Extra validation when converting labels to kubernetes (appsody#565)

* Extra validation when converting labels to kubernetes

* update comment

* Check for empty name

* Fix comment spelling

* Fix linter

cmd/build.go

@@ -193,23 +193,61 @@ func convertLabelsToKubeFormat(labels map[string]string) map[string]string {
 	var kubeLabels = make(map[string]string)
 
 	for key, value := range labels {
-		prefixes := strings.Split(key, ".")
-		nPrefixes := len(prefixes)
-		newKey := ""
-		for i := nPrefixes - 2; i >= 0; i-- {
-			newKey += prefixes[i]
-			if i > 0 {
-				newKey += "."
-			}
+		newKey, err := ConvertLabelToKubeFormat(key)
+		if err != nil {
+			Debug.logf("Skipping image label \"%s\" - %v", key, err)
+		} else {
+			kubeLabels[newKey] = value
 		}
-
-		newKey += "/" + prefixes[nPrefixes-1]
-		kubeLabels[newKey] = value
 	}
 
 	return kubeLabels
 }
 
+func ConvertLabelToKubeFormat(key string) (string, error) {
+	// regular expression to strip off the domain prefix
+	// this matches anything starting with an alphanumeric, followed by
+	// alphanumerics or dots, and ending with a dot
+	regex, err := regexp.Compile(`^[a-z0-9A-Z][a-z0-9A-Z.]*\.`)
+	if err != nil {
+		return "", err
+	}
+	loc := regex.FindStringIndex(key)
+	var prefix string
+	var name string
+	if loc == nil {
+		// did not start with a domain so there will be no prefix
+		prefix = ""
+		name = key
+	} else {
+		prefix = key[0:loc[1]]
+		name = key[loc[1]:]
+		// reverse the prefix domain
+		domainSections := strings.Split(prefix, ".")
+		newPrefix := ""
+		for i := len(domainSections) - 1; i >= 0; i-- {
+			if domainSections[i] != "" {
+				newPrefix += domainSections[i]
+				if i > 0 {
+					newPrefix += "."
+				}
+			}
+		}
+		prefix = newPrefix + "/"
+	}
+	if name == "" {
+		return "", errors.New("Invalid kubernetes metadata name. Must not be empty")
+	}
+	if len(prefix) > 253 {
+		return "", errors.New("Invalid kubernetes metadata prefix. Must be less than 253 characters")
+	}
+	match, err := IsValidKubernetesLabelValue(name)
+	if !match {
+		return "", errors.Errorf("Invalid kubernetes metadata name. %v", err)
+	}
+	return prefix + name, nil
+}
+
 func createLabelPairs(labels map[string]string) []string {
 	var labelsArr []string
 

cmd/utils.go

@@ -312,8 +312,8 @@ func IsValidKubernetesLabelValue(value string) (bool, error) {
 	if value == "" {
 		return true, nil
 	}
-	if len(value) > 68 {
-		return false, errors.New("The label must be 68 characters or less")
+	if len(value) > 63 {
+		return false, errors.New("The label must be 63 characters or less")
 	}
 
 	match, err := regexp.MatchString("^[a-z0-9A-Z]([a-z0-9A-Z-_.]*[a-z0-9A-Z])?$", value)

cmd/utils_test.go

@@ -226,3 +226,53 @@ func TestInvalidCmdOutput(t *testing.T) {
 	}
 
 }
+
+var convertLabelTests = []struct {
+	input          string
+	expectedOutput string
+}{
+	{"org.opencontainers.image.created", "image.opencontainers.org/created"},
+	{"dev.appsody.stack.id", "stack.appsody.dev/id"},
+	{"dev.appsody.app.name", "app.appsody.dev/name"},
+	{"dev.appsody.app-name", "appsody.dev/app-name"},
+	{"dev.app-sody.app.name", "dev/app-sody.app.name"},
+	{"d.name", "d/name"},
+	{"app.name", "app/name"},
+	{"app-name", "app-name"},
+	{"Description", "Description"},
+	{"maintainer", "maintainer"},
+	{"dev.appsody.app.a23456789012345678901234567890123456789012345678901234567890123",
+		"app.appsody.dev/a23456789012345678901234567890123456789012345678901234567890123"}, // exact length limit on name
+}
+
+func TestConvertLabelToKubeFormat(t *testing.T) {
+	for _, test := range convertLabelTests {
+		t.Run(test.input, func(t *testing.T) {
+			output, err := cmd.ConvertLabelToKubeFormat(test.input)
+			if err != nil {
+				t.Error(err)
+			} else if output != test.expectedOutput {
+				t.Errorf("Expected %s to convert to %s but got %s", test.input, test.expectedOutput, output)
+			}
+		})
+
+	}
+}
+
+var invalidConvertLabelTests = []string{
+	"inva$lid",
+	".name",
+	"dev.appsody.",
+	"dev.appsody.app.a234567890123456789012345678901234567890123456789012345678901234", // one over length limit
+}
+
+func TestInvalidConvertLabelToKubeFormat(t *testing.T) {
+	for _, test := range invalidConvertLabelTests {
+		t.Run(test, func(t *testing.T) {
+			_, err := cmd.ConvertLabelToKubeFormat(test)
+			if err == nil {
+				t.Errorf("Expected error but got none converting %s", test)
+			}
+		})
+	}
+}