added support for loading metrics from JSON file

main.go

@@ -21,6 +21,8 @@ import (
 	"net/http"
 	"sync"
 	"time"
+	"encoding/json"
+	"io/ioutil"
 
 	"github.com/namsral/flag"
 	"github.com/prometheus/client_golang/prometheus"
@@ -33,6 +35,7 @@ const serviceLoadRetryTime = 1 * time.Minute
 var (
 	flag_test = flag.Bool("test", false, "print all available metrics to stdout")
 	flag_addr = flag.String("listen-address", "127.0.0.1:9042", "The address to listen on for HTTP requests.")
+	flag_metrics_file = flag.String("metrics-file", "metrics.json", "The JSON file with the metric definitions.")
 
 	flag_gateway_url  = flag.String("gateway-url", "https://fritz.box:49443", "The URL of the FRITZ!Box")
 	flag_gateway_username = flag.String("username", "", "The user for the FRITZ!Box UPnP service")
@@ -46,140 +49,28 @@ var (
 	})
 )
 
-type Metric struct {
-	Service string
-	Action  string
-	Result  string
-	OkValue string
 
+type JSON_PromDesc struct {
+	FqName	string			`json:"fqName"`
+	Help	string			`json:"help"`
+	VarLabels	[]string	`json:"varLabels"`
+}
+
+type Metric struct {
+	// initialized loading JSON
+	Service	string		`json:"service"`
+	Action	string		`json:"action"`
+	Result	string		`json:"result"`
+	OkValue	string		`json:"okValue"`
+	PromDesc	JSON_PromDesc		`json:"promDesc"`
+	PromType	string			`json:"promType"`
+	
+	// initialized at startup
 	Desc       *prometheus.Desc
 	MetricType prometheus.ValueType
 }
 
-var metrics = []*Metric{
+var metrics []*Metric;
-	{
-		Service: "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
-		Action:  "GetTotalPacketsReceived",
-		Result:  "TotalPacketsReceived",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_packets_received",
-			"packets received on gateway WAN interface",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.CounterValue,
-	},
-	{
-		Service: "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
-		Action:  "GetTotalPacketsSent",
-		Result:  "TotalPacketsSent",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_packets_sent",
-			"packets sent on gateway WAN interface",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.CounterValue,
-	},
-	{
-		Service: "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
-		Action:  "GetAddonInfos",
-		Result:  "TotalBytesReceived",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_bytes_received",
-			"bytes received on gateway WAN interface",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.CounterValue,
-	},
-	{
-		Service: "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
-		Action:  "GetAddonInfos",
-		Result:  "TotalBytesSent",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_bytes_sent",
-			"bytes sent on gateway WAN interface",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.CounterValue,
-	},
-	{
-		Service: "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
-		Action:  "GetCommonLinkProperties",
-		Result:  "Layer1UpstreamMaxBitRate",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_layer1_upstream_max_bitrate",
-			"Layer1 upstream max bitrate",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.GaugeValue,
-	},
-	{
-		Service: "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
-		Action:  "GetCommonLinkProperties",
-		Result:  "Layer1DownstreamMaxBitRate",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_layer1_downstream_max_bitrate",
-			"Layer1 downstream max bitrate",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.GaugeValue,
-	},
-	{
-		Service: "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
-		Action:  "GetCommonLinkProperties",
-		Result:  "PhysicalLinkStatus",
-		OkValue: "Up",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_layer1_link_status",
-			"Status of physical link (Up = 1)",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.GaugeValue,
-	},
-	{
-		Service: "urn:schemas-upnp-org:service:WANIPConnection:1",
-		Action:  "GetStatusInfo",
-		Result:  "ConnectionStatus",
-		OkValue: "Connected",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_connection_status",
-			"WAN connection status (Connected = 1)",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.GaugeValue,
-	},
-	{
-		Service: "urn:schemas-upnp-org:service:WANIPConnection:1",
-		Action:  "GetStatusInfo",
-		Result:  "Uptime",
-		Desc: prometheus.NewDesc(
-			"gateway_wan_connection_uptime_seconds",
-			"WAN connection uptime",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.GaugeValue,
-	},
-	{
-		Service: "urn:dslforum-org:service:WLANConfiguration:1",
-		Action:  "GetTotalAssociations",
-		Result:  "TotalAssociations",
-		Desc: prometheus.NewDesc(
-			"gateway_wlan_current_connections",
-			"current WLAN connections",
-			[]string{"gateway"},
-			nil,
-		),
-		MetricType: prometheus.GaugeValue,
-	},
-}
 
 type FritzboxCollector struct {
 	Url      string
@@ -311,7 +202,7 @@ func test() {
 
 			res, err := a.Call()
 			if err != nil {
-				fmt.Errorf("unexpected error", err)
+				fmt.Printf("  %s unexpected error:", a.Name, err)
 				continue
 			}
 
@@ -323,12 +214,25 @@ func test() {
 	}
 }
 
+func getValueType(vt string) prometheus.ValueType {
+	switch vt {
+	case "CounterValue":
+		return prometheus.CounterValue;
+	case "GaugeValue":
+		return prometheus.GaugeValue;
+	case "UntypedValue":
+		return prometheus.UntypedValue;
+	}
+
+	return prometheus.UntypedValue;
+}
+
 func main() {
 	flag.Parse()
 
 	u, err := url.Parse(*flag_gateway_url)
 	if err != nil {
-		fmt.Errorf("invalid URL", err)
+		fmt.Println("invalid URL:", err)
 		return
 	}
 
@@ -337,6 +241,26 @@ func main() {
 		return
 	}
 
+	// read metrics 
+	jsonData, err := ioutil.ReadFile(*flag_metrics_file)
+	if err != nil {
+		fmt.Println("error reading metric file:", err)
+		return
+	}
+
+	err = json.Unmarshal(jsonData, &metrics)
+	if err != nil {
+		fmt.Println("error parsing JSON:", err)
+		return
+	}
+
+	// init metrics
+	for _, m := range metrics {
+		pd := m.PromDesc
+		m.Desc		= prometheus.NewDesc(pd.FqName, pd.Help, pd.VarLabels, nil)
+		m.MetricType	= getValueType(m.PromType)
+	}
+
 	collector := &FritzboxCollector{
 		Url:  *flag_gateway_url,
 		Gateway: u.Hostname(),

metrics.json

@@ -0,0 +1,134 @@
+[
+  {
+    "service": "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
+    "action": "GetTotalPacketsReceived",
+    "result": "TotalPacketsReceived",
+    "promDesc": {
+      "fqName": "gateway_wan_packets_received",
+      "help": "packets received on gateway WAN interface",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "CounterValue"
+  },
+  {
+    "service": "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
+    "action": "GetTotalPacketsSent",
+    "result": "TotalPacketsSent",
+    "promDesc": {
+      "fqName": "gateway_wan_packets_sent",
+      "help": "packets sent on gateway WAN interface",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "CounterValue"
+  },
+  {
+    "service": "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
+    "action": "GetAddonInfos",
+    "result": "TotalBytesReceived",
+    "promDesc": {
+      "fqName": "gateway_wan_bytes_received",
+      "help": "bytes received on gateway WAN interface",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "CounterValue"
+  },
+  {
+    "service": "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
+    "action": "GetAddonInfos",
+    "result": "TotalBytesSent",
+    "promDesc": {
+      "fqName": "gateway_wan_bytes_sent",
+      "help": "bytes sent on gateway WAN interface",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "CounterValue"
+  },
+  {
+    "service": "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
+    "action": "GetCommonLinkProperties",
+    "result": "Layer1UpstreamMaxBitRate",
+    "promDesc": {
+      "fqName": "gateway_wan_layer1_upstream_max_bitrate",
+      "help": "Layer1 upstream max bitrate",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "GaugeValue"
+  },
+  {
+    "service": "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
+    "action": "GetCommonLinkProperties",
+    "result": "Layer1DownstreamMaxBitRate",
+    "promDesc": {
+      "fqName": "gateway_wan_layer1_downstream_max_bitrate",
+      "help": "Layer1 downstream max bitrate",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "GaugeValue"
+  },
+  {
+    "service": "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1",
+    "action": "GetCommonLinkProperties",
+    "result": "PhysicalLinkStatus",
+    "okValue": "Up",
+    "promDesc": {
+      "fqName": "gateway_wan_layer1_link_status",
+      "help": "Status of physical link (Up = 1)",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "GaugeValue"
+  },
+  {
+    "service": "urn:schemas-upnp-org:service:WANIPConnection:1",
+    "action": "GetStatusInfo",
+    "result": "ConnectionStatus",
+    "okValue": "Connected",
+    "promDesc": {
+      "fqName": "gateway_wan_connection_status",
+      "help": "WAN connection status (Connected = 1)",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "GaugeValue"
+  },
+  {
+    "service": "urn:schemas-upnp-org:service:WANIPConnection:1",
+    "action": "GetStatusInfo",
+    "result": "Uptime",
+    "promDesc": {
+      "fqName": "gateway_wan_connection_uptime_seconds",
+      "help": "WAN connection uptime",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "GaugeValue"
+  },
+  {
+    "service": "urn:dslforum-org:service:WLANConfiguration:1",
+    "action": "GetTotalAssociations",
+    "result": "TotalAssociations",
+    "promDesc": {
+      "fqName": "gateway_wlan_current_connections",
+      "help": "current WLAN connections",
+      "varLabels": [
+        "gateway"
+      ]
+    },
+    "promType": "GaugeValue"
+  }
+]