Adds starter validation framework for semantic validation of inputs.

pkg/validate/validate.go

@@ -0,0 +1,35 @@
+package validate
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// TODO: these are rudimentary placeholder validation functions and need
+// additional work to truly match expected syntax rules.
+
+// IsValidLabel checks whether a label key/value pair has correct syntax and
+// character set
+func IsValidLabel(keyval string) (bool, error) {
+	ok, err := regexp.MatchString(`\A([a-zA-Z0-9_.-]+):([a-zA-Z0-9_.-]+)\z`, keyval)
+	if err != nil {
+		return false, err
+	}
+	if !ok {
+		return false, fmt.Errorf("invalid label format: %s", keyval)
+	}
+	return true, nil
+}
+
+// IsValidAnnotation checks whether an annotation key/value pair has correct
+// syntax and character set
+func IsValidAnnotation(keyval string) (bool, error) {
+	ok, err := regexp.MatchString(`\A([a-zA-Z0-9_.-]+):([a-zA-Z0-9_.-]+)\z`, keyval)
+	if err != nil {
+		return false, err
+	}
+	if !ok {
+		return false, fmt.Errorf("invalid annotation format: %s", keyval)
+	}
+	return true, nil
+}