Auth failed: invalid password or missing SSH Key while import project in eclipse docker container
First, make sure the Eclipse running inside the container do so as root.
Because an SSH URL will look for its key in ~/.ssh, and the container has its /root/.ssh filled with your shared files, not ~<auser>/.ssh.
Second, check if your SSH key is passphrase-protected (which means you would need, on your host, where SSH is working, an ssh-agent to cache the passphrase)