report to stdout, untested

CONFIG.md

@@ -68,12 +68,6 @@ route the whole internet through the server peer, add `0.0.0.0/0` to the list
 before adding peers. For more advanced options and theory, see
 <https://www.wireguard.com/netns/>.
 
-        "ReportFile": "/var/lib/dsnetreport.json",
-
-This is the location of the report file generated with `dsnet report`. It is
-suggested that this command is run via a cron job; the report can be safely
-consumed by a web service or DNS integration script, for instance.
-
 The report contains no sensitive information. At one site I use it together
 with [hugo](https://gohugo.io/)
 [shortcodes](https://gohugo.io/templates/shortcode-templates/) to generate a

README.md

@@ -44,7 +44,7 @@ It works on AMD64 based linux and also ARMv5.
       init        Create /etc/dsnetconfig.json containing default configuration + new keys without loading. Edit to taste.
       regenerate  Regenerate keys and config for peer
       remove      Remove a peer by hostname provided as argument + sync
-      report      Generate a JSON status report to the location configured in /etc/dsnetconfig.json.
+      report      Generate a JSON status report to stdout
       sync        Update wireguard configuration from /etc/dsnetconfig.json after validating
       up          Create the interface, run pre/post up, sync
       version     Print version
@@ -152,8 +152,8 @@ See [CONFIG.md](CONFIG.md) for an explanation of each field.
 
 # Report file overview
 
-An example report file, generated by `dsnet report` to
-`/var/lib/dsnetreport.json` by default:
+An example report file, generated by `dsnet report`. Suggested location:
+`/var/lib/dsnetreport.json`:
 
     {
         "ExternalIP": "198.51.100.2",

cmd/cli/report.go

@@ -82,17 +82,15 @@ func GenerateReport() {
 		ExitFail("Could not retrieve device '%s' (%v)", conf.InterfaceName, err)
 	}
 
-	oldReport := MustLoadDsnetReport()
 	report := GetReport(dev, conf, oldReport)
-	report.MustSave()
+	report.Print()
 }
 
 func GetReport(dev *wgtypes.Device, conf *DsnetConfig, oldReport *DsnetReport) DsnetReport {
 	peerTimeout := viper.GetDuration("peer_timeout")
 	peerExpiry := viper.GetDuration("peer_expiry")
 	wgPeerIndex := make(map[wgtypes.Key]wgtypes.Peer)
 	peerReports := make([]PeerReport, 0)
-	oldPeerReportIndex := make(map[string]PeerReport)
 	peersOnline := 0
 
 	linkDev, err := netlink.LinkByName(conf.InterfaceName)
@@ -104,12 +102,6 @@ func GetReport(dev *wgtypes.Device, conf *DsnetConfig, oldReport *DsnetReport) D
 		wgPeerIndex[peer.PublicKey] = peer
 	}
 
-	if oldReport != nil {
-		for _, report := range oldReport.Peers {
-			oldPeerReportIndex[report.Hostname] = report
-		}
-	}
-
 	for _, peer := range conf.Peers {
 		wgPeer, known := wgPeerIndex[peer.PublicKey.Key]
 
@@ -174,34 +166,9 @@ func GetReport(dev *wgtypes.Device, conf *DsnetConfig, oldReport *DsnetReport) D
 	}
 }
 
-func (report *DsnetReport) MustSave() {
-	reportFilePath := viper.GetString("report_file")
-
+func (report *DsnetReport) Print() {
 	_json, _ := json.MarshalIndent(report, "", "    ")
 	_json = append(_json, '\n')
 
-	err := ioutil.WriteFile(reportFilePath, _json, 0644)
-	check(err)
-}
-
-func MustLoadDsnetReport() *DsnetReport {
-	reportFilePath := viper.GetString("report_file_path")
-	raw, err := ioutil.ReadFile(reportFilePath)
-
-	if os.IsNotExist(err) {
-		return nil
-	} else if os.IsPermission(err) {
-		ExitFail("%s cannot be accessed. Check read permissions.", reportFilePath)
-	} else {
-		check(err)
-	}
-
-	report := DsnetReport{}
-	err = json.Unmarshal(raw, &report)
-	check(err)
-
-	err = validator.New().Struct(report)
-	check(err)
-
-	return &report
+	fmt.Print(_json)
 }

cmd/root.go

@@ -94,7 +94,7 @@ var (
 
 	reportCmd = &cobra.Command{
 		Use:   "report",
-		Short: fmt.Sprintf("Generate a JSON status report to the location configured in %s.", viper.GetString("config_file")),
+		Short: "Generate a JSON status report to stdout",
 		Run: func(cmd *cobra.Command, args []string) {
 			cli.GenerateReport()
 		},
@@ -145,7 +145,6 @@ func init() {
 	viper.SetDefault("config_file", "/etc/dsnetconfig.json")
 	viper.SetDefault("fallback_wg_bing", "wireguard-go")
 	viper.SetDefault("listen_port", 51820)
-	viper.SetDefault("report_file", "/var/lib/dsnetreport.json")
 	viper.SetDefault("interface_name", "dsnet")
 
 	// if last handshake (different from keepalive, see https://www.wireguard.com/protocol/)