Gracefully handle SIGTERM

Apache sends SIGTERM to the logger process to it shutdown. Honestly I
thought it would just close stdin and I should have checked.

3 files changed, 50 insertions, 2 deletions

diff --git a/src/ingestor.cpp b/src/ingestor.cpp
index def3ce1..e2018ad 100644
--- a/src/ingestor.cpp
+++ b/src/ingestor.cpp
@@ -3,6 +3,7 @@
 #include "uaLookup.hpp"
 #include "util.hpp"
 #include <connection.h>
+#include <csignal>
 #include <dbTypes.h>
 #include <fstream>
 #include <modifycommand.h>
@@ -64,8 +65,11 @@ namespace WebStat {
 				return std::make_tuple(std::get<N>(ENTITY_TYPE_MAP)(std::get<N>(values))...);
 			}(std::make_index_sequence<VALUE_COUNT>());
 		}
+
 	}
 
+	Ingestor * Ingestor::currentIngestor = nullptr;
+
 	Ingestor::Ingestor(const utsname & host, IngestorSettings settings) :
 		Ingestor {host,
 				std::make_shared<DB::ConnectionPool>(
@@ -84,6 +88,31 @@ namespace WebStat {
 		bindMany(ins, 0, hostnameId, host.nodename, host.sysname, host.release, host.version, host.machine,
 				host.domainname);
 		ins->execute();
+
+		assert(!currentIngestor);
+		currentIngestor = this;
+		signal(SIGTERM, &sigtermHandler);
+	}
+
+	Ingestor::~Ingestor()
+	{
+		assert(currentIngestor);
+		signal(SIGTERM, SIG_DFL);
+		currentIngestor = nullptr;
+	}
+
+	void
+	Ingestor::sigtermHandler(int sigNo)
+	{
+		assert(currentIngestor);
+		currentIngestor->terminate(sigNo);
+	}
+
+	void
+	Ingestor::terminate(int)
+	{
+		terminated = true;
+		curl_multi_wakeup(curl.get());
 	}
 
 	Ingestor::ScanResult
@@ -138,7 +167,7 @@ namespace WebStat {
 
 		const auto curlTimeOut = static_cast<int>(
 				std::chrono::duration_cast<std::chrono::milliseconds>(settings.checkJobsAfter).count());
-		while (curl_multi_poll(curl.get(), &logIn, 1, curlTimeOut, nullptr) == CURLM_OK) {
+		while (!terminated && curl_multi_poll(curl.get(), &logIn, 1, curlTimeOut, nullptr) == CURLM_OK) {
 			if (logIn.revents) {
 				if (auto line = scn::scan<std::string>(input, "{:[^\n]}\n")) {
 					linesRead++;
diff --git a/src/ingestor.hpp b/src/ingestor.hpp
index 0bf2297..2ae2936 100644
--- a/src/ingestor.hpp
+++ b/src/ingestor.hpp
@@ -39,7 +39,7 @@ namespace WebStat {
 		Ingestor(const utsname &, IngestorSettings);
 		Ingestor(const utsname &, DB::ConnectionPoolPtr, IngestorSettings);
 
-		virtual ~Ingestor() = default;
+		virtual ~Ingestor();
 		SPECIAL_MEMBERS_DELETE(Ingestor);
 
 		using ScanResult = decltype(scn::scan<std::string_view, std::string_view, uint64_t, std::string_view,
@@ -63,6 +63,7 @@ namespace WebStat {
 		IngestorSettings settings;
 
 	protected:
+		static Ingestor * currentIngestor;
 		DB::ConnectionPoolPtr dbpool;
 
 		size_t linesRead = 0;
@@ -71,6 +72,8 @@ namespace WebStat {
 		size_t linesParked = 0;
 		mutable std::flat_set<Crc32Value> existingEntities;
 
+		bool terminated = false;
+
 		struct Job {
 			using LastRunTime = std::chrono::system_clock::time_point;
 			using Impl = unsigned int (Ingestor::*)();
@@ -98,6 +101,9 @@ namespace WebStat {
 		void jobIngestParkedLine(const std::filesystem::directory_iterator &);
 		void jobIngestParkedLine(const std::filesystem::path &, uintmax_t size);
 
+		static void sigtermHandler(int);
+		void terminate(int);
+
 		using CurlOperations = std::map<CURL *, std::unique_ptr<CurlOperation>>;
 		uint32_t hostnameId;
 		CurlMultiPtr curl;
diff --git a/test/test-ingest.cpp b/test/test-ingest.cpp
index 41b3690..be3be56 100644
--- a/test/test-ingest.cpp
+++ b/test/test-ingest.cpp
@@ -249,6 +249,19 @@ BOOST_AUTO_TEST_CASE(StoreLog, *boost::unit_test::depends_on("I/StoreLogLine"))
 	BOOST_CHECK_EQUAL(linesDiscarded, 0);
 }
 
+BOOST_AUTO_TEST_CASE(TerminateHandler, *boost::unit_test::timeout(5))
+{
+	WebStat::FilePtr input {fopen("/dev/null", "r")};
+	BOOST_REQUIRE(input);
+	BOOST_REQUIRE(!terminated);
+	raise(SIGTERM);
+	BOOST_REQUIRE(terminated);
+	ingestLog(input.get());
+	BOOST_CHECK_EQUAL(linesRead, 0);
+	BOOST_CHECK_EQUAL(linesParsed, 0);
+	BOOST_CHECK_EQUAL(linesDiscarded, 0);
+}
+
 BOOST_AUTO_TEST_CASE(ParkLogLine)
 {
 	parkLogLine(LOGLINE1);