Breaking: Rename minitor_check_milliseconds and minitor_monitor_up_count

To conform with Prometheus metric name best practices, these have been
renamed as follows:

  * `minitor_check_milliseconds` to `minitor_check_seconds`
  * `minitor_monitor_up_count` to `minitor_monitor_up`

.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:

.golangci.yml

@@ -1,32 +1,23 @@
 ---
 linters:
   enable:
-    - asciicheck
-    - bodyclose
-    - dogsled
-    - dupl
+    - errname
+    - errorlint
     - exhaustive
-    - gochecknoinits
-    - gocognit
-    - gocritic
-    - gocyclo
-    - goerr113
     - gofumpt
     - goimports
     - gomnd
     - goprintffuncname
-    # - gosec
-    # - ifshort
-    - interfacer
-    - maligned
     - misspell
-    - nakedret
-    - nestif
-    - nlreturn
-    - noctx
-    - unparam
+    - promlinter
+    - tagliatelle
+    - tenv
+    - testpackage
+    - thelper
+    - tparallel
+    - unconvert
+    - wrapcheck
     - wsl
-    # - errorlint
   disable:
     - gochecknoglobals
 
@@ -34,15 +25,13 @@ linters-settings:
   gosec:
     excludes:
       - G204
-#   gomnd:
-#     settings:
-#       mnd:
-#         ignored-functions: math.*
+  tagliatelle:
+    case:
+      rules:
+        yaml: snake
 
 issues:
   exclude-rules:
     - path: _test\.go
       linters:
-        - errcheck
         - gosec
-        - maligned

.pre-commit-config.yaml

@@ -1,7 +1,7 @@
 ---
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v3.4.0
+    rev: v4.4.0
     hooks:
       - id: check-added-large-files
       - id: check-yaml
@@ -10,13 +10,11 @@ repos:
       - id: trailing-whitespace
       - id: end-of-file-fixer
       - id: check-merge-conflict
-  - repo: git://github.com/dnephin/pre-commit-golang
-    rev: v0.4.0
+  - repo: https://github.com/golangci/golangci-lint
+    rev: v1.50.1
     hooks:
-      - id: go-fmt
-      - id: go-imports
       - id: golangci-lint
   - repo: https://github.com/hadolint/hadolint
-    rev: v2.4.0
+    rev: v2.12.1-beta
     hooks:
       - id: hadolint

Dockerfile

@@ -1,15 +1,11 @@
 ARG REPO=library
-FROM multiarch/qemu-user-static:4.2.0-2 as qemu-user-static
-FROM ${REPO}/alpine:3.10
-
-# Copying all qemu files because amd64 doesn't exist and cannot condional copy
-COPY --from=qemu-user-static /usr/bin/qemu-* /usr/bin/
+FROM ${REPO}/alpine:3.12
 
 RUN mkdir /app
 WORKDIR /app/
 
 # Add common checking tools
-RUN apk --no-cache add bash=~5.0 curl=~7.66 jq=~1.6
+RUN apk --no-cache add bash=~5.0 curl=~7.79 jq=~1.6
 
 # Add minitor user for running as non-root
 RUN addgroup -S minitor && adduser -S minitor -G minitor

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
@@ -16,7 +14,7 @@ ARG VERSION=dev
 ENV CGO_ENABLED=0 GOOS=linux GOARCH=${ARCH}
 RUN go build -ldflags "-X main.version=${VERSION}" -a -installsuffix nocgo -o minitor .
 
-FROM ${REPO}/alpine:3.10
+FROM ${REPO}/alpine:3.12
 RUN mkdir /app
 WORKDIR /app/
 
@@ -24,7 +22,7 @@ WORKDIR /app/
 COPY --from=builder /app/minitor .
 
 # Add common checking tools
-RUN apk --no-cache add bash=~5.0 curl=~7.66 jq=~1.6
+RUN apk --no-cache add bash=~5.0 curl=~7.79 jq=~1.6
 
 # Add minitor user for running as non-root
 RUN addgroup -S minitor && adduser -S minitor -G minitor

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 {
@@ -66,18 +68,22 @@ 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
 			Metrics.SetMonitorStatus(monitor.Name, monitor.IsUp())
-			Metrics.CountCheck(monitor.Name, success, monitor.LastCheckMilliseconds(), hasAlert)
+			Metrics.CountCheck(monitor.Name, success, monitor.LastCheckSeconds(), 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"}},
 					},

metrics.go

@@ -43,14 +43,14 @@ func NewMetrics() *MinitorMetrics {
 		),
 		checkTime: prometheus.NewGaugeVec(
 			prometheus.GaugeOpts{
-				Name: "minitor_check_milliseconds",
+				Name: "minitor_check_seconds",
 				Help: "Time in miliseconds that a check ran for",
 			},
 			[]string{"monitor", "status"},
 		),
 		monitorStatus: prometheus.NewGaugeVec(
 			prometheus.GaugeOpts{
-				Name: "minitor_monitor_up_count",
+				Name: "minitor_monitor_up",
 				Help: "Status of currently responsive monitors",
 			},
 			[]string{"monitor"},
@@ -77,7 +77,7 @@ func (metrics *MinitorMetrics) SetMonitorStatus(monitor string, isUp bool) {
 }
 
 // CountCheck counts the result of a particular Monitor check
-func (metrics *MinitorMetrics) CountCheck(monitor string, isSuccess bool, ms int64, isAlert bool) {
+func (metrics *MinitorMetrics) CountCheck(monitor string, isSuccess bool, secs float64, isAlert bool) {
 	status := "failure"
 	if isSuccess {
 		status = "success"
@@ -94,7 +94,7 @@ func (metrics *MinitorMetrics) CountCheck(monitor string, isSuccess bool, ms int
 
 	metrics.checkTime.With(
 		prometheus.Labels{"monitor": monitor, "status": status},
-	).Set(float64(ms))
+	).Set(secs)
 }
 
 // CountAlert counts an alert

monitor.go

@@ -91,9 +91,9 @@ func (monitor Monitor) IsUp() bool {
 	return monitor.alertCount == 0
 }
 
-// LastCheckMilliseconds gives number of miliseconds the last check ran for
-func (monitor Monitor) LastCheckMilliseconds() int64 {
-	return monitor.lastCheckDuration.Milliseconds()
+// LastCheckSeconds gives number of seconds the last check ran for
+func (monitor Monitor) LastCheckSeconds() float64 {
+	return monitor.lastCheckDuration.Seconds()
 }
 
 func (monitor *Monitor) success() (notice *AlertNotice) {