Add a shutdown handler package

We need a unified package for handling signals that shut down
Libpod and Podman. We need to be able to do different things on
receiving such a signal (`system service` wants to shut down the
service gracefully, while most other commands just want to exit)
and we need to be able to inhibit this shutdown signal while we
are waiting for some critical operations (e.g. creating a
container) to finish. This takes the first step by defining the
package that will handle this.

Signed-off-by: Matthew Heon <mheon@redhat.com>

1 files changed, 12 insertions, 5 deletions

diff --git a/pkg/api/server/server.go b/pkg/api/server/server.go
index 355a46fb7..cc5b45a65 100644
--- a/pkg/api/server/server.go
+++ b/pkg/api/server/server.go
@@ -7,7 +7,6 @@ import (
 	"net"
 	"net/http"
 	"os"
-	"os/signal"
 	goRuntime "runtime"
 	"strings"
 	"sync"
@@ -15,6 +14,7 @@ import (
 	"time"
 
 	"github.com/containers/podman/v2/libpod"
+	"github.com/containers/podman/v2/libpod/shutdown"
 	"github.com/containers/podman/v2/pkg/api/handlers"
 	"github.com/containers/podman/v2/pkg/api/server/idle"
 	"github.com/coreos/go-systemd/v22/activation"
@@ -180,8 +180,17 @@ func setupSystemd() {
 // Serve starts responding to HTTP requests.
 func (s *APIServer) Serve() error {
 	setupSystemd()
-	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+
+	// Start the shutdown signal handler.
+	if err := shutdown.Start(); err != nil {
+		return err
+	}
+	if err := shutdown.Register("server", func() error {
+		return s.Shutdown()
+	}); err != nil {
+		return err
+	}
+
 	errChan := make(chan error, 1)
 
 	go func() {
@@ -220,8 +229,6 @@ func (s *APIServer) Serve() error {
 	select {
 	case err := <-errChan:
 		return err
-	case sig := <-sigChan:
-		logrus.Infof("APIServer terminated by signal %v", sig)
 	}
 
 	return nil