Retry helm apply on any error (#2322)

Signed-off-by: Daniel Weiße <dw@edgeless.systems>

cli/internal/helm/retryaction_test.go

@@ -0,0 +1,104 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package helm
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/edgelesssys/constellation/v2/internal/logger"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRetryApply(t *testing.T) {
+	testCases := map[string]struct {
+		applier *stubRetriableApplier
+		wantErr bool
+	}{
+		"success": {
+			applier: &stubRetriableApplier{
+				atomic: true,
+			},
+		},
+		"two errors": {
+			applier: &stubRetriableApplier{
+				applyErrs: []error{
+					assert.AnError,
+					assert.AnError,
+					nil,
+				},
+				atomic: true,
+			},
+		},
+		"retries are aborted after maximumRetryAttempts": {
+			applier: &stubRetriableApplier{
+				applyErrs: []error{
+					assert.AnError,
+					assert.AnError,
+					assert.AnError,
+					assert.AnError,
+				},
+				atomic: true,
+			},
+			wantErr: true,
+		},
+		"non atomic actions are not retried": {
+			applier: &stubRetriableApplier{
+				atomic: false,
+				applyErrs: []error{
+					assert.AnError,
+					assert.AnError,
+					nil,
+				},
+			},
+			wantErr: true,
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			assert := assert.New(t)
+
+			err := retryApply(context.Background(), tc.applier, time.Millisecond, logger.NewTest(t))
+			if tc.wantErr {
+				assert.Error(err)
+			} else {
+				assert.NoError(err)
+			}
+		})
+	}
+}
+
+type stubRetriableApplier struct {
+	atomic    bool
+	applyErrs []error
+}
+
+func (s *stubRetriableApplier) apply(context.Context) error {
+	if len(s.applyErrs) == 0 {
+		return nil
+	}
+
+	// return the first error in the list
+	// and remove it from the list
+	err := s.applyErrs[0]
+	if len(s.applyErrs) > 1 {
+		s.applyErrs = s.applyErrs[1:]
+	} else {
+		s.applyErrs = nil
+	}
+	return err
+}
+
+func (s *stubRetriableApplier) ReleaseName() string {
+	return ""
+}
+
+func (s *stubRetriableApplier) IsAtomic() bool {
+	return s.atomic
+}