Merge pull request #43307 from gnufied/fix-aws-legacy-tagging

Automatic merge from submit-queue (batch tested with PRs 43313, 43257, 43271, 43307)

Fix AWS untagged instances

To revert to 1.5 behaviour we need to consider untagged
instances if no clusterID has been specified or found.

Fixes https://github.com/kubernetes/kubernetes/issues/43063 

cc @justinsb

pkg/cloudprovider/providers/aws/tags.go

@@ -19,11 +19,12 @@ package aws
 import (
 	"fmt"
 
+	"strings"
+
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/golang/glog"
 	"k8s.io/apimachinery/pkg/util/wait"
-	"strings"
 )
 
 // TagNameKubernetesClusterPrefix is the tag name we use to differentiate multiple
@@ -129,6 +130,10 @@ func (t *awsTagging) clusterTagKey() string {
 }
 
 func (t *awsTagging) hasClusterTag(tags []*ec2.Tag) bool {
+	// if the clusterID is not configured -- we consider all instances.
+	if len(t.ClusterID) == 0 {
+		return true
+	}
 	clusterTagKey := t.clusterTagKey()
 	for _, tag := range tags {
 		tagKey := aws.StringValue(tag.Key)
@@ -227,17 +232,23 @@ func (t *awsTagging) createTags(client EC2, resourceID string, lifecycle Resourc
 // Add additional filters, to match on our tags
 // This lets us run multiple k8s clusters in a single EC2 AZ
 func (t *awsTagging) addFilters(filters []*ec2.Filter) []*ec2.Filter {
+	// if there are no clusterID configured - no filtering by special tag names
+	// should be applied to revert to legacy behaviour.
+	if len(t.ClusterID) == 0 {
+		if len(filters) == 0 {
+			// We can't pass a zero-length Filters to AWS (it's an error)
+			// So if we end up with no filters; just return nil
+			return nil
+		}
+		return filters
+	}
 	// For 1.6, we always recognize the legacy tag, for the 1.5 -> 1.6 upgrade
 	// There are no "or" filters by key, so we look for both the legacy and new key, and then we have to post-filter
 	f := newEc2Filter("tag-key", TagNameKubernetesClusterLegacy, t.clusterTagKey())
+
+	// We can't pass a zero-length Filters to AWS (it's an error)
+	// So if we end up with no filters; we need to return nil
 	filters = append(filters, f)
-
-	if len(filters) == 0 {
-		// We can't pass a zero-length Filters to AWS (it's an error)
-		// So if we end up with no filters; just return nil
-		return nil
-	}
-
 	return filters
 }
 
@@ -246,6 +257,13 @@ func (t *awsTagging) buildTags(lifecycle ResourceLifecycle, additionalTags map[s
 	for k, v := range additionalTags {
 		tags[k] = v
 	}
+
+	// no clusterID is a sign of misconfigured cluster, but we can't be tagging the resources with empty
+	// strings
+	if len(t.ClusterID) == 0 {
+		return tags
+	}
+
 	// We only create legacy tags if we are using legacy tags, i.e. if we have seen a legacy tag on our instance
 	if t.usesLegacyTags {
 		tags[TagNameKubernetesClusterLegacy] = t.ClusterID