Catch SIGTERM and shutdown gracefully.

handler.go

@@ -15,11 +15,13 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
-func handleGeminiRequest(conn net.Conn, config Config, accessLogEntries chan LogEntry, errorLog *log.Logger) {
+func handleGeminiRequest(conn net.Conn, config Config, accessLogEntries chan LogEntry, errorLog *log.Logger, wg *sync.WaitGroup) {
 	defer conn.Close()
+	defer wg.Done()
 	var tlsConn (*tls.Conn) = conn.(*tls.Conn)
 	var log LogEntry
 	log.Time = time.Now()

main.go

@@ -6,7 +6,10 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"os/signal"
 	"strconv"
+	"sync"
+	"syscall"
 )
 
 var VERSION = "0.0.0"
@@ -109,14 +112,36 @@ func main() {
 	// Restrict access to the files specified in config
 	enableSecurityRestrictions(config, errorLog)
 
-	// Infinite serve loop
-	for {
+	// Start listening for signals
+	shutdown := make(chan struct{})
+	sigterm := make(chan os.Signal, 1)
+	signal.Notify(sigterm, syscall.SIGTERM)
+	go func() {
+		<-sigterm
+		errorLog.Println("Caught SIGTERM.  Waiting for handlers to finish...")
+		close(shutdown)
+		listener.Close()
+	}()
+
+	// Infinite serve loop (SIGTERM breaks out)
+	running := true
+	var wg sync.WaitGroup
+	for running {
 		conn, err := listener.Accept()
-		if err != nil {
-			errorLog.Println("Error accepting connection: " + err.Error())
-			log.Fatal(err)
+		if err == nil {
+			wg.Add(1)
+			go handleGeminiRequest(conn, config, accessLogEntries, errorLog, &wg)
+		} else {
+			select {
+				case <-shutdown:
+					running = false
+				default:
+					errorLog.Println("Error accepting connection: " + err.Error())
+			}
 		}
-		go handleGeminiRequest(conn, config, accessLogEntries, errorLog)
 	}
+	// Wait for still-running handler Go routines to finish
+	wg.Wait()
+	errorLog.Println("Exiting.")
 
 }