return nil error if 404 encountered when deleting snapshots

Signed-off-by: Steve Kriss <steve@heptio.com>

pkg/cloudprovider/aws/block_store.go

@@ -20,6 +20,7 @@ import (
 	"regexp"
 
 	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/pkg/errors"
@@ -219,7 +220,17 @@ func (b *blockStore) DeleteSnapshot(snapshotID string) error {
 
 	_, err := b.ec2.DeleteSnapshot(req)
 
-	return errors.WithStack(err)
+	// if it's a NotFound error, we don't need to return an error
+	// since the snapshot is not there.
+	// see https://docs.aws.amazon.com/AWSEC2/latest/APIReference/errors-overview.html
+	if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() == "InvalidSnapshot.NotFound" {
+		return nil
+	}
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
 }
 
 var ebsVolumeIDRegex = regexp.MustCompile("vol-.*")

pkg/cloudprovider/azure/block_store.go

@@ -19,6 +19,7 @@ package azure
 import (
 	"context"
 	"fmt"
+	"net/http"
 	"os"
 	"regexp"
 	"strings"
@@ -280,7 +281,16 @@ func (b *blockStore) DeleteSnapshot(snapshotID string) error {
 
 	err = <-errChan
 
-	return errors.WithStack(err)
+	// if it's a 404 (not found) error, we don't need to return an error
+	// since the snapshot is not there.
+	if azureErr, ok := err.(autorest.DetailedError); ok && azureErr.StatusCode == http.StatusNotFound {
+		return nil
+	}
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
 }
 
 func getComputeResourceName(subscription, resourceGroup, resource, name string) string {

pkg/cloudprovider/gcp/block_store.go

@@ -19,6 +19,7 @@ package gcp
 import (
 	"encoding/json"
 	"io/ioutil"
+	"net/http"
 	"os"
 
 	"github.com/pkg/errors"
@@ -27,6 +28,7 @@ import (
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 	"google.golang.org/api/compute/v1"
+	"google.golang.org/api/googleapi"
 
 	"k8s.io/apimachinery/pkg/runtime"
 
@@ -212,7 +214,16 @@ func getSnapshotTags(arkTags map[string]string, diskDescription string, log logr
 func (b *blockStore) DeleteSnapshot(snapshotID string) error {
 	_, err := b.gce.Snapshots.Delete(b.project, snapshotID).Do()
 
-	return errors.WithStack(err)
+	// if it's a 404 (not found) error, we don't need to return an error
+	// since the snapshot is not there.
+	if gcpErr, ok := err.(*googleapi.Error); ok && gcpErr.Code == http.StatusNotFound {
+		return nil
+	}
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
 }
 
 func (b *blockStore) GetVolumeID(pv runtime.Unstructured) (string, error) {