Ubuntu Server Issue: Can't Install Packages | Could not get lock /var/lib/dpkg/lock-frontend

I'm using a Ubuntu 22.04 server with Docker containers for smart devices. Lately, I can't install anything because I keep getting a lock-frontend error.

I looked for what's causing the problem but found nothing. I restarted the server, but the problem didn't go away. Whenever I try to install or upgrade something, the same error comes up.

I even tried removing the lock file, but it didn't help. It seems like the system is stuck waiting for itself, and I'm not sure how to fix it.

If I am to kill the first result it simply kills my running dpkg action

The error message:

Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 3003989 (apt)         

sudo dpkg --configure -a does not help either, has the same issues as apt.

Listing running processes for pid results in:

ps aux | grep 3003989
root      3003989  0.1  0.0  13492  7528 pts/1    S+   14:17   0:00 dpkg --configure -a
root      198985  0.0  0.0   6608  2432 pts/4    S+   14:17   0:00 grep --color=auto 3003989

I don't want to reinstall everything. If anyone can help, that would be great. I haven't found anyone else with this problem. Thanks for any help you can give.

The message says /var/lib/dpkg/lock-frontend is held by the process 3003989. So apparently you can KILL the process to fix the issue(most likely)

But before proceeding to kill, check if the PID(In this case, 3003989) is that of any process that might result in damage or data loss of any kind.

Use any of the following commands to find the process:

ps -p <PID>
ps aux | grep <PID>

In your example the PID is 3003989 so ps -p 3003989 or ps aux | grep 3003989

It will list the process, if the process is not related, you may try killing it.

For KILLING the process:

sudo kill <PID>

If that doesn't kill it;

sudo kill -9 <PID>

PROCEED AT YOUR OWN RISK