How to mount multiple configmap as multiple volumes to same directory

General Discussions
1

Hi all,
I’m kubernetes newbie, I started to learn about K8S, I’m trying AKS trial I try to deploy a webdevops/php-nginx container, but I get problem, this is my deployment manifest :

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-frontend-deploy
  labels:
    app: php-nginx
spec:
  selector:
    matchLabels:
      app: php-nginx
      tier: frontend
  replicas: 1
  template:
    metadata:
      labels:
        app: php-nginx
        tier: frontend
    spec:
      containers:
      - name: php-nginx
        image: webdevops/php-nginx:8.0-alpine
        volumeMounts:
        - name: nginx-config
          mountPath: /opt/docker/etc/nginx/conf.d/web-frontend.conf
          subPath: web-frontend.conf
        - name: phpfpm-config
          mountPath: /opt/docker/etc/php/fpm/pool.d/application.conf
          subPath: application.conf
        - name: phpini-config
          mountPath: /opt/docker/etc/php/php.ini
          subPath: php.ini
        resources:
          requests:
            cpu: 200m
            memory: 400Mi
        ports:
        - containerPort: 80
      volumes:
        - name: nginx-config
          configMap:
            name: nginx-config
        - name: phpfpm-config
          configMap:
            name: phpfpm-config
        - name: phpini-config
          configMap:
            name: phpini-config

As webdevops/php-nginx document, I want to customize nginx, php-fpm, phi.ini by:

  • mount nginx-config to /opt/docker/etc/nginx/conf.d/web-frontend.conf
  • mount phpfpm-config to /opt/docker/etc/php/fpm/pool.d/application.conf
  • mount phpini-config to /opt/docker/etc/php/php.ini
    in my container, I have created these configmaps already, I run manifest but deployment and pod cannot be created

kubectl get deployments
NAME READY UP-TO-DATE AVAILABLE AGE
web-frontend-deploy 0/1 1 0 6m45s

kubectl get pods
NAME READY STATUS RESTARTS AGE
web-frontend-deploy-6c994cb79b-t9pd2 0/1 CrashLoopBackOff 6 6m51s

kubectl describe pod/web-frontend-deploy-6c994cb79b-t9pd2
…

State:          Waiting
  Reason:       CrashLoopBackOff
Last State:     Terminated
  Reason:       Error
  Exit Code:    1
  Started:      Wed, 07 Jul 2021 14:29:00 +0700
  Finished:     Wed, 07 Jul 2021 14:29:00 +0700
Ready:          False
Restart Count:  6
Requests:
  cpu:        200m
  memory:     400Mi
Environment:  <none>
Mounts:
  /opt/docker/etc/nginx/conf.d/web-frontend.conf from nginx-config (rw,path="web-frontend.conf")
  /opt/docker/etc/php/fpm/pool.d/application.conf from phpfpm-config (rw,path="application.conf")
  /opt/docker/etc/php/php.ini from phpini-config (rw,path="php.ini")
  /var/run/secrets/kubernetes.io/serviceaccount from default-token-xdrlr (ro)

Events:
Type Reason Age From Message

Normal Scheduled 7m19s default-scheduler Successfully assigned …/web-frontend-deploy-6c994cb79b-t9pd2 to aks-agentpool-19144222-vmss000000
Normal Pulled 5m45s (x5 over 7m19s) kubelet Container image “…” already present on machine
Normal Created 5m45s (x5 over 7m19s) kubelet Created container php-nginx
Normal Started 5m45s (x5 over 7m19s) kubelet Started container php-nginx
Warning BackOff 2m13s (x25 over 7m17s) kubelet Back-off restarting failed container

If I just leave 1 of them (nginx, phpfpm, phpini) in manifest file, it works fine.
How can I fix it ? I look forward to hearing from your experience , thank you very much.
My version

kubectl version --short
Client Version: v1.21.2
Server Version: v1.19.11
WARNING: version difference between client (1.21) and server (1.19) exceeds the supported minor version skew of +/-1
2

I tried to debug pod:

C:\Users\jack.chuong>kubectl logs web-frontend-deploy-6cb98c986c-md2jh
→ Executing /opt/docker/provision/entrypoint.d/05-permissions.sh
→ Executing /opt/docker/provision/entrypoint.d/20-nginx.sh
→ Executing /opt/docker/provision/entrypoint.d/20-php-fpm.sh
/opt/docker/provision/entrypoint.d/20-php-fpm.sh: line 7: /opt/docker/etc/php/fpm/pool.d/application.conf: Read-only file system
So php-fpm conf is read-only and I cannot override it, if I comment out php-fpm part , it works find. Is there a way to get over it?

3

I bypass it by using env

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-frontend-deploy
  labels:
    app: php-nginx
spec:
  selector:
    matchLabels:
      app: php-nginx
      tier: frontend
  replicas: 1
  template:
    metadata:
      labels:
        app: php-nginx
        tier: frontend
    spec:
      containers:
      - name: php-nginx
        image: webdevops/php-nginx:8.0-alpine
        env:
        - name: FPM_PM_MAX_CHILDREN
          value: "100"
        volumeMounts:
        - name: nginx-config
          mountPath: /opt/docker/etc/nginx/conf.d/web-frontend.conf
          subPath: web-frontend.conf
 #       - name: phpfpm-config
 #         mountPath: /opt/docker/etc/php/fpm/pool.d/application.conf
 #         subPath: application.conf
        - name: phpini-config
          mountPath: /opt/docker/etc/php/php.ini
          subPath: php.ini
        resources:
          requests:
            cpu: 200m
            memory: 400Mi
        ports:
        - containerPort: 80
      volumes:
        - name: nginx-config
          configMap:
            name: nginx-config
#        - name: phpfpm-config
#          configMap:
#            name: phpfpm-config
        - name: phpini-config
          configMap:
            name: phpini-config

But I expect another way.