Build selected targets with version injection

internal/versioncontract/version.go

@@ -0,0 +1,25 @@
+package versioncontract
+
+import "strings"
+
+// ValidStableVersion reports whether version uses the selected vMAJOR.MINOR.PATCH form.
+func ValidStableVersion(version string) bool {
+	if !strings.HasPrefix(version, "v") {
+		return false
+	}
+	components := strings.Split(version[1:], ".")
+	if len(components) != 3 {
+		return false
+	}
+	for _, component := range components {
+		if component == "" || len(component) > 1 && component[0] == '0' {
+			return false
+		}
+		for i := 0; i < len(component); i++ {
+			if component[i] < '0' || component[i] > '9' {
+				return false
+			}
+		}
+	}
+	return true
+}