config-volume
          configMap:
            name: infoscale-fluentd-config
        - name: container-logs
          hostPath:
            path: /var/log
            type: Directory
        - name: hostpath-containerlogs
          hostPath:
            path: /var/VRTS/log/containers
            type: DirectoryOrCreate
#
# for docker containers (usual on vanilla kubernetes), enable below volume
#        - name: varlibdockercontainers
#          hostPath:
#            path: /var/lib/docker/containers
#            type: Directory

If you have configured DR, add the following to fluentd-infoscale-spec.yaml. You can add it at the end of this file.

<source>
@type tail
@id container-input
read_from_head true
format none
path "/var/log/containers/dr-controller-manager*.log"
pos_file "/var/log/dr-controller.log.pos"
tag infoscale.tail.*
</source>

This configuration enables Fluentd to log all Infoscale containers to the hostPath directory /var/VRTS/log/containers of each host.