[FLINK-24212] kerberos krb5.conf file is mounted as empty directory, not the expected file

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.14.0, 1.15.0
• Fix Version/s: 1.14.0, 1.15.0
• Component/s: Deployment / Kubernetes
• Labels: pull-request-available
• Assignee: LiuZeshan
• Reporter: LiuZeshan
• Created: 08/Sep/21 11:10
• Updated: 30/Nov/21 20:37
• Resolved: 14/Sep/21 01:59

Description

From FLINK-18971，we can mount kerberos krb5 conf file to pod with path /etc/krb5.conf，however if the krb5 conf file is not named krb5.conf (e.g named mykrb5.conf)，the mount path /etc/krb5.conf in pod will be an empty directory, not a file that we expect.

root@mykrb5-conf-test-6dd5c76f87-vfwh5:/# ls /etc/krb5.conf/ -la
total 8
drwxrwxrwx 2 root root 4096 Sep  8 10:42 .
drwxr-xr-x 1 root root 4096 Sep  8 10:42 ..

 

 The reason is that, the code  in KerberosMountDecrator#decroateFlinkPod, we create the deployment like this: 

...
        volumeMounts:
        - mountPath: /etc/krb5.conf
          name: my-krb5conf-volume
          subPath: krb5.conf    
...
      volumes:
      - configMap:
          defaultMode: 420
          items:
          - key: mykrb5.conf
            path: mykrb5.conf
          name: my-krb5conf
        name: my-krb5conf-volume

path value should be set to const value "krb5.conf", not the file name that user provide (path: mykrb5.conf).

 we can use the yaml description file attachment to reproduce the problem.  mykrb5conf.yaml

 

Issue Links

• links to: GitHub Pull Request #17198