Add STOPSIGNAL instruction to dockerfiles.

This way, images creators can set the exit signal their programs use.

Signed-off-by: David Calavera <david.calavera@gmail.com>
Upstream-commit: 3781cde61ff10b1d9114ae5b4c5c1d1b2c20a1ee
Component: engine

components/engine/integration-cli/docker_cli_build_test.go

@@ -5660,3 +5660,18 @@ func (s *DockerSuite) TestBuildNullStringInAddCopyVolume(c *check.C) {
 	_, err = buildImageFromContext(name, ctx, true)
 	c.Assert(err, check.IsNil)
 }
+
+func (s *DockerSuite) TestBuildStopSignal(c *check.C) {
+	name := "test_build_stop_signal"
+	_, err := buildImage(name,
+		`FROM busybox
+		 STOPSIGNAL SIGKILL`,
+		true)
+	c.Assert(err, check.IsNil)
+	res, err := inspectFieldJSON(name, "Config.StopSignal")
+	c.Assert(err, check.IsNil)
+
+	if res != `"SIGKILL"` {
+		c.Fatalf("Signal %s, expected SIGKILL", res)
+	}
+}

components/engine/integration-cli/docker_cli_create_test.go

@@ -458,3 +458,15 @@ func (s *DockerTrustSuite) TestTrustedCreateFromBadTrustServer(c *check.C) {
 		c.Fatalf("Missing expected output on trusted push:\n%s", out)
 	}
 }
+
+func (s *DockerSuite) TestCreateStopSignal(c *check.C) {
+	name := "test_create_stop_signal"
+	dockerCmd(c, "create", "--name", name, "--stop-signal", "9", "busybox")
+
+	res, err := inspectFieldJSON(name, "Config.StopSignal")
+	c.Assert(err, check.IsNil)
+
+	if res != `"9"` {
+		c.Fatalf("Expected 9, got %s", res)
+	}
+}