fix: truncate long tags in annotation (#779)

* fix: truncate long tags in annotation * add tests --------- Co-authored-by: Grzegorz Burzyński <[email protected]>
Kong · Oct 23, 2024 · fad649a · fad649a
1 parent 0fc29d2
commit fad649a
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Showing 2 changed files with 114 additions and 6 deletions.
diff --git a/controller/konnect/ops/objects_metadata.go b/controller/konnect/ops/objects_metadata.go
@@ -46,13 +46,34 @@ type ObjectWithMetadata interface {
 // An optional set of tags can be passed to be included in the generated tags (e.g. tags from the spec).
 // It returns a slice of unique, sorted strings for deterministic output.
 func GenerateTagsForObject(obj ObjectWithMetadata, additionalTags ...string) []string {
-	var (
-		annotationTags = metadata.ExtractTags(obj)
-		k8sMetaTags    = generateKubernetesMetadataTags(obj)
-		res            = lo.Uniq(slices.Concat(annotationTags, k8sMetaTags, additionalTags))
+	const (
+		// The maximum length of a tag in Konnect.
+		maxAllowedTagLength = 128
+		// The maximum number of tags that can be attached to a Konnect entity.
+		maxAllowedTagsCount = 20
 	)
-	sort.Strings(res)
-	return res
+
+	// Truncate the tags from annotations as we do not validate their length in CEL validations rules.
+	var annotationTags []string
+	for _, tag := range metadata.ExtractTags(obj) {
+		annotationTags = append(annotationTags, truncate(tag, maxAllowedTagLength))
+	}
+
+	k8sMetaTags := generateKubernetesMetadataTags(obj)
+
+	// We concatenate the tags in this order to ensure that the k8sMetaTags and additionalTags (from spec) are never
+	// truncated below. CEL rules ensure that the total length of k8sMetaTags and additionalTags never exceeds
+	// the maximum allowed tags count. That means we will only discard tags from annotations.
+	allTags := lo.Uniq(slices.Concat(k8sMetaTags, additionalTags, annotationTags))
+
+	// If the total number of tags exceeds the maximum allowed tags counts, we limit the number of tags to the maximum
+	// allowed tags count, discarding the tags from annotations.
+	if len(allTags) > maxAllowedTagsCount {
+		allTags = allTags[:maxAllowedTagsCount]
+	}
+
+	sort.Strings(allTags)
+	return allTags
 }
 
 // generateKubernetesMetadataTags generates a list of tags from a Kubernetes object's metadata. The tags are formatted as

diff --git a/controller/konnect/ops/objects_metadata_test.go b/controller/konnect/ops/objects_metadata_test.go
@@ -261,6 +261,93 @@ func TestGenerateTagsForObject(t *testing.T) {
 				"k8s-version:v1",
 			},
 		},
+		{
+			name: "too long tags in annotations are truncated",
+			obj: func() testObjectKind {
+				obj := namespacedObject()
+				obj.ObjectMeta.Annotations = map[string]string{
+					"konghq.com/tags": "tag1,tag2,long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-tag-that-would-end-here-and-no-more-things-should-be-preserved",
+				}
+				return obj
+			}(),
+			expectedTags: []string{
+				"k8s-generation:2",
+				"k8s-group:test.objects.io",
+				"k8s-kind:TestObjectKind",
+				"k8s-name:test-object",
+				"k8s-namespace:test-namespace",
+				"k8s-uid:test-uid",
+				"k8s-version:v1",
+				"long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-tag-that-would-end-here",
+				"tag1",
+				"tag2",
+			},
+		},
+		{
+			name: "when too many tags in total, last from annotations are discarded",
+			obj: func() testObjectKind {
+				obj := namespacedObject()
+				obj.ObjectMeta.Annotations = map[string]string{
+					"konghq.com/tags": "a,b,c,d,e,f,g,h,i,j,k,l,m,iwillbediscarded",
+				}
+				return obj
+			}(),
+			expectedTags: []string{
+				"a",
+				"b",
+				"c",
+				"d",
+				"e",
+				"f",
+				"g",
+				"h",
+				"i",
+				"j",
+				"k",
+				"k8s-generation:2",
+				"k8s-group:test.objects.io",
+				"k8s-kind:TestObjectKind",
+				"k8s-name:test-object",
+				"k8s-namespace:test-namespace",
+				"k8s-uid:test-uid",
+				"k8s-version:v1",
+				"l",
+				"m",
+			},
+		},
+		{
+			name: "when too many tags in total and additional tags are passed, last from annotations are discarded",
+			obj: func() testObjectKind {
+				obj := namespacedObject()
+				obj.ObjectMeta.Annotations = map[string]string{
+					"konghq.com/tags": "a,c,e,gwillbediscarded,iwillbediscarded,kwillbediscarded,mwillbediscarded",
+				}
+				return obj
+			}(),
+			additionalTags: []string{"b", "d", "f", "h", "j", "l", "n", "o", "p", "r"},
+			expectedTags: []string{
+				"a",
+				"b",
+				"c",
+				"d",
+				"e",
+				"f",
+				"h",
+				"j",
+				"k8s-generation:2",
+				"k8s-group:test.objects.io",
+				"k8s-kind:TestObjectKind",
+				"k8s-name:test-object",
+				"k8s-namespace:test-namespace",
+				"k8s-uid:test-uid",
+				"k8s-version:v1",
+				"l",
+				"n",
+				"o",
+				"p",
+				"r",
+			},
+		},
 	}
 
 	for _, tc := range testCases {