Improve self-update

- don’t run update if already running same version
- add some documentation

Author: mblaschke

command/SelfUpdate.go

@@ -12,6 +12,7 @@ import (
 )
 
 type SelfUpdate struct {
+	CurrentVersion      string
 	GithubOrganization  string
 	GithubRepository    string
 	GithubAssetTemplate string
@@ -29,25 +30,35 @@ func (conf *SelfUpdate) Execute(args []string) error {
 
 	fmt.Println(fmt.Sprintf(" - latest version is %s", release.GetName()))
 
+	// check if latest version is current version
+	if release.GetName() == conf.CurrentVersion {
+		fmt.Println(" - already using the latest version")
+		return nil
+	}
+
+	// translate OS names
 	os := runtime.GOOS
 	switch (runtime.GOOS) {
 	case "darwin":
 		os = "osx"
 	}
 
+	// translate arch names
 	arch := runtime.GOARCH
 	switch (arch) {
 	case "amd64":
 		arch = "x64"
 	case "386":
 		arch = "x32"
 	}
+
+	// build asset name
 	assetName := conf.GithubAssetTemplate
 	assetName = strings.Replace(assetName, "%OS%", os, -1)
 	assetName = strings.Replace(assetName, "%ARCH%", arch, -1)
 
+	// search assets in release for the desired filename
 	fmt.Println(fmt.Sprintf(" - searching for asset \"%s\"", assetName))
-
 	for _, asset := range release.Assets {
 		if asset.GetName() == assetName {
 			downloadUrl := asset.GetBrowserDownloadURL()

main.go

@@ -70,7 +70,7 @@ func createArgparser() {
 	}
 
 	argparser.AddCommand("version", "Show version", "Show current app version", &command.Version{Name:Name, Version:Version, Author:Author})
-	argparser.AddCommand("self-update", "Self update", "Run self update of this application", &command.SelfUpdate{GithubOrganization:GithubOrganization, GithubRepository:GithubRepository, GithubAssetTemplate:GithubAssetTemplate})
+	argparser.AddCommand("self-update", "Self update", "Run self update of this application", &command.SelfUpdate{GithubOrganization:GithubOrganization, GithubRepository:GithubRepository, GithubAssetTemplate:GithubAssetTemplate, CurrentVersion:Version})
 
 	argparser.AddCommand("mysql:debug", "MySQL debug", "Show MySQL query log", &command.MysqlDebug{})
 	argparser.AddCommand("mysql:slowlog", "MySQL slow query log", "Show MySQL slow query log", &command.MysqlSlowLog{})