From 3aa9692beb99d6fa0016e99629fbf1f1ed4ec6b2 Mon Sep 17 00:00:00 2001
From: Christian Kampka <christian@kampka.net>
Date: Sat, 3 Jul 2021 08:29:59 +0100
Subject: [PATCH 1/3] coturn: Support secrets file for configuring the
 static-auth-secret

---
 nixos/modules/services/networking/coturn.nix | 97 +++++++++++++-------
 1 file changed, 63 insertions(+), 34 deletions(-)

diff --git a/nixos/modules/services/networking/coturn.nix b/nixos/modules/services/networking/coturn.nix
index 1bfbc307c59d..5f7d2893ae27 100644
--- a/nixos/modules/services/networking/coturn.nix
+++ b/nixos/modules/services/networking/coturn.nix
@@ -16,6 +16,7 @@ ${lib.optionalString cfg.lt-cred-mech "lt-cred-mech"}
 ${lib.optionalString cfg.no-auth "no-auth"}
 ${lib.optionalString cfg.use-auth-secret "use-auth-secret"}
 ${lib.optionalString (cfg.static-auth-secret != null) ("static-auth-secret=${cfg.static-auth-secret}")}
+${lib.optionalString (cfg.static-auth-secret-file != null) ("static-auth-secret=#static-auth-secret#")}
 realm=${cfg.realm}
 ${lib.optionalString cfg.no-udp "no-udp"}
 ${lib.optionalString cfg.no-tcp "no-tcp"}
@@ -182,6 +183,13 @@ in {
           by a separate program, so this is why that other mode is 'dynamic'.
         '';
       };
+      static-auth-secret-file = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          Path to the file containing the static authentication secret.
+        '';
+      };
       realm = mkOption {
         type = types.str;
         default = config.networking.hostName;
@@ -293,42 +301,63 @@ in {
     };
   };
 
-  config = mkIf cfg.enable {
-    users.users.turnserver =
-      { uid = config.ids.uids.turnserver;
-        description = "coturn TURN server user";
-      };
-    users.groups.turnserver =
-      { gid = config.ids.gids.turnserver;
-        members = [ "turnserver" ];
-      };
+  config = mkIf cfg.enable (mkMerge ([
+    { assertions = [
+      { assertion = cfg.static-auth-secret != null -> cfg.static-auth-secret-file == null ;
+        message = "static-auth-secret and static-auth-secret-file cannot be set at the same time";
+      }
+    ];}
 
-    systemd.services.coturn = {
-      description = "coturn TURN server";
-      after = [ "network-online.target" ];
-      wants = [ "network-online.target" ];
-      wantedBy = [ "multi-user.target" ];
+    {
+      users.users.turnserver =
+        { uid = config.ids.uids.turnserver;
+          description = "coturn TURN server user";
+        };
+      users.groups.turnserver =
+        { gid = config.ids.gids.turnserver;
+          members = [ "turnserver" ];
+        };
 
-      unitConfig = {
-        Documentation = "man:coturn(1) man:turnadmin(1) man:turnserver(1)";
-      };
+      systemd.services.coturn = let
+        runConfig = "/run/coturn/turnserver.cfg";
+      in {
+        description = "coturn TURN server";
+        after = [ "network-online.target" ];
+        wants = [ "network-online.target" ];
+        wantedBy = [ "multi-user.target" ];
 
-      serviceConfig = {
-        Type = "simple";
-        ExecStart = "${pkgs.coturn}/bin/turnserver -c ${configFile}";
-        RuntimeDirectory = "turnserver";
-        User = "turnserver";
-        Group = "turnserver";
-        AmbientCapabilities =
-          mkIf (
-            cfg.listening-port < 1024 ||
-            cfg.alt-listening-port < 1024 ||
-            cfg.tls-listening-port < 1024 ||
-            cfg.alt-tls-listening-port < 1024 ||
-            cfg.min-port < 1024
-          ) "cap_net_bind_service";
-        Restart = "on-abort";
+        unitConfig = {
+          Documentation = "man:coturn(1) man:turnadmin(1) man:turnserver(1)";
+        };
+
+        preStart = ''
+          cat ${configFile} > ${runConfig}
+          ${optionalString (cfg.static-auth-secret-file != null) ''
+            STATIC_AUTH_SECRET="$(head -n1 ${cfg.static-auth-secret-file} || :)"
+            sed -e "s,#static-auth-secret#,$STATIC_AUTH_SECRET,g" \
+              -i ${runConfig}
+          '' }
+          chmod 640 ${runConfig}
+        '';
+        serviceConfig = {
+          Type = "simple";
+          ExecStart = "${pkgs.coturn}/bin/turnserver -c ${runConfig}";
+          RuntimeDirectory = "turnserver";
+          User = "turnserver";
+          Group = "turnserver";
+          AmbientCapabilities =
+            mkIf (
+              cfg.listening-port < 1024 ||
+              cfg.alt-listening-port < 1024 ||
+              cfg.tls-listening-port < 1024 ||
+              cfg.alt-tls-listening-port < 1024 ||
+              cfg.min-port < 1024
+            ) "cap_net_bind_service";
+          Restart = "on-abort";
+        };
       };
-    };
-  };
+    systemd.tmpfiles.rules = [
+      "d  /run/coturn 0700 turnserver turnserver - -"
+    ];
+  }]));
 }

From 971e37dc07266ae61104e3a246cdfd81e867f089 Mon Sep 17 00:00:00 2001
From: Christian Kampka <christian@kampka.net>
Date: Sat, 3 Jul 2021 08:32:03 +0100
Subject: [PATCH 2/3] nixos/tests/coturn: init

Co-authored-by: MatthewCroughan <matt@croughan.sh>
---
 nixos/tests/all-tests.nix |  1 +
 nixos/tests/coturn.nix    | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 nixos/tests/coturn.nix

diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index b5126be8af7a..d18770859f26 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -88,6 +88,7 @@ in
   containers-tmpfs = handleTest ./containers-tmpfs.nix {};
   convos = handleTest ./convos.nix {};
   corerad = handleTest ./corerad.nix {};
+  coturn = handleTest ./coturn.nix {};
   couchdb = handleTest ./couchdb.nix {};
   cri-o = handleTestOn ["x86_64-linux"] ./cri-o.nix {};
   custom-ca = handleTest ./custom-ca.nix {};
diff --git a/nixos/tests/coturn.nix b/nixos/tests/coturn.nix
new file mode 100644
index 000000000000..dff832281c7c
--- /dev/null
+++ b/nixos/tests/coturn.nix
@@ -0,0 +1,29 @@
+import ./make-test-python.nix ({ ... }: {
+  name = "coturn";
+  nodes = {
+    default = {
+      services.coturn.enable = true;
+    };
+    secretsfile = {
+      boot.postBootCommands = ''
+        echo "some-very-secret-string" > /run/coturn-secret
+      '';
+      services.coturn = {
+        enable = true;
+        static-auth-secret-file = "/run/coturn-secret";
+      };
+    };
+  };
+
+  testScript =
+    ''
+      start_all()
+
+      with subtest("by default works without configuration"):
+          default.wait_for_unit("coturn.service")
+
+      with subtest("works with static-auth-secret-file"):
+          secretsfile.wait_for_unit("coturn.service")
+          secretsfile.succeed("grep 'some-very-secret-string' /run/coturn/turnserver.cfg")
+    '';
+})

From 5df1e9d93d98500129b5d0179721e7b6ba787707 Mon Sep 17 00:00:00 2001
From: matthewcroughan <matt@croughan.sh>
Date: Sat, 3 Jul 2021 08:33:39 +0100
Subject: [PATCH 3/3] coturn: add test for static-auth-secret-file

Adds passthru.tests.coturn = nixosTests.coturn;
---
 pkgs/servers/coturn/default.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkgs/servers/coturn/default.nix b/pkgs/servers/coturn/default.nix
index 73b1ba01844a..d076f763bf96 100644
--- a/pkgs/servers/coturn/default.nix
+++ b/pkgs/servers/coturn/default.nix
@@ -8,6 +8,7 @@
 , libprom
 , libpromhttp
 , libmicrohttpd
+, nixosTests
 }:
 
 stdenv.mkDerivation rec {
@@ -34,6 +35,8 @@ stdenv.mkDerivation rec {
     ./pure-configure.patch
   ];
 
+  passthru.tests.coturn = nixosTests.coturn;
+
   meta = with lib; {
     homepage = "https://coturn.net/";
     license = with licenses; [ bsd3 ];