simplify & optimize code

README.md

@@ -30,3 +30,15 @@ The `-c` flag allows to give a country code. Else `ch` will be used.
 ## Background
 The program uses `https://api.mullvad.net/www/relays/<SERVER_TYPE/` to get the current server list, pings the ones with the right country
 and outputs the server with the lowest ping.
+
+## Integration into a script
+I use it on my router like this (yes, I know I could have done the whole thing with jq and shell scripting, but wanted to use go for maintainability).
+```
+#!/bin/sh
+set -e
+LATEST_RELEASE=$(curl -sSL https://api.github.com/repos/bastiandoetsch/mullvad-best-server/releases/latest | jq -r '.assets[]| .browser_download_url' | grep Linux_arm64)
+curl -sSL $LATEST_RELEASE > /root/mullvad-best-server
+chmod +x /root/mullvad-best-server
+/usr/bin/wg-quick down $(wg show|grep interface | cut -d: -f2)  || echo "nothing to shut down"
+/usr/bin/wg-quick up "mullvad-$(/root/mullvad-best-server -c de)"
+```

main.go

@@ -14,8 +14,6 @@ import (
 	"time"
 )
 
-var pings = make(map[string]time.Duration)
-
 func main() {
 	zerolog.SetGlobalLevel(zerolog.InfoLevel)
 	var outputFlag = flag.String("o", "", "Output format. 'json' outputs server json")
@@ -40,16 +38,15 @@ func main() {
 }
 
 func selectBestServerIndex(servers []server, country string) int {
-	best := servers[0].Hostname
 	bestIndex := -1
+	var bestPing time.Duration
 	for i, server := range servers {
 		if server.Active && server.CountryCode == country {
 			duration, err := serverLatency(server)
 			if err == nil {
-				pings[server.Hostname] = duration
-				if bestIndex == -1 || pings[best] > pings[server.Hostname] {
-					best = server.Hostname
+				if bestIndex == -1 || bestPing > duration {
 					bestIndex = i
+					bestPing = duration
 				}
 			}
 		}