How can I upgrade phabricator peaceful

Hi, we run phabricator by docker Image(https://hub.docker.com/r/redpointgames/phabricator) ,
Dockerfile: https://github.com/RedpointGames/phabricator. this image use Suse42 and
OpenSSH_7.2p2.

but few days age, ssh command is not effective any more , every operator is timeout , the behavior like this question: Newly added SSH keys not working

we want to upgrade OpenSSH version and pharbicator to the last stable version . we want to comfirm the upgrade is smooth。 please help!

Looks like this docker image is abandoned, so you might run into issues regarding the image itself.
Upgrading Phabricator is usually easy, but since you’re probably 2 years out of date, you should be ready for some problems.

You should go over the change logs for the period to see what might break.