Fix PHP-FPM not reachable from nginx container (502 errors) (#266)

* Initial plan

* fix: fix issues in nginx:app communication

* Update nginx config comment to match implementation

Co-authored-by: Neunerlei <22350956+Neunerlei@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: neunerlei <ich@neunerlei.eu>
Co-authored-by: Neunerlei <22350956+Neunerlei@users.noreply.github.com>

Author: Copilot

_docker_production/nginx.default.conf

@@ -45,14 +45,14 @@ http {
     }
 
     server {
-        listen 443 ssl http2;
-        listen [::]:443 ssl http2;
+        listen 443 ssl;
+        listen [::]:443 ssl;
+        http2 on;
 
         server_name _;
 
         # Use the internal DNS resolver of Docker
-        # First use the Docker embedded DNS server, then Google DNS and Cloudflare DNS as fallback
-        resolver 127.0.0.11 8.8.8.8 1.1.1.1 valid=30s;
+        resolver 127.0.0.11 valid=30s;
         resolver_timeout 5s;
 
         root /var/www/html/public;
@@ -171,7 +171,8 @@ http {
 		}
 
 		location ~ \.php$ {
-            fastcgi_pass   app:9000;
+            set $upstream_app app:9000;
+            fastcgi_pass $upstream_app;
             fastcgi_index  index.php;
             fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
             include        fastcgi_params;
@@ -185,7 +186,8 @@ http {
         ### Error Handling
         error_page 404 = @notfound;
         location @notfound {
-            fastcgi_pass app:9000;
+            set $upstream_app app:9000;
+            fastcgi_pass $upstream_app;
             fastcgi_param SCRIPT_FILENAME /var/www/html/public/index.php;
             fastcgi_param REQUEST_URI /404;
             include fastcgi_params;

docker/php/config/fpm-pool.conf

@@ -13,7 +13,7 @@ error_log = /dev/stderr
 ;                            (IPv6 and IPv4-mapped) on a specific port;
 ;   '/path/to/unix/socket' - to listen on a unix socket.
 ; Note: This value is mandatory.
-listen = 127.0.0.1:9000
+listen = 9000
 user = www-data
 group = www-data
 
@@ -74,4 +74,4 @@ ping.path = /fpm-ping
 
 ; The access log file
 ; Default: not set
-access.log = /dev/null
+access.log = /dev/null