Couldn't deduce an advertise address

[John]

Hello.

On a CentOS 7 machine that I manage myself, I am running Gitlab 12.0.1.

Before a few updates back, everything was buttery smooth but an update broke my installation that whenever I go to my front page, I get the `Deploy in progress` message.

I did some debugging. `gitlab-ctl status` states that everything is up and running except for `alertmanager`.

I did a restart by `gitlab-ctl restart` which states that everything has restarted but afterwards checking the status again, `alertmanager` can be seen as down again.

I did a:

- `gitlab-ctl stop`
- `gitlab-ctl reconfigure`
- `gitlab-ctl start`

in that order and everything went fine; however, `alertmanager` goes down again immediately.

And `gitlab-ctl tail alertmanager` states the following:

    2019-06-27_09:04:19.75237 level=warn ts=2019-06-27T09:04:19.751036139Z caller=cluster.go:154 component=cluster err="couldn't deduce an advertise address: no private IP found, explicit advertise addr not provided"
    2019-06-27_09:04:19.75630 level=error ts=2019-06-27T09:04:19.756225537Z caller=main.go:202 msg="unable to initialize gossip mesh" err="create memberlist: Failed to get final advertise address: No private IP address found, and explicit IP not provided"
    2019-06-27_09:04:20.79887 level=info ts=2019-06-27T09:04:20.798268353Z caller=main.go:177 msg="Starting Alertmanager" version="(version=0.16.2, branch=master, revision=)"
    2019-06-27_09:04:20.79890 level=info ts=2019-06-27T09:04:20.798339248Z caller=main.go:178 build_context="(go=go1.11.10, user=GitLab-Omnibus, date=)"
    2019-06-27_09:04:20.80945 level=warn ts=2019-06-27T09:04:20.806462267Z caller=cluster.go:154 component=cluster err="couldn't deduce an advertise address: no private IP found, explicit advertise addr not provided"
    2019-06-27_09:04:20.81497 level=error ts=2019-06-27T09:04:20.814894348Z caller=main.go:202 msg="unable to initialize gossip mesh" err="create memberlist: Failed to get final advertise address: No private IP address found, and explicit IP not provided"
    2019-06-27_09:04:21.85821 level=info ts=2019-06-27T09:04:21.857774453Z caller=main.go:177 msg="Starting Alertmanager" version="(version=0.16.2, branch=master, revision=)"
    2019-06-27_09:04:21.85823 level=info ts=2019-06-27T09:04:21.857842577Z caller=main.go:178 build_context="(go=go1.11.10, user=GitLab-Omnibus, date=)"
    2019-06-27_09:04:21.86780 level=warn ts=2019-06-27T09:04:21.865566339Z caller=cluster.go:154 component=cluster err="couldn't deduce an advertise address: no private IP found, explicit advertise addr not provided"
    2019-06-27_09:04:21.87528 level=error ts=2019-06-27T09:04:21.8751892Z caller=main.go:202 msg="unable to initialize gossip mesh" err="create memberlist: Failed to get final advertise address: No private IP address found, and explicit IP not provided"

So, obviously, there is something wrong but what it is. I've checked out similar issues but I don't know what I have to do specifically.

Thanks.

p.s. Also, it should be noted that I'm not making use of the Nginx installation that comes packaged with gitlab-ce which is disabled anyway but I'm running my gitlab instance on my Apache installation. I restarted Apache somewhere along the way as well which yielded no errors.