Add a default log alert

alert.go

@@ -112,3 +112,16 @@ func (alert Alert) Send(notice AlertNotice) (outputStr string, err error) {
 
 	return outputStr, err
 }
+
+// NewLogAlert creates an alert that does basic logging using echo
+func NewLogAlert() *Alert {
+	return &Alert{
+		Name: "log",
+		Command: CommandOrShell{
+			Command: []string{
+				"echo",
+				"{{.MonitorName}} check has failed {{.FailureCount}} times",
+			},
+		},
+	}
+}

config.go

@@ -50,6 +50,19 @@ func (cos *CommandOrShell) UnmarshalYAML(unmarshal func(interface{}) error) erro
 func (config Config) IsValid() (isValid bool) {
 	isValid = true
 
+	// Validate alerts
+	if config.Alerts == nil || len(config.Alerts) == 0 {
+		// This should never happen because there is a default alert named 'log' for now
+		log.Printf("ERROR: Invalid alert configuration: Must provide at least one alert")
+		isValid = false
+	}
+	for _, alert := range config.Alerts {
+		if !alert.IsValid() {
+			log.Printf("ERROR: Invalid alert configuration: %s", alert.Name)
+			isValid = false
+		}
+	}
+
 	// Validate monitors
 	if config.Monitors == nil || len(config.Monitors) == 0 {
 		log.Printf("ERROR: Invalid monitor configuration: Must provide at least one monitor")
@@ -74,18 +87,6 @@ func (config Config) IsValid() (isValid bool) {
 		}
 	}
 
-	// Validate alerts
-	if config.Alerts == nil || len(config.Alerts) == 0 {
-		log.Printf("ERROR: Invalid alert configuration: Must provide at least one alert")
-		isValid = false
-	}
-	for _, alert := range config.Alerts {
-		if !alert.IsValid() {
-			log.Printf("ERROR: Invalid alert configuration: %s", alert.Name)
-			isValid = false
-		}
-	}
-
 	return
 }
 
@@ -117,6 +118,16 @@ func LoadConfig(filePath string) (config Config, err error) {
 		log.Printf("DEBUG: Config values:\n%v\n", config)
 	}
 
+	// Intialize alerts list if not present
+	if config.Alerts == nil {
+		config.Alerts = map[string]*Alert{}
+	}
+
+	// Add log alert if not present
+	if _, ok := config.Alerts["log"]; !ok {
+		config.Alerts["log"] = NewLogAlert()
+	}
+
 	if !config.IsValid() {
 		err = errors.New("Invalid configuration")
 		return

config_test.go

@@ -12,6 +12,7 @@ func TestLoadConfig(t *testing.T) {
 		name       string
 	}{
 		{"./test/valid-config.yml", false, "Valid config file"},
+		{"./test/valid-default-log-alert.yml", false, "Valid config file with default log alert"},
 		{"./test/does-not-exist", true, "Invalid config path"},
 		{"./test/invalid-config-type.yml", true, "Invalid config type for key"},
 		{"./test/invalid-config-missing-alerts.yml", true, "Invalid config missing alerts"},

test/valid-default-log-alert.yml

@@ -0,0 +1,8 @@
+---
+check_interval: 1
+
+monitors:
+  - name: Command
+    command: ['echo', '$PATH']
+    alert_down: ['log']
+    alert_every: 0