Switch to log/slog package

exporter/collector.go

@@ -3,7 +3,7 @@ package exporter
 import (
 	"context"
 	"fmt"
-	"log"
+	"log/slog"
 	"strconv"
 
 	"github.com/digineo/triax-eoc-exporter/triax"
@@ -72,7 +72,7 @@ func (t *triaxCollector) Collect(ch chan<- prometheus.Metric) {
 	ch <- prometheus.MustNewConstMetric(ctrlUp, prometheus.GaugeValue, boolToFloat(err == nil))
 
 	if err != nil {
-		log.Println("fetching failed:", err)
+		slog.Error("fetching failed", "error", err)
 	}
 }
 

exporter/exporter.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"log/slog"
 	"net"
 	"net/http"
 	"text/template"
@@ -30,7 +31,7 @@ func (cfg *Config) Start(listenAddress, version string) {
 	router.GET("/controllers/:target/api/*path", cfg.targetMiddleware(cfg.apiHandler))
 	router.PUT("/controllers/:target/nodes/:mac", cfg.targetMiddleware(cfg.updateNodeHandler))
 
-	log.Printf("Starting exporter on http://%s/", listenAddress)
+	slog.Info("Starting exporter", "address", fmt.Sprintf("http://%s/", listenAddress))
 	log.Fatal(http.ListenAndServe(listenAddress, router))
 }
 

main.go

@@ -3,10 +3,11 @@ package main
 import (
 	"fmt"
 	"log"
+	"log/slog"
+	"os"
 	"runtime/debug"
 
 	"github.com/digineo/triax-eoc-exporter/exporter"
-	"github.com/digineo/triax-eoc-exporter/triax"
 
 	kingpin "github.com/alecthomas/kingpin/v2"
 )
@@ -36,10 +37,10 @@ func main() {
 		"Path to config.toml that contains all the targets.",
 	).Default(DefaultConfigPath).String()
 
-	verbose := kingpin.Flag(
-		"verbose",
-		"Increase verbosity",
-	).Bool()
+	logLevel := kingpin.Flag(
+		"log.level",
+		"Set log level (debug/info/warn/error)",
+	).Default("info").String()
 
 	kingpin.HelpFlag.Short('h')
 	kingpin.Parse()
@@ -49,10 +50,25 @@ func main() {
 		log.Fatal(err.Error())
 	}
 
-	triax.Verbose = *verbose
+	setLogger(*logLevel)
 	cfg.Start(*listenAddress, version)
 }
 
+func setLogger(logLevel string) {
+
+	levelVar := slog.LevelVar{}
+
+	if err := levelVar.UnmarshalText([]byte(logLevel)); err != nil {
+		log.Panicf("Invalid log level %s: %v", logLevel, err)
+	}
+
+	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
+		Level: levelVar.Level(),
+	}))
+
+	slog.SetDefault(logger)
+}
+
 func printVersion() {
 	info, ok := debug.ReadBuildInfo()
 	if !ok {

triax/client.go

@@ -8,8 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
-	"log"
+	"log/slog"
 	"net/http"
 	"net/http/cookiejar"
 	"net/url"
@@ -24,9 +23,6 @@ type Client struct {
 }
 
 var (
-	// Verbose increases verbosity.
-	Verbose bool
-
 	HTTPClient = http.Client{
 		Timeout: time.Second * 30,
 	}
@@ -123,9 +119,7 @@ retry:
 func (c *Client) apiRequestRaw(ctx context.Context, method, path string, request, response interface{}) error {
 	url := fmt.Sprintf("%s://%s/api/%s", c.endpoint.Scheme, c.endpoint.Host, strings.TrimPrefix(path, "/"))
 
-	if Verbose {
-		log.Printf("%s %s", method, url)
-	}
+	slog.Debug("Fetching", "method", method, "url", url)
 
 	var body io.Reader
 	if request != nil {
@@ -153,7 +147,7 @@ func (c *Client) apiRequestRaw(ctx context.Context, method, path string, request
 	defer res.Body.Close()
 
 	if res.StatusCode != http.StatusOK {
-		data, _ := ioutil.ReadAll(res.Body)
+		data, _ := io.ReadAll(res.Body)
 
 		return &ErrUnexpectedStatus{
 			Method: method,
@@ -163,16 +157,16 @@ func (c *Client) apiRequestRaw(ctx context.Context, method, path string, request
 		}
 	}
 
-	jsonData, err := ioutil.ReadAll(res.Body)
+	jsonData, err := io.ReadAll(res.Body)
 	if err != nil {
 		return err
 	}
 
 	if response != nil {
 		err = json.Unmarshal(jsonData, &response)
-		if Verbose || err != nil {
-			log.Println(string(jsonData))
-		}
+
+		slog.Debug("Response", "body", string(jsonData))
+
 		if err != nil {
 			return fmt.Errorf("decoding response failed: %w", err)
 		}