feat(server): emit notifications as JSON to stderr when running under KopiaUI (#4322)

* feat(server): emit notifications as JSON to stderr when running under KopiaUI

* added tests

cli/command_server_notifications_test.go

@@ -2,15 +2,19 @@
 
 import (
 	"bytes"
+	"encoding/json"
 	"io"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/kopia/kopia/internal/testutil"
+	"github.com/kopia/kopia/notification/sender"
 	"github.com/kopia/kopia/tests/testenv"
 )
 
@@ -48,21 +52,32 @@ func TestServerNotifications(t *testing.T) {
 
 	var sp testutil.ServerParameters
 
-	env.SetLogOutput(true, "server")
+	jsonNotificationsReceived := make(chan string, 100)
 
-	wait, kill := env.RunAndProcessStderr(t, sp.ProcessOutput,
-		"server", "start",
+	wait, kill := env.RunAndProcessStderrAsync(t, sp.ProcessOutput, func(line string) {
+		const prefix = "NOTIFICATION: "
+
+		if strings.HasPrefix(line, prefix) {
+			t.Logf("JSON notification received: %v", line)
+
+			jsonNotificationsReceived <- line[len(prefix):]
+		}
+	}, "server", "start",
 		"--address=localhost:0",
 		"--insecure",
 		"--random-server-control-password",
+		"--kopiaui-notifications",
 		"--shutdown-grace-period", "100ms",
 	)
 
+	defer func() {
+		kill()
+		wait()
+	}()
+
 	// trigger server snapshot
 	env.RunAndExpectSuccess(t, "server", "snapshot", "--address", sp.BaseURL, "--server-control-password", sp.ServerControlPassword, dir1)
 
-	t.Logf("triggered")
-
 	select {
 	case not := <-notificationsReceived:
 		t.Logf("notification received: %v", not)
@@ -71,6 +86,18 @@ func TestServerNotifications(t *testing.T) {
 		t.Error("notification not received in time")
 	}
 
-	kill()
-	wait()
+	select {
+	case not := <-jsonNotificationsReceived:
+		// make sure we received a valid sender.Message JSON
+		dec := json.NewDecoder(strings.NewReader(not))
+		dec.DisallowUnknownFields()
+
+		var msg sender.Message
+
+		require.NoError(t, dec.Decode(&msg))
+		require.Contains(t, msg.Subject, "Kopia success")
+
+	case <-time.After(5 * time.Second):
+		t.Error("notification not received in time")
+	}
 }

cli/command_server_start.go

@@ -21,6 +21,8 @@
 
 	"github.com/kopia/kopia/internal/auth"
 	"github.com/kopia/kopia/internal/server"
+	"github.com/kopia/kopia/notification"
+	"github.com/kopia/kopia/notification/sender/jsonsender"
 	"github.com/kopia/kopia/repo"
 )
 
@@ -68,7 +70,8 @@ type commandServerStart struct {
 	debugScheduler                      bool
 	minMaintenanceInterval              time.Duration
 
-	shutdownGracePeriod time.Duration
+	shutdownGracePeriod  time.Duration
+	kopiauiNotifications bool
 
 	logServerRequests bool
 
@@ -123,6 +126,8 @@ func (c *commandServerStart) setup(svc advancedAppServices, parent commandParent
 
 	cmd.Flag("shutdown-grace-period", "Grace period for shutting down the server").Default("5s").DurationVar(&c.shutdownGracePeriod)
 
+	cmd.Flag("kopiaui-notifications", "Enable notifications to be printed to stdout for KopiaUI").BoolVar(&c.kopiauiNotifications)
+
 	c.sf.setup(svc, cmd)
 	c.co.setup(svc, cmd)
 	c.svc = svc
@@ -271,6 +276,15 @@ func (c *commandServerStart) run(ctx context.Context) (reterr error) {
 
 	onExternalConfigReloadRequest(srv.Refresh)
 
+	// enable notification to be printed to stderr where KopiaUI will pick it up
+	if c.kopiauiNotifications {
+		notification.AdditionalSenders = append(notification.AdditionalSenders,
+			jsonsender.NewJSONSender(
+				"NOTIFICATION: ",
+				c.out.stderr(),
+				notification.SeverityVerbose))
+	}
+
 	return c.startServerWithOptionalTLS(ctx, httpServer)
 }
 

cli/terminate_signal_test.go

@@ -17,7 +17,7 @@ func TestTerminate(t *testing.T) {
 
 	var sp testutil.ServerParameters
 
-	wait, interrupt := env.RunAndProcessStderrInt(t, sp.ProcessOutput, "server", "start",
+	wait, interrupt := env.RunAndProcessStderrInt(t, sp.ProcessOutput, nil, "server", "start",
 		"--address=localhost:0",
 		"--insecure")