reduce goroutine leakage in test/integration/controlplane/transformation

[aramase]

Following up on #111126 (comment) to shutdown the gRPC goroutines and reduce the number of leaked goroutines.

/sig auth

[aojea]

/cc

[aojea]

@aramase if you are too busy, just add a description on where the problem is and, if possible, suggestions on how to fix it, there is always people wanting to help with these things

[sanwishe]

Comment #108483(comment) might help.

The goroutines are coming from the fact that we're not closing the kms transformer (grpc goroutines) that is being created.
We basically create a grpc service and never close that:

kubernetes/staging/src/k8s.io/apiserver/pkg/server/options/encryptionconfig/config.go

Line 245 in 18ce801

envelopeService, err = envelopeServiceFactory(provider.KMS.Endpoint, provider.KMS.Timeout.Duration)

Fixing would probably require changing transformer interfact to implement Close method or sth like that.

[aojea]

I was thinking in something like

diff --git a/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/envelope.go b/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/envelope.go
index 30795d41a87..d6792c73479 100644
--- a/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/envelope.go
+++ b/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/envelope.go
@@ -44,6 +44,8 @@ type Service interface {
        Decrypt(data []byte) ([]byte, error)
        // Encrypt bytes to a ciphertext.
        Encrypt(data []byte) ([]byte, error)
+       // Stop the service and close the connections.
+       Stop()
 }
 
 type envelopeTransformer struct {
diff --git a/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/envelope_test.go b/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/envelope_test.go
index 4f030772eb9..adc131bea1a 100644
--- a/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/envelope_test.go
+++ b/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/envelope_test.go
@@ -71,6 +71,9 @@ func (t *testEnvelopeService) Rotate() {
        t.keyVersion = strconv.FormatInt(int64(i+1), 10)
 }
 
+func (t *testEnvelopeService) Stop() {
+}
+
 func newTestEnvelopeService() *testEnvelopeService {
        return &testEnvelopeService{
                keyVersion: "1",
diff --git a/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/grpc_service.go b/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/grpc_service.go
index c5304cd09f2..189119f8d31 100644
--- a/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/grpc_service.go
+++ b/staging/src/k8s.io/apiserver/pkg/storage/value/encrypt/envelope/grpc_service.go
@@ -152,3 +152,9 @@ func (g *gRPCService) interceptor(
 
        return invoker(ctx, method, req, reply, cc, opts...)
 }
+
+func (g *gRPCService) Stop() {
+       g.mux.Lock()
+       defer g.mux.Unlock()
+       g.connection.Close()
+}

if someone wants to give it a shot, to hook the Close() with the Storage()

[sanwishe]

@aojea Thanks for your demo, And I would like to work on this.
/assign @sanwishe

[enj]

/milestone v1.26
/triage accepted