init: syncthing module

Assumes one `introducer` peer, which can AutoShare configured folders,
with peers that know the `deviceID` of the introducer.

checks/syncthing/default.nix

@@ -0,0 +1,108 @@
+(import ../lib/test-base.nix) (
+  # Using nixos-test, because our own test system doesn't support the necessary
+  # features for systemd.
+  { lib, ... }:
+  {
+    name = "syncthing";
+
+    nodes.introducer =
+      { self, ... }:
+      {
+        imports = [
+          self.clanModules.syncthing
+          self.nixosModules.clanCore
+          {
+            clanCore.machineName = "introducer";
+            clanCore.clanDir = ./.;
+            environment.etc = {
+              "syncthing.pam".source = ./introducer/introducer_test_cert;
+              "syncthing.key".source = ./introducer/introducer_test_key;
+              "syncthing.api".source = ./introducer/introducer_test_api;
+            };
+            clanCore.secrets.syncthing.secrets."syncthing.api".path = "/etc/syncthing.api";
+            services.syncthing.cert = "/etc/syncthing.pam";
+            services.syncthing.key = "/etc/syncthing.key";
+            # Doesn't test zerotier!
+            services.syncthing.openDefaultPorts = true;
+            services.syncthing.settings.folders = {
+              "Shared" = {
+                enable = true;
+                path = "~/Shared";
+                versioning = {
+                  type = "trashcan";
+                  params = {
+                    cleanoutDays = "30";
+                  };
+                };
+              };
+            };
+            clan.syncthing.autoAcceptDevices = true;
+            clan.syncthing.autoShares = [ "Shared" ];
+            # For faster Tests
+            systemd.timers.syncthing-auto-accept.timerConfig = {
+              OnActiveSec = 1;
+              OnUnitActiveSec = 1;
+            };
+          }
+        ];
+      };
+    nodes.peer1 =
+      { self, ... }:
+      {
+        imports = [
+          self.clanModules.syncthing
+          self.nixosModules.clanCore
+          {
+            clanCore.machineName = "peer1";
+            clanCore.clanDir = ./.;
+            clan.syncthing.introducer = lib.strings.removeSuffix "\n" (
+              builtins.readFile ./introducer/introducer_device_id
+            );
+            environment.etc = {
+              "syncthing.pam".source = ./peer_1/peer_1_test_cert;
+              "syncthing.key".source = ./peer_1/peer_1_test_key;
+            };
+            services.syncthing.openDefaultPorts = true;
+            services.syncthing.cert = "/etc/syncthing.pam";
+            services.syncthing.key = "/etc/syncthing.key";
+          }
+        ];
+      };
+    nodes.peer2 =
+      { self, ... }:
+      {
+        imports = [
+          self.clanModules.syncthing
+          self.nixosModules.clanCore
+          {
+            clanCore.machineName = "peer2";
+            clanCore.clanDir = ./.;
+            clan.syncthing.introducer = lib.strings.removeSuffix "\n" (
+              builtins.readFile ./introducer/introducer_device_id
+            );
+            environment.etc = {
+              "syncthing.pam".source = ./peer_2/peer_2_test_cert;
+              "syncthing.key".source = ./peer_2/peer_2_test_key;
+            };
+            services.syncthing.openDefaultPorts = true;
+            services.syncthing.cert = "/etc/syncthing.pam";
+            services.syncthing.key = "/etc/syncthing.key";
+          }
+        ];
+      };
+    testScript = ''
+      start_all()
+      introducer.wait_for_unit("syncthing")
+      peer1.wait_for_unit("syncthing")
+      peer2.wait_for_unit("syncthing")
+      peer1.wait_for_file("/home/user/Shared")
+      peer2.wait_for_file("/home/user/Shared")
+      introducer.shutdown()
+      peer1.execute("echo hello > /home/user/Shared/hello")
+      peer2.wait_for_file("/home/user/Shared/hello")
+      out = peer2.succeed("cat /home/user/Shared/hello")
+      print(out)
+      assert "hello" in out
+    '';
+  }
+)