Mongodump error creating directory for metadata file : Access denied

Working with Data Developer Tools
,
1

I have created a database and accompanying user for the database but It appears I cant do backups with that user and neither can I add the backup role to the user. Having checked documentation I added a user but this time at the admin database level ( use admin ) and added backup role for the same.

However when I attempt to do a backup I am getting an error Failed: error dumping metadata: error creating directory for metadata file /var/backups/…: mkdir /var/backups/…: permission denied

Steps
1.

kubectl -n <namespace> exec -it <pod_name> -- sh

(mongo is running in kubernetes)

use admin

(switch to admin user)

db.createUser( {user: "backupuser", pwd: "abc123", roles: ["root", "userAdminAnyDatabase", "dbAdminAnyDatabase", "readWriteAnyDatabase","backup"], mechanisms:["SCRAM-SHA-256"]})

 `db.getUsers({ filter: { mechanisms: "SCRAM-SHA-256" } })`

(Verify if user exists)

mongodump -u backupuser -p abc123 --authenticationDatabase admin -d TESTDB --out /var/backups/dump-25-05-22 --gzip

Is it possible to even amend permissions for this user in such a case or I should be looking somewhere else. In the container it seems I cant do any permission updates (for the group) but the user already has all permissions on /var/backups :

ls -la
total 8
drwxr-xr-x 2 root root 4096 Feb 18  2021 .
drwxr-xr-x 1 root root 4096 Feb 18  2021 ..

I am not convinced either that I should be going even this far. The backup should execute out of the box as per the user I added.

What exactly am I missing ?

2

Only OS user root has write permission. The OS user that runs the command mongodump … needs to have write access to /var/backups/.

3

hello @steevej I am not quite sure how to grant those permissions and from which context. Do I grant for users in the container host or the kubernetes host machine?
By OS user you mean a user profile on the kubernetes host?

4

I do not use k18s in conjunction with MongoDB, so I cannot answer more than:

The user executing the command mongodump needs to have write access to the directory written to.