Add custom type to parse out seconds as int and durations as strings

config.go

@@ -13,7 +13,7 @@ var errInvalidConfig = errors.New("Invalid configuration")
 
 // Config type is contains all provided user configuration
 type Config struct {
-	CheckInterval time.Duration `yaml:"check_interval"`
+	CheckInterval SecondsOrDuration `yaml:"check_interval"`
 	Monitors      []*Monitor
 	Alerts        map[string]*Alert
 }
@@ -52,6 +52,34 @@ func (cos *CommandOrShell) UnmarshalYAML(unmarshal func(interface{}) error) erro
 	return nil
 }
 
+// SecondsOrDuration wraps a duration value for parsing a duration or seconds from YAML
+// NOTE: This should be removed in favor of only parsing durations once compatibility is broken
+type SecondsOrDuration struct {
+	value time.Duration
+}
+
+// Value returns a duration value
+func (sod SecondsOrDuration) Value() time.Duration {
+	return sod.value
+}
+
+// UnmarshalYAML allows unmarshalling a duration value or seconds if an int was provided
+func (sod *SecondsOrDuration) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var seconds int64
+	err := unmarshal(&seconds)
+
+	if err == nil {
+		sod.value = time.Second * time.Duration(seconds)
+
+		return nil
+	}
+
+	// Error indicates that we don't have an int
+	err = unmarshal(&sod.value)
+
+	return err
+}
+
 // IsValid checks config validity and returns true if valid
 func (config Config) IsValid() (isValid bool) {
 	isValid = true

config_test.go

@@ -52,15 +52,15 @@ func TestIntervalParsing(t *testing.T) {
 	oneMinute := time.Minute
 
 	// validate top level interval seconds represented as an int
-	if config.CheckInterval != oneSecond {
+	if config.CheckInterval.Value() != oneSecond {
 		t.Errorf("Incorrectly parsed int seconds. expected=%v actual=%v", oneSecond, config.CheckInterval)
 	}
 
-	if config.Monitors[0].CheckInterval != tenSeconds {
+	if config.Monitors[0].CheckInterval.Value() != tenSeconds {
 		t.Errorf("Incorrectly parsed seconds duration. expected=%v actual=%v", oneSecond, config.CheckInterval)
 	}
 
-	if config.Monitors[1].CheckInterval != oneMinute {
+	if config.Monitors[1].CheckInterval.Value() != oneMinute {
 		t.Errorf("Incorrectly parsed seconds duration. expected=%v actual=%v", oneSecond, config.CheckInterval)
 	}
 

main.go

@@ -120,6 +120,6 @@ func main() {
 			panic(err)
 		}
 
-		time.Sleep(config.CheckInterval)
+		time.Sleep(config.CheckInterval.Value())
 	}
 }

monitor.go

@@ -11,9 +11,9 @@ import (
 // Monitor represents a particular periodic check of a command
 type Monitor struct { //nolint:maligned
 	// Config values
-	AlertAfter    int16         `yaml:"alert_after"`
+	AlertAfter    int16             `yaml:"alert_after"`
-	AlertEvery    int16         `yaml:"alert_every"`
+	AlertEvery    int16             `yaml:"alert_every"`
-	CheckInterval time.Duration `yaml:"check_interval"`
+	CheckInterval SecondsOrDuration `yaml:"check_interval"`
 	Name          string
 	AlertDown     []string `yaml:"alert_down"`
 	AlertUp       []string `yaml:"alert_up"`
@@ -45,7 +45,7 @@ func (monitor Monitor) ShouldCheck() bool {
 
 	sinceLastCheck := time.Since(monitor.lastCheck)
 
-	return sinceLastCheck >= monitor.CheckInterval
+	return sinceLastCheck >= monitor.CheckInterval.Value()
 }
 
 // Check will run the command configured by the Monitor and return a status

monitor_test.go

@@ -45,9 +45,9 @@ func TestMonitorShouldCheck(t *testing.T) {
 		name     string
 	}{
 		{Monitor{}, true, "Empty"},
-		{Monitor{lastCheck: timeNow, CheckInterval: time.Second * 15}, false, "Just checked"},
+		{Monitor{lastCheck: timeNow, CheckInterval: SecondsOrDuration{time.Second * 15}}, false, "Just checked"},
-		{Monitor{lastCheck: timeTenSecAgo, CheckInterval: time.Second * 15}, false, "-10s"},
+		{Monitor{lastCheck: timeTenSecAgo, CheckInterval: SecondsOrDuration{time.Second * 15}}, false, "-10s"},
-		{Monitor{lastCheck: timeTwentySecAgo, CheckInterval: time.Second * 15}, true, "-20s"},
+		{Monitor{lastCheck: timeTwentySecAgo, CheckInterval: SecondsOrDuration{time.Second * 15}}, true, "-20s"},
 	}
 
 	for _, c := range cases {