Merge pull request #163009 from scvalex/nbd-service

nbd: add nbd service and test

2 files changed, 88 insertions, 0 deletions

diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 15b54cd9fe1..043d8a56d0c 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -329,6 +329,7 @@ in
   nat.standalone = handleTest ./nat.nix { withFirewall = false; };
   nats = handleTest ./nats.nix {};
   navidrome = handleTest ./navidrome.nix {};
+  nbd = handleTest ./nbd.nix {};
   ncdns = handleTest ./ncdns.nix {};
   ndppd = handleTest ./ndppd.nix {};
   nebula = handleTest ./nebula.nix {};
diff --git a/nixos/tests/nbd.nix b/nixos/tests/nbd.nix
new file mode 100644
index 00000000000..16255e68e8a
--- /dev/null
+++ b/nixos/tests/nbd.nix
@@ -0,0 +1,87 @@
+import ./make-test-python.nix ({ pkgs, ... }:
+  let
+    listenPort = 30123;
+    testString = "It works!";
+    mkCreateSmallFileService = { path, loop ? false }: {
+      script = ''
+        ${pkgs.coreutils}/bin/dd if=/dev/zero of=${path} bs=1K count=100
+        ${pkgs.lib.optionalString loop
+          "${pkgs.util-linux}/bin/losetup --find ${path}"}
+      '';
+      serviceConfig = {
+        Type = "oneshot";
+      };
+      wantedBy = [ "multi-user.target" ];
+      before = [ "nbd-server.service" ];
+    };
+  in
+  {
+    name = "nbd";
+
+    nodes = {
+      server = { config, pkgs, ... }: {
+        # Create some small files of zeros to use as the ndb disks
+        ## `vault-pub.disk` is accessible from any IP
+        systemd.services.create-pub-file =
+          mkCreateSmallFileService { path = "/vault-pub.disk"; };
+        ## `vault-priv.disk` is accessible only from localhost.
+        ## It's also a loopback device to test exporting /dev/...
+        systemd.services.create-priv-file =
+          mkCreateSmallFileService { path = "/vault-priv.disk"; loop = true; };
+
+        # Needed only for nbd-client used in the tests.
+        environment.systemPackages = [ pkgs.nbd ];
+
+        # Open the nbd port in the firewall
+        networking.firewall.allowedTCPPorts = [ listenPort ];
+
+        # Run the nbd server and expose the small file created above
+        services.nbd.server = {
+          enable = true;
+          exports = {
+            vault-pub = {
+              path = "/vault-pub.disk";
+            };
+            vault-priv = {
+              path = "/dev/loop0";
+              allowAddresses = [ "127.0.0.1" "::1" ];
+            };
+          };
+          listenAddress = "0.0.0.0";
+          listenPort = listenPort;
+        };
+      };
+
+      client = { config, pkgs, ... }: {
+        programs.nbd.enable = true;
+      };
+    };
+
+    testScript = ''
+      testString = "${testString}"
+
+      start_all()
+      server.wait_for_open_port(${toString listenPort})
+
+      # Client: Connect to the server, write a small string to the nbd disk, and cleanly disconnect
+      client.succeed("nbd-client server ${toString listenPort} /dev/nbd0 -name vault-pub -persist")
+      client.succeed(f"echo '{testString}' | dd of=/dev/nbd0 conv=notrunc")
+      client.succeed("nbd-client -d /dev/nbd0")
+
+      # Server: Check that the string written by the client is indeed in the file
+      foundString = server.succeed(f"dd status=none if=/vault-pub.disk count={len(testString)}")[:len(testString)]
+      if foundString != testString:
+         raise Exception(f"Read the wrong string from nbd disk. Expected: '{testString}'. Found: '{foundString}'")
+
+      # Client: Fail to connect to the private disk
+      client.fail("nbd-client server ${toString listenPort} /dev/nbd0 -name vault-priv -persist")
+
+      # Server: Successfully connect to the private disk
+      server.succeed("nbd-client localhost ${toString listenPort} /dev/nbd0 -name vault-priv -persist")
+      server.succeed(f"echo '{testString}' | dd of=/dev/nbd0 conv=notrunc")
+      foundString = server.succeed(f"dd status=none if=/dev/loop0 count={len(testString)}")[:len(testString)]
+      if foundString != testString:
+         raise Exception(f"Read the wrong string from nbd disk. Expected: '{testString}'. Found: '{foundString}'")
+      server.succeed("nbd-client -d /dev/nbd0")
+    '';
+  })