example_checker.go

// Version models a specific version of a software package
type Version struct {
	SemVersion string // this could probably be structured if we care about major vs minor vs patchlevel
	Released time.Time
}

// VersionChecker describes an object that can check if a version of software is out of date with upstream
type VersionChecker interface {
	// Check returns whether currentVersion is out-of-date and returns the newest available version, or error
	Check(currentVersion Version) (outdated bool, newestVersion Version, err error)
	// Name returns the name of the software being checked
	Name() string 
}

var modules = []VersionChecker{
	// insert "modules" here
	&k8s.Checker,
	&vault.Checker,
	&redis.Checker,
}

func CheckAllVersions(currentVersions map[string]Version) {
	for _, m := range modules {
		outdated, newest, err := m.Check(currentVersions[m.Name()])
		if err != nil {
			// handle error
		}
		if outdated {
			fmt.Printf("%v is out of date! We need to upgrade to %v\n", m.Name(), newest.SemVersion)
		}
	}
}