nixos/middleman: Add nginx-sso

nixos/boxes/colony/vms/shill/containers/middleman/default.nix

@@ -45,12 +45,60 @@
                   owner = "acme";
                   group = "acme";
                 };
+                "nginx-sso.yaml" = {
+                  owner = "nginx-sso";
+                  group = "nginx-sso";
+                };
               };
             };
 
             firewall = {
               tcp.allowed = [ "http" "https" 8448 ];
             };
+
+            nginx-sso = {
+              enable = true;
+              extraConfigFile = config.age.secrets."nginx-sso.yaml".path;
+              configuration = {
+                listen = {
+                  addr = "[::]";
+                  port = 8082;
+                };
+                login = {
+                  title = "${lib.my.pubDomain} login";
+                  default_redirect = "https://${lib.my.pubDomain}";
+                  default_method = "google_oauth";
+                  names = {
+                    google_oauth = "Google account";
+                  };
+                };
+                cookie = {
+                  domain = ".${lib.my.pubDomain}";
+                  secure = true;
+                };
+                audit_log = {
+                  targets = [ "fd://stdout" ];
+                  events  = [
+                    "access_denied"
+                    "login_success"
+                    "login_failure"
+                    "logout"
+                    #"validate"
+                  ];
+                };
+                providers = {
+                  google_oauth = {
+                    client_id = "545475967061-cag4g1qf0pk33g3pdbom4v69562vboc8.apps.googleusercontent.com";
+                    redirect_url = "https://sso.${lib.my.pubDomain}/login";
+                    user_id_method = "user-id";
+                  };
+                };
+              };
+              includes = {
+                endpoint = "http://localhost:8082";
+                baseURL = "https://sso.${lib.my.pubDomain}";
+              };
+            };
           };
 
           users = {
@@ -167,7 +215,9 @@
                 proxy_http_version 1.1;
 
                 # proxy headers
+                proxy_set_header X-Origin-URI $request_uri;
                 proxy_set_header Host $host;
+                proxy_set_header X-Host $http_host;
                 proxy_set_header X-Forwarded-Host $http_host;
                 proxy_set_header X-Forwarded-Server $host;
                 proxy_set_header X-Real-IP $remote_addr;

nixos/boxes/colony/vms/shill/containers/middleman/vhosts.nix

@@ -6,6 +6,17 @@ let
   dualStackListen' = l: map (addr: l // { inherit addr; }) [ "0.0.0.0" "[::]" ];
   dualStackListen = ll: flatten (map dualStackListen' ll);
 
+  ssoServer = i: {
+    extraConfig = ''
+      include /etc/nginx/includes/sso/server-${i}.conf;
+    '';
+  };
+  ssoLoc = i: {
+    extraConfig = ''
+      include /etc/nginx/includes/sso/location-${i}.conf;
+    '';
+  };
+
   mkWellKnown = type: content: pkgs.writeTextFile {
     name = "well-known-${type}";
     destination = "/${type}";
@@ -34,6 +45,12 @@ let
   };
 in
 {
+  my = {
+    nginx-sso.includes.instances = {
+      generic = {};
+    };
+  };
+
   services.nginx.virtualHosts =
   let
     hosts = {
@@ -47,7 +64,12 @@ in
         ];
       };
 
-      "pass.nul.ie" =
+      "sso.${lib.my.pubDomain}" = {
+        locations."/".proxyPass = config.my.nginx-sso.includes.endpoint;
+        useACMEHost = lib.my.pubDomain;
+      };
+
+      "pass.${lib.my.pubDomain}" =
       let
         upstream = "http://vaultwarden-ctr.${config.networking.domain}";
       in
@@ -79,14 +101,14 @@ in
         locations = mkMerge [
           {
             "/".proxyPass = "http://chatterbox-ctr.${config.networking.domain}:8008";
-            "= /".return = "301 https://element.nul.ie";
+            "= /".return = "301 https://element.${lib.my.pubDomain}";
           }
           wellKnown
         ];
         useACMEHost = lib.my.pubDomain;
       };
 
-      "element.nul.ie" =
+      "element.${lib.my.pubDomain}" =
       let
         headers = ''
           add_header X-Frame-Options SAMEORIGIN;

nixos/modules/_list.nix

@@ -13,5 +13,6 @@
     vms = ./vms.nix;
     network = ./network.nix;
     pdns = ./pdns.nix;
+    nginx-sso = ./nginx-sso.nix;
   };
 }

nixos/modules/network.nix

@@ -35,7 +35,7 @@ in
   config = mkMerge [
     {
       networking = {
-        domain = mkDefault "int.nul.ie";
+        domain = mkDefault "int.${lib.my.pubDomain}";
         useDHCP = false;
         enableIPv6 = mkDefault true;
         useNetworkd = mkDefault true;

nixos/modules/nginx-sso.nix

@@ -0,0 +1,127 @@
+{ lib, pkgs, config, ... }:
+let
+  inherit (lib) mkIf mkMerge getBin mapAttrsToList;
+  inherit (lib.my) mkOpt' mkBoolOpt';
+
+  includeOpts = { ... }: {
+    options = with lib.types; {
+      auth = {
+        path = mkOpt' str "/sso-auth" "HTTP path for SSO auth.";
+        redirect = mkOpt' str "$scheme://$http_host$request_uri" "URL to redirect to upon successful login.";
+      };
+      logout = {
+        path = mkOpt' str "/sso-logout" "HTTP path for SSO logout.";
+        redirect = mkOpt' str "$scheme://$http_host/" "URL to redirect to upon successful logout.";
+      };
+    };
+  };
+
+  cfg = config.my.nginx-sso;
+
+  pkg = getBin cfg.package;
+  baseConfig = pkgs.writeText "nginx-sso.yaml" (builtins.toJSON cfg.configuration);
+  runCfg = "/run/nginx-sso/config.yaml";
+in
+{
+  options.my.nginx-sso = with lib.types; {
+    enable = mkBoolOpt' true "Whether to enable custom nginx-sso.";
+    package = mkOpt' package pkgs.nginx-sso "nginx-sso package to use.";
+    configuration = mkOpt' (attrsOf unspecified) { } "nginx-sso configuration.";
+    extraConfigFile = mkOpt' (nullOr str) null "Path to configuration (e.g. for secrets).";
+
+    includes = {
+      endpoint = mkOpt' str "http://localhost:8082" "Upstream for proxied auth requests.";
+      baseURL = mkOpt' str null "Base URL for redirects.";
+
+      instances = mkOpt' (attrsOf (submodule includeOpts)) { } "nginx includes instances.";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = !config.services.nginx.sso.enable;
+        message = "Stock nginx-sso cannot be used with this module.";
+      }
+    ];
+
+    environment.etc = with cfg.includes; mkMerge (mapAttrsToList (n: i: {
+        "nginx/includes/sso/server-${n}.conf".text = ''
+          location ${i.auth.path} {
+            # Do not allow requests from outside
+            internal;
+
+            # Access /auth endpoint to query login state
+            proxy_pass ${endpoint}/auth;
+
+            # Do not forward the request body (nginx-sso does not care about it)
+            proxy_pass_request_body off;
+            proxy_set_header Content-Length "";
+
+            # Set custom information for ACL matching: Each one is available as
+            # a field for matching: X-Host = x-host, ...
+            proxy_set_header X-Origin-URI $request_uri;
+            proxy_set_header X-Host $http_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;
+          }
+
+          # Define where to send the user to login and specify how to get back
+          location @error401 {
+            return 302 ${baseURL}/login?go=${i.auth.redirect};
+          }
+
+          # If the user is lead to /logout redirect them to the logout endpoint
+          # of ngninx-sso which then will redirect the user to / on the current host
+          location ${i.logout.path} {
+            return 302 ${baseURL}/logout?go=${i.logout.redirect};
+          }
+        '';
+        "nginx/includes/sso/location-${n}.conf".text = ''
+          # Protect this location using the auth_request
+          auth_request ${i.auth.path};
+
+          # Redirect the user to the login page when they are not logged in
+          error_page 401 = @error401;
+
+          # Automatically renew SSO cookie on request
+          auth_request_set $cookie $upstream_http_set_cookie;
+          add_header Set-Cookie $cookie;
+        '';
+      }) instances);
+
+    users = {
+      groups.nginx-sso = {};
+      users.nginx-sso = {
+        group = "nginx-sso";
+        isSystemUser = true;
+      };
+    };
+
+    systemd.services.nginx-sso = {
+      description = "Nginx SSO Backend";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+
+      preStart = ''
+        umask 066
+      ${if (cfg.extraConfigFile != null) then ''
+        ${pkgs.yq-go}/bin/yq -P '. *= load("${cfg.extraConfigFile}")' "${baseConfig}" > ${runCfg}
+      '' else ''
+        ${pkgs.yq-go}/bin/yq -P "${baseConfig}" > ${runCfg}
+      ''}
+      '';
+      serviceConfig = {
+        RuntimeDirectory = "nginx-sso";
+        User = "nginx-sso";
+        Group = "nginx-sso";
+        ExecStart = [
+          # Specify twice to clear original value
+          ""
+          ''${pkg}/bin/nginx-sso --frontend-dir ${pkg}/share/frontend --config ${runCfg}''
+        ];
+      };
+    };
+  };
+}