fix: add csr approval retry (#31)

actions/approve_csr_handler.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/cenkalti/backoff/v4"
 	"github.com/sirupsen/logrus"
 	"k8s.io/client-go/kubernetes"
 
@@ -19,6 +20,8 @@ func newApproveCSRHandler(log logrus.FieldLogger, clientset kubernetes.Interface
 		clientset:              clientset,
 		csrFetchInterval:       5 * time.Second,
 		initialCSRFetchTimeout: 5 * time.Minute,
+		maxRetries:             10,
+		retryAfter:             1 * time.Second,
 	}
 }
 
@@ -27,6 +30,8 @@ type approveCSRHandler struct {
 	clientset              kubernetes.Interface
 	csrFetchInterval       time.Duration
 	initialCSRFetchTimeout time.Duration
+	maxRetries             uint64
+	retryAfter             time.Duration
 }
 
 func (h *approveCSRHandler) Handle(ctx context.Context, data interface{}) error {
@@ -37,6 +42,20 @@ func (h *approveCSRHandler) Handle(ctx context.Context, data interface{}) error
 
 	log := h.log.WithField("node_name", req.NodeName)
 
+	b := backoff.WithContext(
+		backoff.WithMaxRetries(backoff.NewConstantBackOff(h.retryAfter), h.maxRetries),
+		ctx,
+	)
+	return backoff.RetryNotify(func() error {
+		return h.handle(ctx, log, req)
+	}, b, func(err error, duration time.Duration) {
+		if err != nil {
+			log.Warnf("csr approval failed, will retry: %v", err)
+		}
+	})
+}
+
+func (h *approveCSRHandler) handle(ctx context.Context, log logrus.FieldLogger, req *castai.ActionApproveCSR) error {
 	// First get original csr which is created by kubelet.
 	log.Debug("getting initial csr")
 	cert, err := h.getInitialNodeCSR(ctx, req.NodeName)

actions/approve_csr_handler_test.go

@@ -2,6 +2,8 @@ package actions
 
 import (
 	"context"
+	"fmt"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -61,6 +63,7 @@ AiAHVYZXHxxspoV0hcfn2Pdsl89fIPCOFy/K1PqSUR6QNAIgYdt51ZbQt9rgM2BD
 			}
 			return
 		})
+		var approveCalls int32
 		client.PrependReactor("update", "certificatesigningrequests", func(action ktest.Action) (handled bool, ret runtime.Object, err error) {
 			approved := csr.DeepCopy()
 			approved.Status.Conditions = []certv1.CertificateSigningRequestCondition{
@@ -72,6 +75,12 @@ AiAHVYZXHxxspoV0hcfn2Pdsl89fIPCOFy/K1PqSUR6QNAIgYdt51ZbQt9rgM2BD
 					Status:         v1.ConditionTrue,
 				},
 			}
+			// Simulate failure for some initial calls to test retry.
+			calls := atomic.LoadInt32(&approveCalls)
+			if calls < 2 {
+				atomic.AddInt32(&approveCalls, 1)
+				return true, approved, fmt.Errorf("ups")
+			}
 			return true, approved, nil
 		})
 
@@ -80,6 +89,8 @@ AiAHVYZXHxxspoV0hcfn2Pdsl89fIPCOFy/K1PqSUR6QNAIgYdt51ZbQt9rgM2BD
 			clientset:              client,
 			csrFetchInterval:       1 * time.Millisecond,
 			initialCSRFetchTimeout: 10 * time.Millisecond,
+			retryAfter:             100 * time.Millisecond,
+			maxRetries:             5,
 		}
 
 		ctx := context.Background()