Setup logrus and set log format

This mostly matches the settings available for External DNS and sets up logrus
which is used by External DNS for where the webhook server is called.

README.md

@@ -22,8 +22,12 @@ The application arguments are as follows:
 - `tidydns-endpoint` Tidy DNS server addr
 - `zone-update-interval` The time-duration between updating the zone information
 - `log-level` Application logging level (debug, info, warn, error)
+<<<<<<< HEAD
 - `read-timeout` Read timeout in duration format (default: 5s)
 - `write-timeout` Write timeout in duration format (default: 10s)
+=======
+- `log-format` Application logging format (json or text)
+>>>>>>> fb3c360 (Setup logrus and set log format)
 
 This application is strictly meant to run in a container as a sidecar to
 External-DNS inside a Kubernetes environment. Refer to the External-DNS

cmd/webhook/logging.go

@@ -27,17 +27,24 @@ const defaultLogLevel = slog.LevelInfo
 // one of (debug, info, warn, error), an out file where the log will be printet
 // to and the addSource boolean which when true will cause slog to print the
 // func, file and sourceline of the log call.
-func loggingSetup(lvl string, out *os.File, addSource bool) *slog.Logger {
+func loggingSetup(logFormat, logLevel string, out *os.File, addSource bool) *slog.Logger {
 	programLevel := new(slog.LevelVar)
 	handlerOpts := slog.HandlerOptions{
 		Level:     programLevel,
 		AddSource: addSource,
 	}
 
-	logger := slog.New(slog.NewJSONHandler(out, &handlerOpts))
+	var h slog.Handler
+	if logFormat == "json" {
+		h = slog.NewJSONHandler(out, &handlerOpts)
+	} else {
+		h = slog.NewTextHandler(out, &handlerOpts)
+	}
+
+	logger := slog.New(h)
 	slog.SetDefault(logger)
 
-	if err := programLevel.UnmarshalText([]byte(lvl)); err != nil {
+	if err := programLevel.UnmarshalText([]byte(logLevel)); err != nil {
 		logger.Error(err.Error())
 		programLevel.Set(defaultLogLevel)
 	}

cmd/webhook/main.go

@@ -26,14 +26,16 @@ import (
 
 	"github.com/neticdk/external-dns-tidydns-webhook/cmd/webhook/tidydns"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	log "github.com/sirupsen/logrus"
 	"go.opentelemetry.io/otel/exporters/prometheus"
 	"go.opentelemetry.io/otel/sdk/metric"
 	"sigs.k8s.io/external-dns/provider/webhook/api"
 )
 
 func main() {
+	logLevel := flag.String("log-level", "info", "Set the level of logging. (default: info, options: debug, info, warning, error)")
+	logFormat := flag.String("log-format", "text", "The format in which log messages are printed (default: text, options: text, json)")
 	tidyEndpoint := flag.String("tidydns-endpoint", "", "DNS server address")
-	logLevel := flag.String("log-level", "", "logging level (debug, info, warn, err)")
 	readTimeout := flag.Duration("read-timeout", (5 * time.Second), "Read timeout in duration format (default: 5s)")
 	writeTimeout := flag.Duration("write-timeout", (10 * time.Second), "Write timeout in duration format (default: 10s)")
 
@@ -45,19 +47,16 @@ func main() {
 	tidyUsername := os.Getenv("TIDYDNS_USER")
 	tidyPassword := os.Getenv("TIDYDNS_PASS")
 
-	// If log level isn't set as a parameter, read it from the environment
-	if *logLevel == "" {
-		*logLevel = os.Getenv("EXTERNAL_DNS_LOG_LEVEL")
-	}
+	// Setup the default slog logger
+	loggingSetup(*logFormat, *logLevel, os.Stderr, true)
 
-	// If neither the application parameter or the environment sets the log
-	// level, set default
-	if *logLevel == "" {
-		*logLevel = "info"
+	// External DNS uses logrus for logging, so we need to set that up as well
+	if *logFormat == "json" {
+		log.SetFormatter(&log.JSONFormatter{})
+	} else {
+		log.SetFormatter(&log.TextFormatter{})
 	}
 
-	loggingSetup(*logLevel, os.Stderr, true)
-
 	// Print stachtraces with slog
 	defer func() {
 		if err := recover(); err != nil {