A new start

lib/network/default.nix

@@ -0,0 +1,54 @@
+{ lib, inputs, snowfall-inputs }:
+
+let
+  inherit (inputs.nixpkgs.lib) assertMsg last;
+in
+{
+  network = {
+    # Split an address to get its host name or ip and its port.
+    # Type: String -> Attrs
+    # Usage: get-address-parts "bismuth:3000"
+    #   result: { host = "bismuth"; port = "3000"; }
+    get-address-parts = address:
+      let
+        address-parts = builtins.split ":" address;
+        ip = builtins.head address-parts;
+        host = if ip == "" then "127.0.0.1" else ip;
+        port = if builtins.length address-parts != 3 then "" else last address-parts;
+      in
+      { inherit host port; };
+
+    ## Create proxy configuration for NGINX virtual hosts.
+    ##
+    ## ```nix
+    ## services.nginx.virtualHosts."example.com" = lib.network.create-proxy {
+    ##   port = 3000;
+    ##   host = "0.0.0.0";
+    ##   proxy-web-sockets = true;
+    ##   extra-config = {
+    ##     forceSSL = true;
+    ##   };
+    ## }
+    ## ``
+    ##
+    #@ { port: Int ? null, host: String ? "127.0.0.1", proxy-web-sockets: Bool ? false, extra-config: Attrs ? { } } -> Attrs
+    create-proxy =
+      { port ? null
+      , host ? "127.0.0.1"
+      , proxy-web-sockets ? false
+      , extra-config ? { }
+      }:
+        assert assertMsg (port != "" && port != null) "port cannot be empty";
+        assert assertMsg (host != "") "host cannot be empty";
+        extra-config // {
+          locations = (extra-config.locations or { }) // {
+            "/" = (extra-config.locations."/" or { }) // {
+              proxyPass =
+                "http://${host}${if port != null then ":${builtins.toString port}" else ""}";
+
+              proxyWebsockets = proxy-web-sockets;
+            };
+          };
+        };
+  };
+}