idle deprovision in hub (#895)

- Feature: Hub watchdog automatically deprovisions inactive provisioned and hibernated instances
- Feature: Added `stats/activity_counters` endpoint to measure server activity
- Feature: Added configuration options for hub watchdog
  - `--hub-watchdog-provisioned-inactivity-timeout-seconds` Inactivity timeout before a provisioned instance is deprovisioned
  - `--hub-watchdog-hibernated-inactivity-timeout-seconds` Inactivity timeout before a hibernated instance is deprovisioned
  - `--hub-watchdog-inactivity-check-margin-seconds` Margin before timeout at which an activity check is issued
  - `--hub-watchdog-cycle-interval-ms` Watchdog poll interval in milliseconds
  - `--hub-watchdog-cycle-processing-budget-ms` Maximum time budget per watchdog cycle in milliseconds
  - `--hub-watchdog-instance-check-throttle-ms` Minimum delay between checks on a single instance
  - `--hub-watchdog-activity-check-connect-timeout-ms` Connect timeout for activity check requests
  - `--hub-watchdog-activity-check-request-timeout-ms` Request timeout for activity check requests

1 files changed, 72 insertions, 0 deletions

diff --git a/src/zenhttp/httpclient.cpp b/src/zenhttp/httpclient.cpp
index 4000ea8a8..96107883e 100644
--- a/src/zenhttp/httpclient.cpp
+++ b/src/zenhttp/httpclient.cpp
@@ -402,6 +402,13 @@ HttpClient::~HttpClient()
 }
 
 void
+HttpClient::SetBaseUri(std::string_view NewBaseUri)
+{
+	m_BaseUri = NewBaseUri;
+	m_Inner->SetBaseUri(NewBaseUri);
+}
+
+void
 HttpClient::SetSessionId(const Oid& SessionId)
 {
 	if (SessionId == Oid::Zero)
@@ -980,6 +987,71 @@ TEST_CASE("httpclient.password")
 		AsioServer->RequestExit();
 	}
 }
+TEST_CASE("httpclient.setbaseuri")
+{
+	struct TestHttpService : public HttpService
+	{
+		explicit TestHttpService(std::string_view Identity) : m_Identity(Identity) {}
+
+		virtual const char* BaseUri() const override { return "/test/"; }
+		virtual void		HandleRequest(HttpServerRequest& Req) override
+		{
+			Req.WriteResponse(HttpResponseCode::OK, HttpContentType::kText, m_Identity);
+		}
+
+		std::string m_Identity;
+	};
+
+	ScopedTemporaryDirectory TmpDir1;
+	ScopedTemporaryDirectory TmpDir2;
+	TestHttpService			 Service1("server-one");
+	TestHttpService			 Service2("server-two");
+
+	Ref<HttpServer> Server1 = CreateHttpAsioServer(AsioConfig{});
+	Ref<HttpServer> Server2 = CreateHttpAsioServer(AsioConfig{});
+
+	int Port1 = Server1->Initialize(0, TmpDir1.Path());
+	int Port2 = Server2->Initialize(0, TmpDir2.Path());
+	REQUIRE(Port1 != -1);
+	REQUIRE(Port2 != -1);
+
+	Server1->RegisterService(Service1);
+	Server2->RegisterService(Service2);
+
+	std::thread Thread1([&]() { Server1->Run(false); });
+	std::thread Thread2([&]() { Server2->Run(false); });
+
+	auto _ = MakeGuard([&]() {
+		if (Thread1.joinable())
+		{
+			Thread1.join();
+		}
+		if (Thread2.joinable())
+		{
+			Thread2.join();
+		}
+		Server1->Close();
+		Server2->Close();
+	});
+
+	HttpClient Client(fmt::format("127.0.0.1:{}", Port1), HttpClientSettings{}, {});
+	CHECK_EQ(Client.GetBaseUri(), fmt::format("127.0.0.1:{}", Port1));
+
+	HttpClient::Response Resp1 = Client.Get("/test/hello");
+	CHECK(Resp1.IsSuccess());
+	CHECK_EQ(Resp1.AsText(), "server-one");
+
+	Client.SetBaseUri(fmt::format("127.0.0.1:{}", Port2));
+	CHECK_EQ(Client.GetBaseUri(), fmt::format("127.0.0.1:{}", Port2));
+
+	HttpClient::Response Resp2 = Client.Get("/test/hello");
+	CHECK(Resp2.IsSuccess());
+	CHECK_EQ(Resp2.AsText(), "server-two");
+
+	Server1->RequestExit();
+	Server2->RequestExit();
+}
+
 TEST_SUITE_END();
 
 void