Make linters happy

Previously this was mistakenly returning after sending an alert. Now
all alerts will be sent unless there is an exception on one of them.

.drone.yml

@@ -4,7 +4,7 @@ name: test
 
 steps:
   - name: test
-    image: golang:1.15
+    image: golang:1.17
     environment:
       VERSION: ${DRONE_TAG:-${DRONE_COMMIT}}
     commands:
@@ -30,7 +30,7 @@ trigger:
 
 steps:
   - name: build all binaries
-    image: golang:1.15
+    image: golang:1.17
     environment:
       VERSION: ${DRONE_TAG:-${DRONE_COMMIT}}
     commands:

.pre-commit-config.yaml

@@ -10,12 +10,15 @@ repos:
       - id: trailing-whitespace
       - id: end-of-file-fixer
       - id: check-merge-conflict
+  - repo: https://github.com/golangci/golangci-lint
+    rev: v1.42.1
+    hooks:
+      - id: golangci-lint
   - repo: git://github.com/dnephin/pre-commit-golang
     rev: v0.4.0
     hooks:
       - id: go-fmt
       - id: go-imports
-      - id: golangci-lint
   - repo: https://github.com/hadolint/hadolint
     rev: v2.4.0
     hooks:

Dockerfile.multi-stage

@@ -1,7 +1,5 @@
 ARG REPO=library
-FROM golang:1.12-alpine AS builder
-
-RUN apk add --no-cache git=~2
+FROM golang:1.17 AS builder
 
 RUN mkdir /app
 WORKDIR /app

main.go

@@ -36,6 +36,8 @@ func sendAlerts(config *Config, monitor *Monitor, alertNotice *AlertNotice) erro
 			"Received alert, but no alert mechanisms exist. MonitorName=%s IsUp=%t",
 			alertNotice.MonitorName, alertNotice.IsUp,
 		)
+
+		return nil
 	}
 
 	for _, alertName := range alertNames {
@@ -66,10 +68,10 @@ func sendAlerts(config *Config, monitor *Monitor, alertNotice *AlertNotice) erro
 }
 
 func checkMonitors(config *Config) error {
+	// TODO: Run this in goroutines and capture exceptions
 	for _, monitor := range config.Monitors {
 		if monitor.ShouldCheck() {
 			success, alertNotice := monitor.Check()
-
 			hasAlert := alertNotice != nil
 
 			// Track status metrics
@@ -77,7 +79,11 @@ func checkMonitors(config *Config) error {
 			Metrics.CountCheck(monitor.Name, success, monitor.LastCheckMilliseconds(), hasAlert)
 
 			if alertNotice != nil {
-				return sendAlerts(config, monitor, alertNotice)
+				err := sendAlerts(config, monitor, alertNotice)
+				// If there was an error in sending an alert, exit early and bubble it up
+				if err != nil {
+					return err
+				}
 			}
 		}
 	}
@@ -92,7 +98,7 @@ func main() {
 	flag.BoolVar(&slog.DebugLevel, "debug", false, "Enables debug logs (default: false)")
 	flag.BoolVar(&ExportMetrics, "metrics", false, "Enables prometheus metrics exporting (default: false)")
 	flag.BoolVar(&PyCompat, "py-compat", false, "Enables support for legacy Python Minitor config. Will eventually be removed. (default: false)")
-	flag.IntVar(&MetricsPort, "metrics-port", 8080, "The port that Prometheus metrics should be exported on, if enabled. (default: 8080)")
+	flag.IntVar(&MetricsPort, "metrics-port", MetricsPort, "The port that Prometheus metrics should be exported on, if enabled. (default: 8080)")
 	flag.Parse()
 
 	// Print version if flag is provided
@@ -116,9 +122,7 @@ func main() {
 	// Start main loop
 	for {
 		err = checkMonitors(&config)
-		if err != nil {
-			panic(err)
-		}
+		slog.OnErrPanicf(err, "Error checking monitors")
 
 		time.Sleep(config.CheckInterval.Value())
 	}

main_test.go

@@ -16,7 +16,7 @@ func TestCheckMonitors(t *testing.T) {
 		{
 			config: Config{
 				Monitors: []*Monitor{
-					&Monitor{
+					{
 						Name:    "Success",
 						Command: CommandOrShell{Command: []string{"true"}},
 					},
@@ -28,7 +28,7 @@ func TestCheckMonitors(t *testing.T) {
 		{
 			config: Config{
 				Monitors: []*Monitor{
-					&Monitor{
+					{
 						Name:       "Failure",
 						Command:    CommandOrShell{Command: []string{"false"}},
 						AlertAfter: 1,
@@ -41,7 +41,7 @@ func TestCheckMonitors(t *testing.T) {
 		{
 			config: Config{
 				Monitors: []*Monitor{
-					&Monitor{
+					{
 						Name:       "Success",
 						Command:    CommandOrShell{Command: []string{"ls"}},
 						alertCount: 1,
@@ -54,7 +54,7 @@ func TestCheckMonitors(t *testing.T) {
 		{
 			config: Config{
 				Monitors: []*Monitor{
-					&Monitor{
+					{
 						Name:       "Failure",
 						Command:    CommandOrShell{Command: []string{"false"}},
 						AlertDown:  []string{"unknown"},
@@ -68,7 +68,7 @@ func TestCheckMonitors(t *testing.T) {
 		{
 			config: Config{
 				Monitors: []*Monitor{
-					&Monitor{
+					{
 						Name:       "Success",
 						Command:    CommandOrShell{Command: []string{"true"}},
 						AlertUp:    []string{"unknown"},
@@ -82,7 +82,7 @@ func TestCheckMonitors(t *testing.T) {
 		{
 			config: Config{
 				Monitors: []*Monitor{
-					&Monitor{
+					{
 						Name:       "Failure",
 						Command:    CommandOrShell{Command: []string{"false"}},
 						AlertDown:  []string{"good"},
@@ -90,7 +90,7 @@ func TestCheckMonitors(t *testing.T) {
 					},
 				},
 				Alerts: map[string]*Alert{
-					"good": &Alert{
+					"good": {
 						Command: CommandOrShell{Command: []string{"true"}},
 					},
 				},
@@ -101,7 +101,7 @@ func TestCheckMonitors(t *testing.T) {
 		{
 			config: Config{
 				Monitors: []*Monitor{
-					&Monitor{
+					{
 						Name:       "Failure",
 						Command:    CommandOrShell{Command: []string{"false"}},
 						AlertDown:  []string{"bad"},
@@ -109,7 +109,7 @@ func TestCheckMonitors(t *testing.T) {
 					},
 				},
 				Alerts: map[string]*Alert{
-					"bad": &Alert{
+					"bad": {
 						Name:    "bad",
 						Command: CommandOrShell{Command: []string{"false"}},
 					},