GitLab can't reach PlantUml in docker container

I believe the issue is that you are running the plantuml in a docker container and then trying to reach it via gitlab (on localhost) with name.

In order to check if that is the issue please change

proxy_pass  http://plantuml:8080/

to

proxy_pass http://localhost:8080/

and trying again with the first approach.

Your second approach seems to be missing the container port in the url.

You are right.
PlantUML TomCat or Jetty has the same issue, only serving HTTP not HTTPS.
If you need to have HTTPS then it’s up to nginx to provide that layer.

Here is my Nginx config for my local plantuml. I know you want the whole integration with gitlab. Maybe because this is 6 month old, you found a solution.

Anyway you can see that nginx is taking care of the ssl while the proxy_pass is only over http.

upstream jetty {  server 127.0.0.1:8084 weight=100 max_fails=5 fail_timeout=5;}
server {
    listen 443 ssl; # managed by Certbot
    listen [::]:443 ssl; # managed by Certbot

    listen 80;
    listen [::]:80;
     
    server_name plantuml.mycompany.example;
    
    access_log /var/log/nginx/plantuml.mycompany.example.access.log;
    error_log /var/log/nginx/plantuml.mycompany.example.error.log;
    
    # RSA certificate
    ssl_certificate /etc/letsencrypt/live/mycompany.example-0001/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/mycompany.example-0001/privkey.pem; # managed by Certbot

    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
     
    # Redirect non-https traffic to https
    if ($scheme != "https") {
        return 301 https://$host$request_uri;
    } # managed by Certbot

    location / {
     proxy_set_header X-Forwarded-Host $host;
     proxy_set_header X-Forwarded-Server $host;
     proxy_pass http://jetty/;
     sub_filter '"http://jetty/'  '"/';
     sub_filter_once off;
    }
}

If you found a solution, please share.

GitLab can't reach PlantUml in docker container

Answers