feat: Implement graceful shutdown in application-controller (#19465)

* Implement graceful shutdown in argocd-application-controller

Signed-off-by: leehosu <hosu4549@gmail.com>

* Implement code to pass waitGroup to Run function

Signed-off-by: leehosu <hosu4549@gmail.com>

* Add retuen nil

Signed-off-by: leehosu <hosu4549@gmail.com>

* Add log for lean shutdown

Signed-off-by: leehosu <hosu4549@gmail.com>

* collect e2e coverage from app-controller

Signed-off-by: Michael Crenshaw <350466+crenshaw-dev@users.noreply.github.com>

* Remove select {}

Signed-off-by: leehosu <hosu4549@gmail.com>

* Add ctx.done() about application-controller

Signed-off-by: leehosu <hosu4549@gmail.com>

* simplify

Signed-off-by: Michael Crenshaw <350466+crenshaw-dev@users.noreply.github.com>

---------

Signed-off-by: leehosu <hosu4549@gmail.com>
Signed-off-by: Michael Crenshaw <350466+crenshaw-dev@users.noreply.github.com>
Co-authored-by: Michael Crenshaw <350466+crenshaw-dev@users.noreply.github.com>

.github/workflows/ci-build.yaml

@@ -364,12 +364,12 @@ jobs:
           name: test-results
           path: test-results
       - name: combine-go-coverage
-        # We generate coverage reports for all Argo CD components, but only the applicationset-controller and
-        # repo-server report contain coverage data. The other components currently don't shut down gracefully, so no
-        # coverage data is produced. Once those components are fixed, we can add references to their coverage output
-        # directories.
+        # We generate coverage reports for all Argo CD components, but only the applicationset-controller,
+        # app-controller, and repo-server report contain coverage data. The other components currently don't shut down
+        # gracefully, so no coverage data is produced. Once those components are fixed, we can add references to their
+        # coverage output directories.
         run: |
-          go tool covdata percent -i=test-results,e2e-code-coverage/applicationset-controller,e2e-code-coverage/repo-server -o test-results/full-coverage.out
+          go tool covdata percent -i=test-results,e2e-code-coverage/applicationset-controller,e2e-code-coverage/repo-server,e2e-code-coverage/app-controller -o test-results/full-coverage.out
       - name: Upload code coverage information to codecov.io
         uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673 # v4.5.0
         with:

cmd/argocd-application-controller/commands/argocd_application_controller.go

@@ -4,6 +4,9 @@ import (
 	"context"
 	"fmt"
 	"math"
+	"os"
+	"os/signal"
+	"syscall"
 	"time"
 
 	"github.com/argoproj/pkg/stats"
@@ -188,10 +191,22 @@ func NewCommand() *cobra.Command {
 				defer closeTracer()
 			}
 
+			// Graceful shutdown code
+			sigCh := make(chan os.Signal, 1)
+			signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
+			go func() {
+				s := <-sigCh
+				log.Printf("got signal %v, attempting graceful shutdown", s)
+				cancel()
+			}()
+
 			go appController.Run(ctx, statusProcessors, operationProcessors)
 
-			// Wait forever
-			select {}
+			<-ctx.Done()
+
+			log.Println("clean shutdown")
+
+			return nil
 		},
 	}