NixOS module: static files

Provided as NixOS config option and custom systemd unit directive.

Add a default param for git_version to make it work when the .git dir is
missing, for example when using the Github tarball.

static_files.nix uses the version from pyproject.toml as default.

nix/git_version.nix

@@ -1,12 +1,19 @@
-{ pkgs }:
+{ pkgs, default ? "unknown" }:
+
 with builtins;
 with pkgs;
 
-lib.replaceStrings
-  ["\n"]
-  [""]
-  (lib.readFile
-    (runCommand
-      "git-version"
-      { src = ../.; buildInputs = [ gitMinimal ]; }
-      "cd $src; git describe --long --tags --dirty --always > $out"))
+let
+  gitVersion =
+    lib.replaceStrings
+      ["\n"]
+      [""]
+      (lib.readFile
+        (runCommand
+          "git-version"
+          { src = ../.; buildInputs = [ gitMinimal ]; }
+          "cd $src; git describe --long --tags --dirty --always > $out"));
+in
+  if pathExists ../.git
+  then gitVersion
+  else default

nix/modules/default.nix

@@ -71,6 +71,12 @@ in {
       default = null;
     };
 
+    staticFiles = mkOption {
+      internal = true;
+      type = with types; nullOr path;
+      default = null;
+    };
+
     browserSessionSecretKeyFile = mkOption {
       type = types.str;
       description = "Path to file containing the secret key for browser session signing";
@@ -101,6 +107,7 @@ in {
   config = lib.mkIf cfg.enable {
 
     services.ekklesia.portal.configFile = configInput;
+    services.ekklesia.portal.staticFiles = staticFiles;
 
     environment.systemPackages = [ ekklesiaPortalConfig ekklesiaPortalShowConfig ];
 
@@ -146,6 +153,7 @@ in {
         Restart = "always";
         X-ConfigFile = configInput;
         X-ServeApp = serveApp;
+        X-StaticFiles = staticFiles;
 
         DeviceAllow = [
           "/dev/stderr"

nix/static_files.nix

@@ -1,8 +1,10 @@
+with builtins;
+
 { sources ? null }:
 let
   deps = import ./deps.nix { inherit sources; };
-  inherit (deps) lib pkgs sassc javascriptDeps webfontsPath sassPath deform python;
-  version = import ./git_version.nix { inherit pkgs; };
+  inherit (deps) lib pkgs sassc javascriptDeps webfontsPath sassPath deform python pyProject;
+  version = import ./git_version.nix { inherit pkgs; default = pyProject.tool.poetry.version; };
 
 in
 pkgs.runCommand "ekklesia-portal-static-${version}" {