Replace log with slog

README.md

@@ -149,7 +149,6 @@ For the time being, legacy configs for the Python version of Minitor should be c
 
 Future, potentially breaking changes
 
-  - [ ] Implement leveled logging (maybe glog or logrus)
   - [ ] Consider value of templating vs injecting values into Env variables
   - [ ] Async checking
   - [ ] Revisit metrics and see if they all make sense

alert.go

@@ -3,11 +3,12 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"log"
 	"os/exec"
 	"strings"
 	"text/template"
 	"time"
+
+	"git.iamthefij.com/iamthefij/slog"
 )
 
 // Alert is a config driven mechanism for sending a notice
@@ -45,9 +46,9 @@ func (alert *Alert) BuildTemplates() error {
 		"{last_success}", "{{.LastSuccess}}",
 		"{monitor_name}", "{{.MonitorName}}",
 	)
-	if LogDebug {
+
-		log.Printf("DEBUG: Building template for alert %s", alert.Name)
+	slog.Debugf("Building template for alert %s", alert.Name)
-	}
+
 	if alert.commandTemplate == nil && alert.Command.Command != nil {
 		alert.commandTemplate = []*template.Template{}
 		for i, cmdPart := range alert.Command.Command {
@@ -75,7 +76,8 @@ func (alert *Alert) BuildTemplates() error {
 
 // Send will send an alert notice by executing the command template
 func (alert Alert) Send(notice AlertNotice) (outputStr string, err error) {
-	log.Printf("INFO: Sending alert %s for %s", alert.Name, notice.MonitorName)
+	slog.Infof("Sending alert %s for %s", alert.Name, notice.MonitorName)
+
 	var cmd *exec.Cmd
 	if alert.commandTemplate != nil {
 		command := []string{}
@@ -110,9 +112,7 @@ func (alert Alert) Send(notice AlertNotice) (outputStr string, err error) {
 	var output []byte
 	output, err = cmd.CombinedOutput()
 	outputStr = string(output)
-	if LogDebug {
+	slog.Debugf("Alert output for: %s\n---\n%s\n---", alert.Name, outputStr)
-		log.Printf("DEBUG: Alert output for: %s\n---\n%s\n---", alert.Name, outputStr)
-	}
 
 	return outputStr, err
 }

config.go

@@ -3,8 +3,8 @@ package main
 import (
 	"errors"
 	"io/ioutil"
-	"log"
 
+	"git.iamthefij.com/iamthefij/slog"
 	"gopkg.in/yaml.v2"
 )
 
@@ -53,32 +53,36 @@ func (config Config) IsValid() (isValid bool) {
 	// 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")
+		slog.Errorf("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)
+			slog.Errorf("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")
+		slog.Errorf("Invalid monitor configuration: Must provide at least one monitor")
+
 		isValid = false
 	}
 	for _, monitor := range config.Monitors {
 		if !monitor.IsValid() {
-			log.Printf("ERROR: Invalid monitor configuration: %s", monitor.Name)
+			slog.Errorf("Invalid monitor configuration: %s", monitor.Name)
+
 			isValid = false
 		}
 		// Check that all Monitor alerts actually exist
 		for _, isUp := range []bool{true, false} {
 			for _, alertName := range monitor.GetAlertNames(isUp) {
 				if _, ok := config.Alerts[alertName]; !ok {
-					log.Printf(
+					slog.Errorf(
-						"ERROR: Invalid monitor configuration: %s. Unknown alert %s",
+						"Invalid monitor configuration: %s. Unknown alert %s",
 						monitor.Name, alertName,
 					)
 					isValid = false
@@ -114,9 +118,7 @@ func LoadConfig(filePath string) (config Config, err error) {
 		return
 	}
 
-	if LogDebug {
+	slog.Debugf("Config values:\n%v\n", config)
-		log.Printf("DEBUG: Config values:\n%v\n", config)
-	}
 
 	// Add log alert if not present
 	if PyCompat {

go.mod

@@ -3,6 +3,7 @@ module git.iamthefij.com/iamthefij/minitor-go
 go 1.15
 
 require (
+	git.iamthefij.com/iamthefij/slog v1.3.0
 	github.com/prometheus/client_golang v1.2.1
 	gopkg.in/yaml.v2 v2.2.4
 )

go.sum

@@ -1,3 +1,5 @@
+git.iamthefij.com/iamthefij/slog v1.3.0 h1:4Hu5PQvDrW5e3FrTS3q2iIXW0iPvhNY/9qJsqDR3K3I=
+git.iamthefij.com/iamthefij/slog v1.3.0/go.mod h1:1RUj4hcCompZkAxXCRfUX786tb3cM/Zpkn97dGfUfbg=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=

main.go

@@ -3,14 +3,12 @@ package main
 import (
 	"flag"
 	"fmt"
-	"log"
 	"time"
+
+	"git.iamthefij.com/iamthefij/slog"
 )
 
 var (
-	// LogDebug will control whether debug messsages should be logged
-	LogDebug = false
-
 	// ExportMetrics will track whether or not we want to export metrics to prometheus
 	ExportMetrics = false
 	// MetricsPort is the port to expose metrics on
@@ -38,14 +36,12 @@ func checkMonitors(config *Config) error {
 
 			// Should probably consider refactoring everything below here
 			if alertNotice != nil {
-				if LogDebug {
+				slog.Debugf("Received an alert notice from %s", alertNotice.MonitorName)
-					log.Printf("DEBUG: Recieved an alert notice from %s", alertNotice.MonitorName)
-				}
 				alertNames := monitor.GetAlertNames(alertNotice.IsUp)
 				if alertNames == nil {
 					// This should only happen for a recovery alert. AlertDown is validated not empty
-					log.Printf(
+					slog.Warningf(
-						"WARNING: Recieved alert, but no alert mechanisms exist. MonitorName=%s IsUp=%t",
+						"Received alert, but no alert mechanisms exist. MonitorName=%s IsUp=%t",
 						alertNotice.MonitorName, alertNotice.IsUp,
 					)
 				}
@@ -53,8 +49,8 @@ func checkMonitors(config *Config) error {
 					if alert, ok := config.Alerts[alertName]; ok {
 						output, err := alert.Send(*alertNotice)
 						if err != nil {
-							log.Printf(
+							slog.Errorf(
-								"ERROR: Alert '%s' failed. result=%v: output=%s",
+								"Alert '%s' failed. result=%v: output=%s",
 								alert.Name,
 								err,
 								output,
@@ -71,7 +67,8 @@ func checkMonitors(config *Config) error {
 						Metrics.CountAlert(monitor.Name, alert.Name)
 					} else {
 						// This case should never actually happen since we validate against it
-						log.Printf("ERROR: Unknown alert for monitor %s: %s", alertNotice.MonitorName, alertName)
+						slog.Errorf("Unknown alert for monitor %s: %s", alertNotice.MonitorName, alertName)
+
 						return fmt.Errorf("Unknown alert for monitor %s: %s", alertNotice.MonitorName, alertName)
 					}
 				}
@@ -83,30 +80,30 @@ func checkMonitors(config *Config) error {
 }
 
 func main() {
-	// Get debug flag
+	showVersion := flag.Bool("version", false, "Display the version of minitor and exit")
-	flag.BoolVar(&LogDebug, "debug", false, "Enables debug logs (default: false)")
+	configPath := flag.String("config", "config.yml", "Alternate configuration path (default: config.yml)")
+
+	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)")
-	var showVersion = flag.Bool("version", false, "Display the version of minitor and exit")
-	var configPath = flag.String("config", "config.yml", "Alternate configuration path (default: config.yml)")
 	flag.Parse()
 
 	// Print version if flag is provided
 	if *showVersion {
-		log.Println("Minitor version:", version)
+		fmt.Println("Minitor version:", version)
+
 		return
 	}
 
 	// Load configuration
 	config, err := LoadConfig(*configPath)
-	if err != nil {
+	slog.OnErrFatalf(err, "Error loading config: %v", err)
-		log.Fatalf("Error loading config: %v", err)
-	}
 
 	// Serve metrics exporter, if specified
 	if ExportMetrics {
-		log.Println("INFO: Exporting metrics to Prometheus")
+		slog.Infof("Exporting metrics to Prometheus")
+
 		go ServeMetrics()
 	}
 

monitor.go

@@ -1,10 +1,11 @@
 package main
 
 import (
-	"log"
 	"math"
 	"os/exec"
 	"time"
+
+	"git.iamthefij.com/iamthefij/slog"
 )
 
 // Monitor represents a particular periodic check of a command
@@ -66,17 +67,11 @@ func (monitor *Monitor) Check() (bool, *AlertNotice) {
 		alertNotice = monitor.failure()
 	}
 
-	if LogDebug {
+	slog.Debugf("Command output: %s", monitor.lastOutput)
-		log.Printf("DEBUG: Command output: %s", monitor.lastOutput)
+	slog.OnErrWarnf(err, "Command result: %v", err)
-	}
-	if err != nil {
-		if LogDebug {
-			log.Printf("DEBUG: Command result: %v", err)
-		}
-	}
 
-	log.Printf(
+	slog.Infof(
-		"INFO: %s success=%t, alert=%t",
+		"%s success=%t, alert=%t",
 		monitor.Name,
 		isSuccess,
 		alertNotice != nil,
@@ -106,15 +101,14 @@ func (monitor *Monitor) failure() (notice *AlertNotice) {
 	monitor.failureCount++
 	// If we haven't hit the minimum failures, we can exit
 	if monitor.failureCount < monitor.getAlertAfter() {
-		if LogDebug {
+		slog.Debugf(
-			log.Printf(
+			"%s failed but did not hit minimum failures. "+
-				"DEBUG: %s failed but did not hit minimum failures. "+
 				"Count: %v alert after: %v",
 			monitor.Name,
 			monitor.failureCount,
 			monitor.getAlertAfter(),
 		)
-		}
+
 		return
 	}
 

util.go

@@ -8,7 +8,7 @@ import (
 // ShellCommand takes a string and executes it as a command using `sh`
 func ShellCommand(command string) *exec.Cmd {
 	shellCommand := []string{"sh", "-c", strings.TrimSpace(command)}
-	//log.Printf("Shell command: %v", shellCommand)
+
 	return exec.Command(shellCommand[0], shellCommand[1:]...)
 }