Improve routing between containers

Create user network nginx-internal
and use Docker's internal DNS server
to resolve containers by hostname.

roles/jellyfin/tasks/main.yml

@@ -11,6 +11,8 @@
   docker_container:
     name: 'jellyfin'
     image: linuxserver/jellyfin
+    networks:
+      - name: nginx-internal
     volumes:
       - "{{ data_folder }}/jellyfin:/config"
       - "{{ media.tv }}:/data/tv"

roles/jellyfin/templates/jellyfin.conf.j2

@@ -1,15 +1,12 @@
 server {
     listen 80;
-    server_name "jellyfin.{{ base_domain }}";
-    set $jellyfin {{ server_ip }};
-    #resolver 127.0.0.1 valid=30;
     return 301 https://$host$request_uri;
 }
 
 server {
     listen 443 ssl http2;
     server_name "jellyfin.{{ base_domain }}";
-    set $jellyfin {{ server_ip }};
+    set $jellyfin jellyfin;
 
     # Security/XSS Mitigation Headers
     add_header X-Frame-Options "SAMEORIGIN";

roles/nginx/tasks/main.yml

@@ -58,10 +58,18 @@
     src: nginx.conf.j2
     dest: "{{ data_folder }}/nginx/nginx.conf"
     mode: '0755'
+- name: create nginx bridge network
+  docker_network:
+    name: nginx-internal
+    attachable: true
+    internal: true
+    state: present
 - name: run container
   docker_container:
     name: 'nginx'
     image: nginx
+    networks:
+      - name: nginx-internal
     volumes:
       - "{{ data_folder }}/nginx/nginx.conf:/etc/nginx/nginx.conf"
       - "{{ data_folder }}/nginx/{{ base_domain }}.key:/etc/nginx/{{ base_domain }}.key"

roles/nginx/templates/nginx.conf.j2

@@ -26,6 +26,7 @@ http {
     keepalive_timeout  65;
 
     #gzip  on;
+    resolver 127.0.0.11 valid=30;
     ssl_certificate /etc/nginx/{{ base_domain }}.crt;
     ssl_certificate_key /etc/nginx/{{ base_domain }}.key;
     include /etc/nginx/conf.d/*.conf;