feat: better debugger (#13)

- create centralized structured logger with rotation
(https://github.com/versenilvis/IRIS/commit/96ad7c95ef0f7a9957b1bbf70bb6c8da3ce28b2e)
- update core lookup and utils to use new logger
(https://github.com/versenilvis/IRIS/commit/8b74b5a9cdc1828cff8c6d0bdaaccbe31da7a00a)
- add log startup metadata and propagate reload flags
(https://github.com/versenilvis/IRIS/commit/31208aa91a58e9e09abbf5497c314f5c961a58e2)
- add log key interceptions and pty events
(https://github.com/versenilvis/IRIS/commit/91ccb92835dd16ee70bf630fe0f267aad93c9db0)
- add test for logger 221a40c893b75e6215787163cd751a4c1cb6c1d8
- secure reload arguments file path to prevent symlink attacks
(https://github.com/versenilvis/IRIS/pull/13/commits/c3eabfda451230e52cb71f0c2a556687f839bd3f)
- close log file on reinitialization to prevent descriptor leak
(https://github.com/versenilvis/IRIS/pull/13/commits/a57d2c9be107a8c6200cf7046cc85b2f58667dce)

tests/logger_test.go

@@ -0,0 +1,91 @@
+package tests
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/versenilvis/iris/logger"
+)
+
+func TestLogger(t *testing.T) {
+	tempDir, err := os.MkdirTemp("", "iris-log-test-*")
+	if err != nil {
+		t.Fatalf("failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	logFilePath := filepath.Join(tempDir, "test.log")
+
+	// test 1: default init sets level to info
+	logger.Init(logFilePath, false)
+	logger.Debugf("this debug msg should not be logged")
+	logger.Infof("this info msg should be logged")
+	logger.Close()
+
+	data, err := os.ReadFile(logFilePath)
+	if err != nil {
+		t.Fatalf("failed to read log file: %v", err)
+	}
+
+	content := string(data)
+	if strings.Contains(content, "this debug msg should not be logged") {
+		t.Errorf("expected debug log to be skipped, got: %s", content)
+	}
+	if !strings.Contains(content, "this info msg should be logged") {
+		t.Errorf("expected info log to be recorded, got: %s", content)
+	}
+	if !strings.Contains(content, "[INFO]") {
+		t.Errorf("expected log to contain INFO tag, got: %s", content)
+	}
+	if !strings.Contains(content, "logger_test.go:") {
+		t.Errorf("expected log to contain caller trace info, got: %s", content)
+	}
+
+	// test 2: override init with debug = true
+	_ = os.Remove(logFilePath)
+	logger.Init(logFilePath, true)
+	logger.Debugf("this debug msg should now be logged")
+	logger.Close()
+
+	data, err = os.ReadFile(logFilePath)
+	if err != nil {
+		t.Fatalf("failed to read log file: %v", err)
+	}
+
+	content = string(data)
+	if !strings.Contains(content, "this debug msg should now be logged") {
+		t.Errorf("expected debug log to be recorded, got: %s", content)
+	}
+	if !strings.Contains(content, "[DEBUG]") {
+		t.Errorf("expected log to contain DEBUG tag, got: %s", content)
+	}
+
+	// test 3: test log rotation to .old
+	// create a large file
+	largeData := make([]byte, 6*1024*1024)
+	err = os.WriteFile(logFilePath, largeData, 0644)
+	if err != nil {
+		t.Fatalf("failed to write large file: %v", err)
+	}
+
+	logger.Init(logFilePath, false)
+	logger.Infof("new log after rotation")
+	logger.Close()
+
+	// check if old file exists and is rotated
+	oldPath := logFilePath + ".old"
+	if _, err = os.Stat(oldPath); os.IsNotExist(err) {
+		t.Errorf("expected rotated log file to exist at %s", oldPath)
+	}
+
+	data, err = os.ReadFile(logFilePath)
+	if err != nil {
+		t.Fatalf("failed to read log file: %v", err)
+	}
+	content = string(data)
+	if !strings.Contains(content, "new log after rotation") {
+		t.Errorf("expected new log to exist in the fresh log file, got: %s", content)
+	}
+}