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  • Do a describe of the pod using command kubectl describe pod <pod-name>, to ensure theĀ Init Container section is presented as your defined in your yaml template.
  • If it does not exist, it is possible that your Kubernetes version supports a different format for the init-containers:

    init-containers syntax supported by Kubernetes 1.5, 1.6 and 1.7 and not supported by Kubernetes 1.8 and greaterinitContainers syntax supported from Kubernetes 1.6 and greater

    Init container is defined under

    spec.template.metadata.annotations."pod.beta.kubernetes.io/init-containers

    Code Block
    languagexml
    titleAn example of init container by beta annotation
    linenumberstrue
    collapsetrue
    apiVersion: apps/v1beta1
    kind: StatefulSet
    metadata:
      name: sdnc
      ...
    spec:
      ...
      template:
        metadata:
          ...
          annotations:
            pod.beta.kubernetes.io/init-containers: '[
              {
                  "args": [
                      "--container-name",
                      "sdnc-db-container"
                  ],
                  "command": [
                      "/root/ready.py"
                  ],
                  "env": [
                      {
                          "name": "NAMESPACE",
                          "valueFrom": {
                              "fieldRef": {
                                  "apiVersion": "v1",
                                  "fieldPath": "metadata.namespace"
                              }
                          }
                      }
                  ],
                  "image": "{{ .Values.image.readiness }}",
                  "imagePullPolicy": "{{ .Values.pullPolicy }}",
                  "name": "sdnc-readiness"
              }
              ]'
        spec:
          containers:
          ...

    Init container is defined under spec.template.spec.initContainers

    Code Block
    languagexml
    titleAn example of init container by spec.initContainers
    linenumberstrue
    collapsetrue
    apiVersion: apps/v1beta1
    kind: StatefulSet
    metadata:
      name: sdnc
      ...
    spec:
      ...
      template:
        ...
        spec:
          initContainers:
          - command:
            - /root/ready.py
            - "--container-name"
            - "sdnc-db-container"
            env:
            - name: NAMESPACE
              valueFrom:
                fieldRef:
                  apiVersion: v1
                  fieldPath: metadata.namespace
            image: "{{ .Values.image.readiness }}"
            imagePullPolicy: {{ .Values.pullPolicy }}
            name: sdnc-readiness
          containers:
          ...

...

Expand
titleExample of restarting dead instance by deleting pod
Expand
titlesdnc-0 pod runs fine at the beginning

Image RemovedImage Added

Expand
titlemanually delete the sdnc-0 pod

Image RemovedImage Added

Expand
titleonce the sdnc-0 pod is fully terminated, a new sdnc-0 pod will be initialized

Image RemovedImage Added

Expand
titleThe new sdnc-0 pod will be brought to running status to replace the initial sdnc-0

Image RemovedImage Added

Expand
titleThe new and initial sdnc-0 pod has the same name (although with different internal IP)
Description of Initial sdnc-0Description of restarted sdnc-0

ubuntu@sdnc-k8s:~/oom/kubernetes/config$ kubectl describe pod sdnc-0 -n onap-sdnc
Name: sdnc-0
Namespace: onap-sdnc
Node: sdnc-k8s-2/10.147.90.6
Start Time: Thu, 23 Nov 2017 22:37:00 +0000
Labels: app=sdnc
controller-revision-hash=sdnc-2443484326
Annotations: kubernetes.io/created-by={"kind":"SerializedReference","apiVersion":"v1","reference":{"kind":"StatefulSet","namespace":"onap-sdnc","name":"sdnc","uid":"a576a1a3-d09f-11e7-957f-0269cb13eff1","apiVersio...
pod.alpha.kubernetes.io/init-container-statuses=[{"name":"sdnc-readiness","state":{"terminated":{"exitCode":0,"reason":"Completed","startedAt":"2017-11-23T22:37:08Z","finishedAt":"2017-11-23T22:37:53Z...
pod.alpha.kubernetes.io/init-containers=[{"name":"sdnc-readiness","image":"oomk8s/readiness-check:1.0.0","command":["/root/ready.py"],"args":["--container-name","sdnc-db-container"],"env":[{"name":"NA...
pod.beta.kubernetes.io/init-container-statuses=[{"name":"sdnc-readiness","state":{"terminated":{"exitCode":0,"reason":"Completed","startedAt":"2017-11-23T22:37:08Z","finishedAt":"2017-11-23T22:37:53Z"...
pod.beta.kubernetes.io/init-containers=[{"name":"sdnc-readiness","image":"oomk8s/readiness-check:1.0.0","command":["/root/ready.py"],"args":["--container-name","sdnc-db-container"],"env":[{"name":"NAM...
Status: Running
IP: 10.42.107.61
Created By: StatefulSet/sdnc
Controlled By: StatefulSet/sdnc

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ubuntu@sdnc-k8s:~/oom/kubernetes/oneclick$ kubectl describe pod sdnc-0 -n onap-sdnc
Name: sdnc-0
Namespace: onap-sdnc
Node: sdnc-k8s-2/10.147.90.6
Start Time: Thu, 23 Nov 2017 22:54:10 +0000
Labels: app=sdnc
controller-revision-hash=sdnc-2443484326
Annotations: kubernetes.io/created-by={"kind":"SerializedReference","apiVersion":"v1","reference":{"kind":"StatefulSet","namespace":"onap-sdnc","name":"sdnc","uid":"a576a1a3-d09f-11e7-957f-0269cb13eff1","apiVersio...
pod.alpha.kubernetes.io/init-container-statuses=[{"name":"sdnc-readiness","state":{"terminated":{"exitCode":0,"reason":"Completed","startedAt":"2017-11-23T22:54:15Z","finishedAt":"2017-11-23T22:54:15Z...
pod.alpha.kubernetes.io/init-containers=[{"name":"sdnc-readiness","image":"oomk8s/readiness-check:1.0.0","command":["/root/ready.py"],"args":["--container-name","sdnc-db-container"],"env":[{"name":"NA...
pod.beta.kubernetes.io/init-container-statuses=[{"name":"sdnc-readiness","state":{"terminated":{"exitCode":0,"reason":"Completed","startedAt":"2017-11-23T22:54:15Z","finishedAt":"2017-11-23T22:54:15Z"...
pod.beta.kubernetes.io/init-containers=[{"name":"sdnc-readiness","image":"oomk8s/readiness-check:1.0.0","command":["/root/ready.py"],"args":["--container-name","sdnc-db-container"],"env":[{"name":"NAM...
Status: Running
IP: 10.42.185.227
Created By: StatefulSet/sdnc
Controlled By: StatefulSet/sdnc

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