add user kubernetes when no root

readme.md

This explain how to add Linux user when running pod as no-root.

This fix use an initContainer to append a line to /etc/passwd , then mount it as a file within container to run.

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata: {}
spec:
  template:
    metadata: {}
    spec:
      volumes:
        - name: etc-hack
          emptyDir: {}
      initContainers:
      - name: fix-user
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
        imagePullPolicy: {{ .Values.image.pullPolicy }}
        command:
        - '/bin/sh'
        - '-c'
        - >
          myuid=$(id -u)
          mygid=$(id -g)
          uidentry=$(getent passwd $myuid)

          cp /etc/passwd /opt/my-etc/passwd
          
          if [ -z "$uidentry" ] ; then
              if [ -w /opt/my-etc/passwd ] ; then
                  echo "$myuid:x:$myuid:$mygid:zeppelin uid:${PWD}:/bin/false" >> /opt/my-etc/passwd
              else
                  echo "Container ENTRYPOINT failed to add passwd entry for zeppelin UID"
              fi
          fi
        resources:
          requests:
            cpu: 10m
            memory: 16Mi
          limits:
            cpu: 50m
            memory: 32Mi
        volumeMounts:
        - name: etc-hack
          mountPath: /opt/my-etc
      containers:
        - name: {{ .Chart.Name }}
          image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
          imagePullPolicy: {{ .Values.image.pullPolicy }}
          volumeMounts:
          - name: etc-hack
            mountPath: /etc/passwd
            subPath: passwd