nixos/nextcloud: add secrets option

Uses existing `nix_read_secret` and LoadCredential to read contents of a
file into an entry in `config.php`

nixos/modules/services/web-apps/nextcloud.nix

@@ -120,7 +120,8 @@ let
     ++ (lib.optional (
       cfg.config.objectstore.s3.sseCKeyFile != null
     ) "s3_sse_c_key:${cfg.config.objectstore.s3.sseCKeyFile}")
-    ++ (lib.optional (cfg.secretFile != null) "secret_file:${cfg.secretFile}");
+    ++ (lib.optional (cfg.secretFile != null) "secret_file:${cfg.secretFile}")
+    ++ (lib.mapAttrsToList (credential: file: "${credential}:${file}") cfg.secrets);
 
   requiresRuntimeSystemdCredentials = (lib.length runtimeSystemdCredentials) != 0;
 
@@ -296,6 +297,9 @@ let
         ) "'dbtableprefix' => '${toString c.dbtableprefix}',"}
         ${lib.optionalString (c.dbpassFile != null) "'dbpassword' => nix_read_secret('dbpass'),"}
         'dbtype' => '${c.dbtype}',
+        ${lib.concatStringsSep "\n" (
+          lib.mapAttrsToList (name: credential: "'${name}' => nix_read_secret('${name}'),") cfg.secrets
+        )}
         ${objectstoreConfig}
       ];
 
@@ -390,6 +394,24 @@ in
       '';
       example = "/mnt/nextcloud-file";
     };
+    secrets = lib.mkOption {
+      type = lib.types.attrsOf (
+        lib.types.pathWith {
+          inStore = false;
+          absolute = true;
+        }
+      );
+      default = { };
+      description = ''
+        Secret files to read into entries in `config.php`.
+        This uses `nix_read_secret` and LoadCredential to read the contents of the file into the entry in `config.php`.
+      '';
+      example = lib.literalExpression ''
+        {
+          oidc_login_client_secret = "/run/secrets/nextcloud_oidc_secret";
+        }
+      '';
+    };
     extraApps = lib.mkOption {
       type = lib.types.attrsOf lib.types.package;
       default = { };

nixos/tests/nextcloud/basic.nix

@@ -63,8 +63,11 @@ runTest (
             };
             phpExtraExtensions = all: [ all.bz2 ];
             nginx.enableFastcgiRequestBuffering = true;
+            secrets.mysecret = "/etc/nextcloud/mysecretfile";
           };
 
+          environment.etc."nextcloud/mysecretfile".text = "foobar";
+
           specialisation.withoutMagick.configuration = {
             services.nextcloud.enableImagemagick = false;
           };
@@ -116,6 +119,9 @@ runTest (
             client_hash = client.succeed("nix-hash testfile.bin").strip()
             nextcloud_hash = nextcloud.succeed("nix-hash /var/lib/nextcloud-data/data/root/files/testfile.bin").strip()
             t.assertEqual(client_hash, nextcloud_hash)
+
+        with subtest("secrets"):
+            assert "foobar" == nextcloud.succeed("nextcloud-occ config:system:get mysecret").strip()
       '';
   }
 )