sh Job container after it is stopped

Question

I am backuping my Postgresql database using this cronjob:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: postgres-backup
spec:
  schedule: "0 2 * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: postgres-backup
            image: postgres:10.4
            command: ["/bin/sh"]
            args: ["-c", 'echo "$PGPASS" > /root/.pgpass && chmod 600 /root/.pgpass && pg_dump -Fc -h <host> -U <user> <db> > /var/backups/backup.dump']
            env:
            - name: PGPASS
              valueFrom:
                secretKeyRef:
                  name: pgpass
                  key: pgpass
            volumeMounts:
            - mountPath: /var/backups
              name: postgres-backup-storage
          restartPolicy: Never
          volumes:
          - name: postgres-backup-storage
            hostPath:
              path: /var/volumes/postgres-backups
              type: DirectoryOrCreate

The cronjob gets successfully executed, the backup is made and saved in the container of the Job but this container is stopped after successful execution of the script. of course I want to access the backup files in the container but I can't because it is stopped/terminated.

is there a way to execute shell commands in a container after it is terminated, so I can access the backup files saved in the container?

I know that I could do that on the node, but I don't have the permission to access it.

Answer 1

@confused genius gave me a great idea to create another same container to access the dump files so this is the solution that works:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: postgres-backup
spec:
  schedule: "0 2 * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: postgres-backup
            image: postgres:10.4
            command: ["/bin/sh"]
            args: ["-c", 'echo "$PGPASS" > /root/.pgpass && chmod 600 /root/.pgpass && pg_dump -Fc -h <host> -U <user> <db> > /var/backups/backup.dump']
            env:
            - name: PGPASS
              valueFrom:
                secretKeyRef:
                  name: dev-pgpass
                  key: pgpass
            volumeMounts:
            - mountPath: /var/backups
              name: postgres-backup-storage
          - name: postgres-restore
            image: postgres:10.4
            volumeMounts:
            - mountPath: /var/backups
              name: postgres-backup-storage
          restartPolicy: Never
          volumes:
          - name: postgres-backup-storage
            hostPath:
            # Ensure the file directory is created.
              path: /var/volumes/postgres-backups
              type: DirectoryOrCreate

after that one just needs to sh into the "postgres-restore" container and access the dump files.

thanks