Watchtower: Reload nginx proxy config on image update

[norpan]

Hi,
I'm trying to use watchtower to update my applications when I push a new image. My problem is that they are behind an nginx reverse proxy, and when the containers restart they sometimes get a new IP address. They are referred to by name in the nginx config, but it doesn't do a new lookup on each request, so I have to send it a SIGHUP.

I'm wondering if there is a way to configure watchtower send SIGHUP to my nginx container whenever it updates an image.

[qqilihq]

We're just having very similar issues, and I think if the link would work as expected (see #126), this problem would also be resolved.

[norpan]

I think I solved it by specifying in nginx.conf server section resolver and valid=1s

[qqilihq]

Interesting, that hadn't even come to my mind. Although I solved it differently for now, this is very valuable input. Thanks!

[redge76]

Some cool project https://traefik.io/
Great reverse proxy tailored for Docker.

[yspreen]

@norpan I'm facing the same issue. Could you maybe elaborate on:
specifying in nginx.conf server section resolver and valid=1s
?

[norpan]

So, it's finally solved.
The two things that you need to do is to specify a resolver (which is 127.0.0.11 in docker) in your server config, and use variables in the proxy_pass to make the resolver actually resolve each time. When using variables in proxy_pass you need to create the whole new access url.

So, here is what my server section looks like:

http {
  server {
    resolver 127.0.0.11 valid=1s;
    set $my_service my_service_name;
    # Admin client
    location / {
      proxy_pass http://$my_service$request_uri;
    }

[simskij]

So, it's finally solved.
The two things that you need to do is to specify a resolver (which is 127.0.0.11 in docker) in your server config, and use variables in the proxy_pass to make the resolver actually resolve each time. When using variables in proxy_pass you need to create the whole new access url.

So, here is what my server section looks like:

http {
  server {
    resolver 127.0.0.11 valid=1s;
    set $my_service my_service_name;
    # Admin client
    location / {
      proxy_pass http://$my_service$request_uri;
    }

Thanks for the solution, @norpan ! Would you mind creating a PR updating the readme with your solution? 🙏