nixos/opentelemetry-collector: add nixosTest

(cherry picked from commit a45a1a51e57eff974922b19d80b77ff0c23771f0)
Signed-off-by: Domen Kožar <domen@dev.si>

nixos/tests/all-tests.nix

@@ -506,6 +506,7 @@ in {
   openstack-image-metadata = (handleTestOn ["x86_64-linux"] ./openstack-image.nix {}).metadata or {};
   openstack-image-userdata = (handleTestOn ["x86_64-linux"] ./openstack-image.nix {}).userdata or {};
   opentabletdriver = handleTest ./opentabletdriver.nix {};
+  opentelemetry-collector = handleTest ./opentelemetry-collector.nix {};
   owncast = handleTest ./owncast.nix {};
   image-contents = handleTest ./image-contents.nix {};
   orangefs = handleTest ./orangefs.nix {};

nixos/tests/opentelemetry-collector.nix

@@ -0,0 +1,76 @@
+import ./make-test-python.nix ({ pkgs, ...} : let
+  port = 4318;
+in {
+  name = "opentelemetry-collector";
+  meta = with pkgs.lib.maintainers; {
+    maintainers = [ tylerjl ];
+  };
+
+  nodes.machine = { ... }: {
+    networking.firewall.allowedTCPPorts = [ port ];
+    services.opentelemetry-collector = {
+      enable = true;
+      settings = {
+        exporters.logging.verbosity = "detailed";
+        receivers.otlp.protocols.http = {};
+        service = {
+          pipelines.logs = {
+            receivers = [ "otlp" ];
+            exporters = [ "logging" ];
+          };
+        };
+      };
+    };
+    virtualisation.forwardPorts = [{
+      host.port = port;
+      guest.port = port;
+    }];
+  };
+
+  extraPythonPackages = p: [
+    p.requests
+    p.types-requests
+  ];
+
+  # Send a log event through the OTLP pipeline and check for its
+  # presence in the collector logs.
+  testScript = /* python */ ''
+    import requests
+    import time
+
+    from uuid import uuid4
+
+    flag = str(uuid4())
+
+    machine.wait_for_unit("opentelemetry-collector.service")
+    machine.wait_for_open_port(${toString port})
+
+    event = {
+        "resourceLogs": [
+            {
+                "resource": {"attributes": []},
+                "scopeLogs": [
+                    {
+                        "logRecords": [
+                            {
+                                "timeUnixNano": str(time.time_ns()),
+                                "severityNumber": 9,
+                                "severityText": "Info",
+                                "name": "logTest",
+                                "body": {
+                                    "stringValue": flag
+                                },
+                                "attributes": []
+                            },
+                        ]
+                    }
+                ]
+            }
+        ]
+    }
+
+    response = requests.post("http://localhost:${toString port}/v1/logs", json=event)
+    assert response.status_code == 200
+    assert flag in machine.execute("journalctl -u opentelemetry-collector")[-1]
+  '';
+})