Pgpool 无法在 kubernetes 作为 pod 启动

Question

I have hosted pgpool on a container and given the container config for kubernetes deployment -

Mountpaths -

- name: cgroup
    mountPath: /sys/fs/cgroup:ro
- name: var-run
    mountPath: /run

And Volumes for mountpath for the cgroups are mentioned as below -

- name: cgroup
    hostPath:
      path: /sys/fs/cgroup
      type: Directory
- name: var-run
  emptyDir:
      medium: Memory

Also in kubernetes deployment I have passed -

 securityContext:
    privileged: true

But when I open the pod and exec inside it to check the pgpool status I get the below issue -

[root@app-pg-6448dfb58d-vzk67 /]# journalctl -xeu pgpool
-- Logs begin at Sat 2020-07-04 16:28:41 UTC, end at Sat 2020-07-04 16:29:13 UTC. --
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 systemd[1]: Started Pgpool-II.
-- Subject: Unit pgpool.service has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit pgpool.service has finished starting up.
-- 
-- The start-up result is done.
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: [1-1] 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "stateme
nt_level_load_balance"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "statement_lev
el_load_balance"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "auto_failback
"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "auto_failback
_interval"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "enable_consen
sus_with_half_votes"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "enable_shared
_relcache"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "relcache_quer
y_target"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: FATAL:  could not open pid file as /var/run/pgpool-II-11/p
gpool.pid. reason: No such file or directory
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 systemd[1]: pgpool.service: main process exited, code=exited, status=3/NOTIMPLEMENTED
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 systemd[1]: Unit pgpool.service entered failed state.
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 systemd[1]: pgpool.service failed.

Systemctl status pgpool inside the pod container -

➜  app-app kubectl exec -it app-pg-6448dfb58d-vzk67  -- bash
[root@app-pg-6448dfb58d-vzk67 /]# systemctl status pgpool
● pgpool.service - Pgpool-II
   Loaded: loaded (/usr/lib/systemd/system/pgpool.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Sat 2020-07-04 16:28:41 UTC; 1h 39min ago
  Process: 34 ExecStart=/usr/bin/pgpool -f /etc/pgpool-II/pgpool.conf $OPTS (code=exited, status=3)
 Main PID: 34 (code=exited, status=3)

Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "stat...lance"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "auto...lback"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "auto...erval"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "enab...votes"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "enab...cache"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: INFO:  unrecognized configuration parameter "relc...arget"
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 pgpool[34]: 2020-07-04 16:28:41: pid 34: FATAL:  could not open pid file as /var/run/pgpoo...ectory
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 systemd[1]: pgpool.service: main process exited, code=exited, status=3/NOTIMPLEMENTED
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 systemd[1]: Unit pgpool.service entered failed state.
Jul 04 16:28:41 app-pg-6448dfb58d-vzk67 systemd[1]: pgpool.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

If required this is the whole deployment sample -

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app-pg
  labels:
    helm.sh/chart: app-pgpool-1.0.0
    app.kubernetes.io/name: app-pgpool
    app.kubernetes.io/instance: app-service
    app.kubernetes.io/version: "1.0.3"
    app.kubernetes.io/managed-by: Helm
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: app-pgpool
      app.kubernetes.io/instance: app-service
  template:
    metadata:
      labels:
        app.kubernetes.io/name: app-pgpool
        app.kubernetes.io/instance: app-service
    spec:
      volumes:
        - name: "pgpool-config"
          persistentVolumeClaim:
            claimName: "pgpool-pvc"
        - name: cgroup
          hostPath:
            path: /sys/fs/cgroup
            type: Directory
        - name: var-run
          emptyDir:
            # Tmpfs needed for systemd.
            medium: Memory
      # volumes:
      #   - name: pgpool-config
      #     configMap:
      #       name: pgpool-config
      # - name: pgpool-config
      #   azureFile:
      #     secretName: azure-fileshare-secret
      #     shareName: pgpool
      #     readOnly: false
      imagePullSecrets:
        - name: app-secret
      serviceAccountName: app-pg
      securityContext:
        {}
      containers:
        - name: app-pgpool
          securityContext:
            {}
          image: "appacr.azurecr.io/pgpool:1.0.3"
          imagePullPolicy: IfNotPresent
          securityContext:
            privileged: true
          stdin: true
          tty: true
          ports:
            - name: http
              containerPort: 9999
              protocol: TCP
          # livenessProbe:
          #   httpGet:
          #     path: /
          #     port: http
          # readinessProbe:
          #   httpGet:
          #     path: /
          #     port: http
          resources:
            {}
          volumeMounts:
            - name: "pgpool-config"
              mountPath: /etc/pgpool-II
            - name: cgroup
              mountPath: /sys/fs/cgroup:ro
            - name: var-run
              mountPath: /run

UPDATE -

Running this same setup on dockerfile runs perfectly good no issues at all -

version: '2'
services:

  pgpool:
    container_name: pgpool
    image: appacr.azurecr.io/pgpool:1.0.3
    logging:
      options:
        max-size: 100m
    ports:
      - "9999:9999"
    networks:
      vpcbr:
        ipv4_address: 10.5.0.2
    restart: unless-stopped
    volumes:
     - /sys/fs/cgroup:/sys/fs/cgroup:ro
     - $HOME/Documents/app/docker-compose/pgpool.conf:/etc/pgpool-II/pgpool.conf
     - $HOME/Documents/app/docker-compose/pool_passwd:/etc/pgpool-II/pool_passwd
    privileged: true
    stdin_open: true
    tty: true

I dont know what am I doing wrong I am not able to start this pgpool anyway and not able to pinpoint the issue. What permission are we missing here or whether cgroups is the culprit? or not?

Some direction would be appreciated.

Answer 1

while this might not be a direct answer to your question, I have seen some very cryptic errors when trying to run any postgresql product from raw manifest, my recommandations would be to try leveraging the chart from Bitnami, they have put a lot of effort in ensuring that all of the security / permission culpits are taken care of properly.

https://github.com/bitnami/charts/tree/master/bitnami/postgresql-ha

Hopefully, this help.

Also, if you do not want to use Helm, you can run the help template command

https://helm.sh/docs/helm/helm_template/

this will generate manifest out of the chart's template file based on the provided values.yaml