unauthorized: authentication required

edit

Firstly enable IITB VPN on your computer. Then run the command.
$sudo docker login docker.cse.iitb.ac.in
If first prompted for password, enter your PC password. Then it asks for username and password. Use the following.
Username: cse_user

Password: user_auth_pass

These are literally what you need to enter and not your original CSE credentials. The login should be successful post this.
If not, I suggest reinstalling docker correctly.
Hope this resolves the issue.

There might be many reasons that might cause this issue. I will list out a few here.

1. Make sure you are connected to the VPN.

2. Please make sure you are logging in with the correct credentials, which are as follows:-
   Username: cse_user
   Password: user_auth_pass
   No CSE LDAP here.

3. This also might happen due to request timeout, because of the load on either VPN or Docker Registry. In that case, just reconnecting to VPN or retrying the logging in will do.

But even if the above methods do not work for you. You can go ahead and file a bug. But before you file a bug make sure you send us the debug log of the docker daemon.

In order to send the debug log, the docker daemon has to be run in debug mode.

Do not worry this is just a one time process.

The following procedure will set the docker in debug mode in Ubuntu:-

1. Open the file /etc/docker/daemon.json in the text editor of your choice (will require a sudo). If you do not have one you can create the file in using the command sudo touch /etc/docker/daemon.json.

2. Add the line "debug": true in the json. The resulting json should look like
   

   { "debug": true }

3. Restart the docker daemon, by running sudo systemctl restart docker.

The above steps will make the docker daemon run in debug mode. Again, this is a one time process.

Now, whenever you can request to the Docker registry for login and if the request still fails, Open up the terminal and run the command journalctl -u docker| tail -n 10. Some text will output to the terminal which is the Debug log. Now copy that log and paste it into the bug request.

This will give us more insight into the error.

Thanks.

PS: You do not have to login every time you boot, just once, Docker will autologin for you unless you manually run the docker logout docker.cse.iitb.ac.in