System logger

cachet/config.go

@@ -5,7 +5,9 @@ import (
 	"flag"
 	"fmt"
 	"github.com/castawaylabs/cachet-monitor/system"
+	"io"
 	"io/ioutil"
+	"log"
 	"net/http"
 	"net/url"
 	"os"
@@ -13,6 +15,8 @@ import (
 
 // Static config
 var Config CachetConfig
+// Central logger
+var Logger *log.Logger
 
 // CachetConfig is the monitoring tool configuration
 type CachetConfig struct {
@@ -20,13 +24,16 @@ type CachetConfig struct {
 	APIToken   string     `json:"api_token"`
 	Monitors   []*Monitor `json:"monitors"`
 	SystemName string     `json:"system_name"`
+	LogPath    string     `json:"log_path"`
 }
 
 func init() {
 	var configPath string
 	var systemName string
+	var logPath string
 	flag.StringVar(&configPath, "c", "/etc/cachet-monitor.config.json", "Config path")
 	flag.StringVar(&systemName, "name", "", "System Name")
+	flag.StringVar(&logPath, "log", "", "Log path")
 	flag.Parse()
 
 	var data []byte
@@ -42,7 +49,6 @@ func init() {
 		}
 
 		defer response.Body.Close()
-
 		data, _ = ioutil.ReadAll(response.Body)
 
 		fmt.Println("Downloaded network configuration.")
@@ -85,4 +91,20 @@ func init() {
 		fmt.Printf("No monitors defined!\nSee sample configuration: https://github.com/CastawayLabs/cachet-monitor/blob/master/example.config.json\n")
 		os.Exit(1)
 	}
+
+	if len(logPath) > 0 {
+		Config.LogPath = logPath
+	}
+
+	var logWriter io.Writer
+	logWriter = os.Stdout
+	if len(Config.LogPath) > 0 {
+		logWriter, err = os.Create(Config.LogPath)
+		if err != nil {
+			fmt.Printf("Unable to open file '%v' for logging\n", Config.LogPath)
+			os.Exit(1)
+		}
+	}
+
+	Logger = log.New(logWriter, "", log.Llongfile | log.Ldate | log.Ltime)
 }

cachet/incident.go

@@ -2,7 +2,6 @@ package cachet
 
 import (
 	"encoding/json"
-	"fmt"
 	"strconv"
 )
 
@@ -13,7 +12,7 @@ type Incident struct {
 	Message     string     `json:"message"`
 	Status      int        `json:"status"` // 4?
 	HumanStatus string     `json:"human_status"`
-	Component   *Component `json:"component"`
+	Component   *Component `json:"-"`
 	ComponentID *int       `json:"component_id"`
 	CreatedAt   int        `json:"created_at"`
 	UpdatedAt   int        `json:"updated_at"`
@@ -33,13 +32,14 @@ type IncidentList struct {
 func GetIncidents() []Incident {
 	_, body, err := makeRequest("GET", "/incidents", nil)
 	if err != nil {
-		panic(err)
+		Logger.Printf("Cannot get incidents: %v\n", err)
+		return []Incident{}
 	}
 
 	var data IncidentList
 	err = json.Unmarshal(body, &data)
 	if err != nil {
-		fmt.Println("Cannot parse incidents.")
+		Logger.Printf("Cannot parse incidents: %v\n", err)
 	}
 
 	return data.Incidents
@@ -49,7 +49,8 @@ func GetIncidents() []Incident {
 func (incident *Incident) Send() {
 	jsonBytes, err := json.Marshal(incident)
 	if err != nil {
-		panic(err)
+		Logger.Printf("Cannot encode incident: %v\n", err)
+		return
 	}
 
 	requestType := "POST"
@@ -61,24 +62,25 @@ func (incident *Incident) Send() {
 
 	resp, body, err := makeRequest(requestType, requestURL, jsonBytes)
 	if err != nil {
-		panic(err)
+		Logger.Printf("Cannot create/update incident: %v\n", err)
+		return
 	}
 
-	fmt.Println(strconv.Itoa(resp.StatusCode) + " " + string(body))
+	Logger.Println(strconv.Itoa(resp.StatusCode) + " " + string(body))
 
 	var data IncidentData
 	err = json.Unmarshal(body, &data)
 	if err != nil {
-		fmt.Println("Cannot parse incident body.")
+		Logger.Println("Cannot parse incident body.")
 		panic(err)
 	} else {
 		incident.ID = data.Incident.ID
 	}
 
-	fmt.Println("ID:" + strconv.Itoa(incident.ID))
+	Logger.Println("ID:" + strconv.Itoa(incident.ID))
 
 	if resp.StatusCode != 200 {
-		fmt.Println("Could not create/update incident!")
+		Logger.Println("Could not create/update incident!")
 	}
 }
 
@@ -90,7 +92,7 @@ func (incident *Incident) GetSimilarIncidentID() {
 	for _, inc := range incidents {
 		if incident.Name == inc.Name && incident.Message == inc.Message && incident.Status == inc.Status && incident.HumanStatus == inc.HumanStatus {
 			incident.ID = inc.ID
-			fmt.Printf("Updated incident id to %v\n", inc.ID)
+			Logger.Printf("Updated incident id to %v\n", inc.ID)
 			break
 		}
 	}

cachet/metrics.go

@@ -2,7 +2,6 @@ package cachet
 
 import (
 	"encoding/json"
-	"fmt"
 	"strconv"
 )
 
@@ -18,7 +17,7 @@ func SendMetric(metricID int, delay int64) {
 
 	resp, _, err := makeRequest("POST", "/metrics/"+strconv.Itoa(metricID)+"/points", jsonBytes)
 	if err != nil || resp.StatusCode != 200 {
-		fmt.Printf("Could not log data point!\n%v\n", err)
+		Logger.Printf("Could not log data point!\n%v\n", err)
 		return
 	}
 }

cachet/monitor.go

@@ -1,7 +1,6 @@
 package cachet
 
 import (
-	"fmt"
 	"net/http"
 	"time"
 )
@@ -66,7 +65,7 @@ func (monitor *Monitor) AnalyseData() {
 	}
 
 	t := (float32(numDown) / float32(len(monitor.History))) * 100
-	fmt.Printf("%s %.2f%% Down at %v. Threshold: %.2f%%\n", monitor.URL, t, time.Now().UnixNano()/int64(time.Second), monitor.Threshold)
+	Logger.Printf("%s %.2f%% Down at %v. Threshold: %.2f%%\n", monitor.URL, t, time.Now().UnixNano()/int64(time.Second), monitor.Threshold)
 
 	if len(monitor.History) != 10 {
 		// not enough data
@@ -75,7 +74,7 @@ func (monitor *Monitor) AnalyseData() {
 
 	if t > monitor.Threshold && monitor.Incident == nil {
 		// is down, create an incident
-		fmt.Println("Creating incident...")
+		Logger.Println("Creating incident...")
 
 		monitor.Incident = &Incident{
 			Name:    monitor.Name + " - " + Config.SystemName,
@@ -96,7 +95,7 @@ func (monitor *Monitor) AnalyseData() {
 		monitor.Incident.Send()
 	} else if t < monitor.Threshold && monitor.Incident != nil {
 		// was down, created an incident, its now ok, make it resolved.
-		fmt.Println("Updating incident to resolved...")
+		Logger.Println("Updating incident to resolved...")
 
 		monitor.Incident.SetFixed()
 		monitor.Incident.Send()

main.go

@@ -1,24 +1,24 @@
 package main
 
 import (
-	"fmt"
 	"github.com/castawaylabs/cachet-monitor/cachet"
 	"time"
 )
 
 func main() {
 	config := cachet.Config
+	log := cachet.Logger
 
-	fmt.Printf("System: %s, API: %s\n", config.SystemName, config.APIUrl)
+	log.Printf("System: %s, API: %s\n", config.SystemName, config.APIUrl)
-	fmt.Printf("Starting %d monitors:\n", len(config.Monitors))
+	log.Printf("Starting %d monitors:\n", len(config.Monitors))
 	for _, mon := range config.Monitors {
-		fmt.Printf(" %s: GET %s & Expect HTTP %d\n", mon.Name, mon.URL, mon.ExpectedStatusCode)
+		log.Printf(" %s: GET %s & Expect HTTP %d\n", mon.Name, mon.URL, mon.ExpectedStatusCode)
 		if mon.MetricID > 0 {
-			fmt.Printf(" - Logs lag to metric id: %d\n", mon.MetricID)
+			log.Printf(" - Logs lag to metric id: %d\n", mon.MetricID)
 		}
 	}
 
-	fmt.Println()
+	log.Println()
 
 	ticker := time.NewTicker(time.Second)
 	for range ticker.C {