From 394efa66a6059cf732e68c83bfc3fe8638b77b65 Mon Sep 17 00:00:00 2001
From: ludo <controlplane@spiarh.fr>
Date: Mon, 8 Jan 2024 15:08:37 +0100
Subject: [PATCH] feat: add flag to change log level

Signed-off-by: ludo <controlplane@spiarh.fr>
---
 cmd/container/main.go       |  4 ----
 cmd/simulator/main.go       |  3 ---
 docs/cli.md                 |  8 ++++++++
 internal/cli/simulator.go   | 25 +++++++++++++++++++++++++
 internal/logging/factory.go | 22 ++++++++++++++++++++--
 5 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/cmd/container/main.go b/cmd/container/main.go
index b506ed2a..3571587f 100644
--- a/cmd/container/main.go
+++ b/cmd/container/main.go
@@ -10,7 +10,6 @@ import (
 	"github.com/controlplaneio/simulator/v2/core/tools"
 	"github.com/controlplaneio/simulator/v2/internal/cli"
 	"github.com/controlplaneio/simulator/v2/internal/config"
-	"github.com/controlplaneio/simulator/v2/internal/logging"
 )
 
 func main() {
@@ -21,9 +20,6 @@ func main() {
 	terraformWorkspaceDir := filepath.Join(simulatorDir, "terraform/workspaces/simulator")
 	ansiblePlaybookDir := filepath.Join(simulatorDir, "ansible/playbooks")
 
-	// configure slog
-	logging.Configure()
-
 	conf := config.Config{}
 	if err := conf.Read(); err != nil {
 		slog.Error("failed to read config", "error", err)
diff --git a/cmd/simulator/main.go b/cmd/simulator/main.go
index 3019032d..0cc9fb53 100644
--- a/cmd/simulator/main.go
+++ b/cmd/simulator/main.go
@@ -13,7 +13,6 @@ import (
 	"github.com/controlplaneio/simulator/v2/internal/cli"
 	"github.com/controlplaneio/simulator/v2/internal/config"
 	"github.com/controlplaneio/simulator/v2/internal/docker"
-	"github.com/controlplaneio/simulator/v2/internal/logging"
 )
 
 const (
@@ -31,8 +30,6 @@ var (
 )
 
 func main() {
-	logging.Configure()
-
 	conf := config.Config{}
 	if err := conf.Read(); err != nil {
 		slog.Error("failed to read config", "error", err)
diff --git a/docs/cli.md b/docs/cli.md
index 96a6b9b3..e820afa4 100644
--- a/docs/cli.md
+++ b/docs/cli.md
@@ -60,3 +60,11 @@ bucket: <your-s3-bucket>
 container:
   image: controlplane/simulator:latest
 ```
+
+## Log level
+
+The default log level is set to `error` by default.
+
+It can be changed using the `--log-level` flag or by setting
+`SIMULATOR_LOG_LEVEL` environment variable to one of
+error, warn, info or debug.
diff --git a/internal/cli/simulator.go b/internal/cli/simulator.go
index cebef0b1..32d64a55 100644
--- a/internal/cli/simulator.go
+++ b/internal/cli/simulator.go
@@ -1,9 +1,17 @@
 package cli
 
 import (
+	"os"
+
+	"github.com/controlplaneio/simulator/v2/internal/logging"
 	"github.com/spf13/cobra"
 )
 
+const (
+	logLevelEnv     = "SIMULATOR_LOG_LEVEL"
+	logLevelDefault = "error"
+)
+
 type SimulatorCmdOptions func(command *cobra.Command)
 
 func NewSimulatorCmd(opts ...SimulatorCmdOptions) *cobra.Command {
@@ -12,9 +20,26 @@ func NewSimulatorCmd(opts ...SimulatorCmdOptions) *cobra.Command {
 		Short: "Simulator CLI",
 	}
 
+	simulator.PersistentFlags().String("log-level", logLevel(), "Log level (error, warn, info, debug)")
+
+	simulator.PersistentPreRun = func(cmd *cobra.Command, _ []string) {
+		logLevel, err := cmd.Flags().GetString("log-level")
+		cobra.CheckErr(err)
+
+		err = logging.Configure(logLevel)
+		cobra.CheckErr(err)
+	}
+
 	for _, opt := range opts {
 		opt(simulator)
 	}
 
 	return simulator
 }
+
+func logLevel() string {
+	if l := os.Getenv(logLevelEnv); len(l) > 0 {
+		return l
+	}
+	return logLevelDefault
+}
diff --git a/internal/logging/factory.go b/internal/logging/factory.go
index 3412dc18..2f544c74 100644
--- a/internal/logging/factory.go
+++ b/internal/logging/factory.go
@@ -1,16 +1,34 @@
 package logging
 
 import (
+	"fmt"
 	"log/slog"
 	"os"
 )
 
-func Configure() {
+func Configure(level string) error {
+	var leveler slog.Leveler
+
+	switch level {
+	case "error":
+		leveler = slog.LevelError
+	case "warn":
+		leveler = slog.LevelWarn
+	case "info":
+		leveler = slog.LevelInfo
+	case "debug":
+		leveler = slog.LevelDebug
+	default:
+		return fmt.Errorf("unsupported log level: " + level)
+	}
+
 	handlerOptions := &slog.HandlerOptions{
 		AddSource: true,
-		Level:     slog.LevelError,
+		Level:     leveler,
 	}
 
 	logger := slog.New(slog.NewTextHandler(os.Stdout, handlerOptions))
 	slog.SetDefault(logger)
+
+	return nil
 }