add `pkg/systemd/notifyproxy`

Add a new package for proxying notify sockets and waiting for the
READY=1 message to appear.  May subject to further changes in
future commits.

Tests make sure that it behaves properly.

Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/pkg/systemd/notifyproxy/notifyproxy_test.go b/pkg/systemd/notifyproxy/notifyproxy_test.go
new file mode 100644
index 000000000..edad95659
--- /dev/null
+++ b/pkg/systemd/notifyproxy/notifyproxy_test.go
@@ -0,0 +1,58 @@
+package notifyproxy
+
+import (
+	"testing"
+	"time"
+
+	"github.com/coreos/go-systemd/v22/daemon"
+	"github.com/stretchr/testify/require"
+)
+
+// Helper function to send the specified message over the socket of the proxy.
+func sendMessage(t *testing.T, proxy *NotifyProxy, message string) {
+	err := SendMessage(proxy.SocketPath(), message)
+	require.NoError(t, err)
+}
+
+func TestNotifyProxy(t *testing.T) {
+	proxy, err := New("")
+	require.NoError(t, err)
+	require.FileExists(t, proxy.SocketPath())
+	require.NoError(t, proxy.close())
+	require.NoFileExists(t, proxy.SocketPath())
+}
+
+func TestWaitAndClose(t *testing.T) {
+	proxy, err := New("")
+	require.NoError(t, err)
+	require.FileExists(t, proxy.SocketPath())
+
+	ch := make(chan error)
+
+	go func() {
+		ch <- proxy.WaitAndClose()
+	}()
+
+	sendMessage(t, proxy, "foo\n")
+	time.Sleep(250 * time.Millisecond)
+	select {
+	case err := <-ch:
+		t.Fatalf("Should stil be waiting but received %v", err)
+	default:
+	}
+
+	sendMessage(t, proxy, daemon.SdNotifyReady+"\nsomething else")
+	done := func() bool {
+		for i := 0; i < 10; i++ {
+			select {
+			case err := <-ch:
+				require.NoError(t, err, "Waiting should succeed")
+				return true
+			default:
+				time.Sleep(time.Duration(i*250) * time.Millisecond)
+			}
+		}
+		return false
+	}()
+	require.True(t, done, "READY MESSAGE SHOULD HAVE ARRIVED")
+}