feat: replace go-kit logger by slog

promhippie · Sep 14, 2024 · ca21718 · ca21718
1 parent c293ca3
commit ca21718
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Showing 10 changed files with 78 additions and 127 deletions.
diff --git a/Makefile b/Makefile
@@ -16,7 +16,7 @@ endif
 
 GOBUILD ?= CGO_ENABLED=0 go build
 PACKAGES ?= $(shell go list ./...)
-SOURCES ?= $(shell find . -name "*.go" -type f)
+SOURCES ?= $(shell find . -name "*.go" -type f -not -path ./.devenv/\* -not -path ./.direnv/\*)
 GENERATE ?= $(PACKAGES)
 
 TAGS ?= netgo

diff --git a/changelog/unreleased/logging-library.md b/changelog/unreleased/logging-library.md
@@ -0,0 +1,7 @@
+Change: Switch to official logging library
+
+Since there have been a structured logger part of the Go standard library we
+thought it's time to replace the library with that. Be aware that log messages
+should change a little bit.
+
+https://github.com/promhippie/prometheus-vcd-sd/issues/292
diff --git a/pkg/action/discoverer.go b/pkg/action/discoverer.go
@@ -2,14 +2,12 @@ package action
 
 import (
 	"context"
-	"errors"
 	"fmt"
+	"log/slog"
 	"strconv"
 	"strings"
 	"time"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
 	"github.com/promhippie/prometheus-vcd-sd/pkg/client"
@@ -34,15 +32,12 @@ var (
 		"storageProfile":    providerPrefix + "storage_profile",
 		"vdc":               providerPrefix + "vdc",
 	}
-
-	// ErrClientEndpoint defines an error if the client auth fails.
-	ErrClientEndpoint = errors.New("failed to parse api url")
 )
 
 // Discoverer implements the Prometheus discoverer interface.
 type Discoverer struct {
 	configs   map[string]*client.Client
-	logger    log.Logger
+	logger    *slog.Logger
 	refresh   int
 	separator string
 	lasts     map[string]struct{}
@@ -74,8 +69,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 
 	for project, config := range d.configs {
 		if err := config.Authenticate(); err != nil {
-			level.Warn(d.logger).Log(
-				"msg", "Failed to authenticate",
+			d.logger.Error("Failed to authenticate",
 				"project", project,
 				"err", err,
 			)
@@ -91,8 +85,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 		requestDuration.WithLabelValues(project, "org").Observe(time.Since(nowOrg).Seconds())
 
 		if err != nil {
-			level.Warn(d.logger).Log(
-				"msg", "Failed to fetch org",
+			d.logger.Error("Failed to fetch org",
 				"project", project,
 				"err", err,
 			)
@@ -106,8 +99,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 		requestDuration.WithLabelValues(project, "vdc").Observe(time.Since(nowVdc).Seconds())
 
 		if err != nil {
-			level.Warn(d.logger).Log(
-				"msg", "Failed to fetch vdc",
+			d.logger.Error("Failed to fetch vdc",
 				"project", project,
 				"err", err,
 			)
@@ -132,8 +124,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 			requestDuration.WithLabelValues(project, "vapp").Observe(time.Since(nowVapp).Seconds())
 
 			if err != nil {
-				level.Warn(d.logger).Log(
-					"msg", "Failed to fetch servers",
+				d.logger.Error("Failed to fetch servers",
 					"project", project,
 					"vapp", vappName,
 					"err", err,
@@ -144,8 +135,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 			}
 
 			if vapp.VApp.Children == nil {
-				level.Debug(d.logger).Log(
-					"msg", "No servers defined",
+				d.logger.Debug("No servers defined",
 					"project", project,
 					"vapp", vappName,
 				)
@@ -155,8 +145,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 
 			servers := vapp.VApp.Children.VM
 
-			level.Debug(d.logger).Log(
-				"msg", "Requested servers",
+			d.logger.Debug("Requested servers",
 				"project", project,
 				"vapp", vappName,
 				"count", len(servers),
@@ -172,8 +161,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 				requestDuration.WithLabelValues(project, "vm").Observe(time.Since(nowMachine).Seconds())
 
 				if err != nil {
-					level.Warn(d.logger).Log(
-						"msg", "Failed to fetch vm",
+					d.logger.Error("Failed to fetch vm",
 						"project", project,
 						"vapp", vappName,
 						"server", server.Name,
@@ -190,8 +178,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 				requestDuration.WithLabelValues(project, "metadata").Observe(time.Since(nowMeta).Seconds())
 
 				if err != nil {
-					level.Warn(d.logger).Log(
-						"msg", "Failed to fetch metadata",
+					d.logger.Error("Failed to fetch metadata",
 						"project", project,
 						"vapp", vappName,
 						"server", server.Name,
@@ -244,8 +231,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 					target.Labels[model.LabelName(Labels["metadataPrefix"]+normalized)] = model.LabelValue(entry.TypedValue.Value)
 				}
 
-				level.Debug(d.logger).Log(
-					"msg", "Server added",
+				d.logger.Debug("Server added",
 					"project", project,
 					"vapp", vappName,
 					"server", vm.VM.Name,
@@ -262,8 +248,7 @@ func (d *Discoverer) getTargets(_ context.Context) ([]*targetgroup.Group, error)
 
 	for k := range d.lasts {
 		if _, ok := current[k]; !ok {
-			level.Debug(d.logger).Log(
-				"msg", "Server deleted",
+			d.logger.Debug("Server deleted",
 				"source", k,
 			)
 

diff --git a/pkg/action/metrics.go b/pkg/action/metrics.go
@@ -2,9 +2,8 @@ package action
 
 import (
 	"fmt"
+	"log/slog"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/promhippie/prometheus-vcd-sd/pkg/version"
@@ -49,11 +48,9 @@ func init() {
 }
 
 type promLogger struct {
-	logger log.Logger
+	logger *slog.Logger
 }
 
 func (pl promLogger) Println(v ...interface{}) {
-	level.Error(pl.logger).Log(
-		"msg", fmt.Sprintln(v...),
-	)
+	pl.logger.Error(fmt.Sprintln(v...))
 }
diff --git a/pkg/action/server.go b/pkg/action/server.go
@@ -4,15 +4,14 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"log/slog"
 	"net/http"
 	"net/url"
 	"os"
 	"os/signal"
 	"time"
 
 	"github.com/go-chi/chi/v5"
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/oklog/run"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/exporter-toolkit/web"
@@ -24,9 +23,8 @@ import (
 )
 
 // Server handles the server sub-command.
-func Server(cfg *config.Config, logger log.Logger) error {
-	level.Info(logger).Log(
-		"msg", "Launching Prometheus vCloud Director SD",
+func Server(cfg *config.Config, logger *slog.Logger) error {
+	logger.Info("Launching Prometheus vCloud Director SD",
 		"version", version.String,
 		"revision", version.Revision,
 		"date", version.Date,
@@ -44,8 +42,7 @@ func Server(cfg *config.Config, logger log.Logger) error {
 			username, err := config.Value(credential.Username)
 
 			if err != nil {
-				level.Error(logger).Log(
-					"msg", "Failed to read username secret",
+				logger.Error("Failed to read username secret",
 					"project", credential.Project,
 					"err", err,
 				)
@@ -56,8 +53,7 @@ func Server(cfg *config.Config, logger log.Logger) error {
 			password, err := config.Value(credential.Password)
 
 			if err != nil {
-				level.Error(logger).Log(
-					"msg", "Failed to read password secret",
+				logger.Error("Failed to read password secret",
 					"project", credential.Project,
 					"err", err,
 				)
@@ -68,12 +64,11 @@ func Server(cfg *config.Config, logger log.Logger) error {
 			parsed, err := url.ParseRequestURI(credential.URL)
 
 			if err != nil {
-				level.Error(logger).Log(
-					"msg", ErrClientEndpoint,
+				logger.Error("Failed to parse api url",
 					"project", credential.Project,
 				)
 
-				return ErrClientEndpoint
+				return fmt.Errorf("failed to parse api url")
 			}
 
 			configs[credential.Project] = client.New(
@@ -107,9 +102,8 @@ func Server(cfg *config.Config, logger log.Logger) error {
 		}
 
 		gr.Add(func() error {
-			level.Info(logger).Log(
-				"msg", "Starting metrics server",
-				"addr", cfg.Server.Addr,
+			logger.Info("Starting metrics server",
+				"address", cfg.Server.Addr,
 			)
 
 			return web.ListenAndServe(
@@ -126,16 +120,14 @@ func Server(cfg *config.Config, logger log.Logger) error {
 			defer cancel()
 
 			if err := server.Shutdown(ctx); err != nil {
-				level.Error(logger).Log(
-					"msg", "Failed to shutdown metrics gracefully",
+				logger.Error("Failed to shutdown metrics gracefully",
 					"err", err,
 				)
 
 				return
 			}
 
-			level.Info(logger).Log(
-				"msg", "Metrics shutdown gracefully",
+			logger.Info("Metrics shutdown gracefully",
 				"reason", reason,
 			)
 		})
@@ -158,7 +150,7 @@ func Server(cfg *config.Config, logger log.Logger) error {
 	return gr.Run()
 }
 
-func handler(cfg *config.Config, logger log.Logger) *chi.Mux {
+func handler(cfg *config.Config, logger *slog.Logger) *chi.Mux {
 	mux := chi.NewRouter()
 	mux.Use(middleware.Recoverer(logger))
 	mux.Use(middleware.RealIP)
@@ -198,8 +190,7 @@ func handler(cfg *config.Config, logger log.Logger) *chi.Mux {
 				content, err := os.ReadFile(cfg.Target.File)
 
 				if err != nil {
-					level.Info(logger).Log(
-						"msg", "Failed to read service discovery data",
+					logger.Error("Failed to read service discovery data",
 						"err", err,
 					)
 

diff --git a/pkg/adapter/adapter.go b/pkg/adapter/adapter.go
@@ -19,12 +19,11 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"os"
 	"path/filepath"
 	"reflect"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/prometheus/prometheus/discovery"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
 )
@@ -43,7 +42,7 @@ type Adapter struct {
 	manager *discovery.Manager
 	output  string
 	name    string
-	logger  log.Logger
+	logger  *slog.Logger
 }
 
 func mapToArray(m map[string]*customSD) []customSD {
@@ -84,7 +83,7 @@ func (a *Adapter) generateTargetGroups(allTargetGroups map[string][]*targetgroup
 		a.groups = tempGroups
 		err := a.writeOutput()
 		if err != nil {
-			level.Error(log.With(a.logger, "component", "sd-adapter")).Log("err", err)
+			a.logger.With("component", "sd-adapter").Error("", "err", err)
 		}
 	}
 
@@ -138,12 +137,12 @@ func (a *Adapter) Run() {
 }
 
 // NewAdapter creates a new instance of Adapter.
-func NewAdapter(ctx context.Context, file string, name string, d discovery.Discoverer, logger log.Logger) *Adapter {
+func NewAdapter(ctx context.Context, file string, name string, d discovery.Discoverer, logger *slog.Logger) *Adapter {
 	return &Adapter{
 		ctx:     ctx,
 		disc:    d,
 		groups:  make(map[string]*customSD),
-		manager: discovery.NewManager(ctx, logger),
+		manager: discovery.NewManager(ctx, nil),
 		output:  file,
 		name:    name,
 		logger:  logger,

diff --git a/pkg/command/health.go b/pkg/command/health.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"net/http"
 
-	"github.com/go-kit/log/level"
 	"github.com/promhippie/prometheus-vcd-sd/pkg/config"
 	"github.com/urfave/cli/v2"
 )
@@ -20,8 +19,7 @@ func Health(cfg *config.Config) *cli.Command {
 
 			if c.IsSet("vcd.config") {
 				if err := readConfig(c.String("vcd.config"), cfg); err != nil {
-					level.Error(logger).Log(
-						"msg", "Failed to read config",
+					logger.Error("Failed to read config",
 						"err", err,
 					)
 
@@ -37,8 +35,7 @@ func Health(cfg *config.Config) *cli.Command {
 			)
 
 			if err != nil {
-				level.Error(logger).Log(
-					"msg", "Failed to request health check",
+				logger.Error("Failed to request health check",
 					"err", err,
 				)
 
@@ -48,15 +45,18 @@ func Health(cfg *config.Config) *cli.Command {
 			defer resp.Body.Close()
 
 			if resp.StatusCode != 200 {
-				level.Error(logger).Log(
-					"msg", "Health check seems to be in bad state",
+				logger.Error("Health check seems to be in bad state",
 					"err", err,
 					"code", resp.StatusCode,
 				)
 
 				return err
 			}
 
+			logger.Debug("Health check seems to be fine",
+				"code", resp.StatusCode,
+			)
+
 			return nil
 		},
 	}