feat(nix): add nginx reverse proxy to web-servers module

Adds nginx reverse proxy functionality with SSL support.

nix/manifest.nix

@@ -40,6 +40,19 @@
           };
           web-servers = {
             enableSSL = true;
+            nginx = {
+              enable = true;
+              proxies = [
+                {
+                  source = "aenyrathia.wiki";
+                  target = "http://helios:5896";
+                }
+                {
+                  source = "il.bwfiq.com";
+                  target = "http://helios:2283";
+                }
+              ];
+            };
           };
           databases = {
             mongodb.enable = true;

nix/modules/server/web-servers.nix

@@ -15,10 +15,54 @@ in
     { config, ... }:
     let
       cfg = config.server.web-servers;
+      sslCheck = good: bad: if cfg.enableSSL then good else bad;
     in
     {
       options.server.web-servers = {
         enableSSL = mkEnableOption "";
+        nginx = {
+          enable = mkEnableOption "the Nginx server";
+          openFirewall = mkEnableOption "" // {
+            default = true;
+          };
+          enableDefaultSink = mkEnableOption "" // {
+            default = true;
+          };
+          pages = mkOption {
+            default = [ ];
+            type = listOf (submodule {
+              options = {
+                domain = mkStrOption "";
+                root = mkPathOption "";
+                extraConfig = mkOption {
+                  type = attrs;
+                  default = { };
+                };
+                locations = mkOption {
+                  type = attrs;
+                  default = { };
+                };
+              };
+            });
+          };
+          proxies = mkOption {
+            default = [ ];
+            type = listOf (submodule {
+              options = {
+                source = mkStrOption "";
+                target = mkStrOption "";
+                extraConfig = mkOption {
+                  type = attrs;
+                  default = { };
+                };
+                locations = mkOption {
+                  type = attrs;
+                  default = { };
+                };
+              };
+            });
+          };
+        };
       };
       config = mkMerge [
         (mkIf cfg.enableSSL {
@@ -38,6 +82,61 @@ in
             };
           };
         })
+        (mkIf cfg.nginx.enable {
+          networking.firewall.allowedTCPPorts = mkIf cfg.nginx.openFirewall [
+            443
+            80
+          ];
+          users.users.nginx.extraGroups = singleton "acme";
+          services.nginx = {
+            enable = true;
+            recommendedProxySettings = true;
+            recommendedTlsSettings = true;
+            recommendedOptimisation = true;
+            recommendedGzipSettings = true;
+            virtualHosts = mkMerge [
+              (mkIf cfg.nginx.enableDefaultSink {
+                "_" = {
+                  default = true;
+                  rejectSSL = sslCheck true false;
+                  locations."/" = {
+                    return = "444";
+                  };
+                };
+              })
+              (listToAttrs (
+                map (page: {
+                  name = page.domain;
+                  value = {
+                    addSSL = sslCheck true false;
+                    useACMEHost = sslCheck (mkRootDomain page.domain) null;
+                    acmeRoot = null; # needed for DNS validation
+                    locations = {
+                      "/" = {
+                        inherit (page) root;
+                      } // page.extraConfig;
+                    } // page.locations;
+                  };
+                }) cfg.nginx.pages
+              ))
+              (listToAttrs (
+                map (proxy: {
+                  name = proxy.source;
+                  value = {
+                    addSSL = sslCheck true false;
+                    useACMEHost = sslCheck (mkRootDomain proxy.source) null;
+                    acmeRoot = null; # needed for DNS validation
+                    locations = {
+                      "/" = {
+                        proxyPass = proxy.target;
+                      } // proxy.extraConfig;
+                    } // proxy.locations;
+                  };
+                }) cfg.nginx.proxies
+              ))
+            ];
+          };
+        })
       ];
     };
 }