Nginx reverse proxy combined with Starman server in one image (#46)

* feat: provide image with nginx

* Re-use parent container configuration and startup scripts

* Rewrite proxy Dockerfile:

* ARCH used to be hard-coded; is now set according to the architecture being built
* Build from the associated LedgerSMB base image (not from 'lsmb-split')
* More deletion of non-required files (/usr/share/doc/*)
* Fewer layers by combining RUN commands

* Use 'server-start' script generated by the installer instead of repeating ourselves

* Don't expose the status module

It won't be accessible anyway: the localhost address is the one inside the container...

* Ensure relative redirects

When the container port :80 is exposed as :8080 on the host,
nginx redirects to http://localhost:80/login.pl with a relative
path, instead of http://localhost:8080/login.pl; the container
isn't bound to :80, so that request fails...

* Rename proxy layer image

* Adjust 'build' script to publish base and regular images

---------

Co-authored-by: Walid Mujahid <walidmujahid@gmail.com>

base/nginx.conf

@@ -0,0 +1,81 @@
+# This is a full (minimal) nginx configuration file
+
+error_log /dev/stderr info;
+pid /tmp/nginx.pid;
+worker_processes 1;
+
+events {
+   worker_connections 1024;
+}
+
+http {
+   client_body_temp_path /tmp/client_body;
+   proxy_temp_path /tmp/proxy_temp;
+   fastcgi_temp_path /tmp/fastcgi_temp;
+   scgi_temp_path /tmp/scgi_temp;
+   uwsgi_temp_path /tmp/uwsgi_temp;
+
+   sendfile on;
+   tcp_nopush on;
+   tcp_nodelay on;
+   keepalive_timeout 65;
+   types_hash_max_size 2048;
+   include /etc/nginx/mime.types;
+   default_type application/octet-stream;
+
+   access_log /dev/stdout;
+   error_log /dev/stderr info;
+
+   gzip off;
+   gzip_static on;
+
+   server {
+      listen 8080 default_server;
+      listen [::]:8080 default_server ipv6only=on;
+
+      root /srv/ledgersmb/UI;
+
+      access_log /dev/stdout;
+      error_log /dev/stderr info;
+
+      # Don't log status polls
+      location /nginx_status {
+               stub_status on;
+               access_log off;
+               allow 127.0.0.1;
+               allow ::1;
+               deny all;
+      }
+
+      # Configuration files don't exist
+      location ^~ \.conf$ {
+         return 404;
+      }
+
+      # 'Hidden' files don't exist
+      location ~ /\. {
+         return 404;
+      }
+
+      location = / {
+         return 301 /login.pl;
+      }
+
+      # JS & CSS
+      location ~* \.(js|css)$ {
+         add_header Pragma "public";
+         add_header Cache-Control "public, must-revalidate, proxy-revalidate"; # Production
+         expires     7d; # Indicate that the resource can be cached for 1 week # Production
+         try_files $uri =404;
+      }
+
+      location / {
+         proxy_set_header        Host $host;
+         proxy_set_header        X-Real-IP $remote_addr;
+         proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
+         proxy_set_header        X-Forwarded-Proto $scheme;
+         proxy_read_timeout      300;
+         proxy_pass              http://lsmb:5762;
+      }
+   }
+}