Function GetTagMatchingVersionOrConstraint

pkg/registry/tag.go:25–59

(tags []string, versionString string)

)

func GetTagMatchingVersionOrConstraint(tags []string, versionString string) (string, error) {
	var constraint *semver.Constraints
	if versionString == "" {
		// If the string is empty, set a wildcard constraint
		constraint, _ = semver.NewConstraint("*")
	} else {
		// when customer inputs a specific version, check whether there's an exact match first
		for _, v := range tags {
			if versionString == v {
				return v, nil
			}
		}

		// Otherwise set constraint to the string given
		var err error
		constraint, err = semver.NewConstraint(versionString)
		if err != nil {
			return "", err
		}
	}

	// Otherwise try to find the first available version matching the string,
	// in case it is a constraint
	for _, v := range tags {
		test, err := semver.NewVersion(v)
		if err != nil {
			continue
		}
		if constraint.Check(test) {
			return v, nil
		}
	}

	return "", fmt.Errorf("could not locate a version matching provided version string %s", versionString)
}