I am running an Ubuntu self-hosted build agent for Azure DevOps in Container Instances and container outputs only: Determining matching Azure Pipelines agent. and that's it.
It has PAT with full access to whole organization, given agent pool really exists and the URL is correct as well. THe only thing that comes to my mind is that I see our URL as https://XXXX.visualstudio.com/ but I gave the agent url like https://dev.azure.com/XXX which still seems to be working when used in the browser.
How to solve this, please?
The problem was that Agent was put into the subnet which had not NSG, therefore it denied all in/outbound traffic. So we added a NSG to this subnet with outbound rule for port 443 TCP and it works now.