K8s container initialization design

[oxess]

Hi!
This configuration under k8s takes to long time run.
Maybe use a initial container pattern?

Pod config will have a initial container with download tar and unpacking.
This will better for health checking by k8s.

This require small changes in entrypoint and copy logic to init.sh

Example deployment config:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nominatim
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nominatim
  template:
    metadata:
      labels:
        app: nominatim
    spec:
      initContainers:
      - name: nominatim
        image: peterevans/nominatim-k8s:latest
        command: ["init.sh"]
        volumeMounts:
          - name: pg-data
            mountPath: /var/lib/postgresql/9.5/main
      containers:
      - name: nominatim
        image: peterevans/nominatim-k8s:latest
        resources:
          limits:
            memory: "500Mi"
            cpu: "0.2"
          requests:
            memory: "150Mi"
            cpu: "0.06"
        ports:
        - containerPort: 8080
          name: web
        livenessProbe:
          httpGet:
            path: /status.php
            port: web
          failureThreshold: 1
          periodSeconds: 10
        startupProbe:
          httpGet:
            path: /status.php
            port: web
          failureThreshold: 30
          periodSeconds: 10
          initialDelaySeconds: 250
        volumeMounts:
        - name: firebase-credentials-volume
          mountPath: /etc/credentials
          readOnly: true
        - name: pg-data
          mountPath: /var/lib/postgresql/9.5/main
        envFrom:
        - configMapRef:
            name: nominatim-envs-config
      volumes:
      - name: firebase-credentials-volume
        secret:
          secretName: firebase-credentials-secret
      - name: pg-data
        emptyDir: {}