[client] Prevent corruption from competing log rotation and improve debug bundle (#6214)

* Adds heuristic to detect an edge case on Linux where a system has configured logrotate as a separate service to rotate log files which would mangle our client log files. If we detect logrotate being configured for netbird, we disable our rotation.

* Adds new env var to disable log rotation: NB_LOG_DISABLE_ROTATION

* Adds compressed and plain logrotate files to debug bundle.

* Replaces lumberjack with timberjack (maintained fork with bug fixes and extra features).

* Clarifies which daemon version is running in the bundle stats.

* Change logging for client service status to console

util/logrotate_linux.go

@@ -0,0 +1,93 @@
+//go:build linux
+
+package util
+
+import (
+	"bufio"
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	defaultLogrotateConfPath = "/etc/logrotate.conf"
+	defaultLogrotateConfDir  = "/etc/logrotate.d"
+	netbirdString            = "netbird"
+)
+
+// FindLogrotateConflicts scans the standard logrotate locations for
+// indications of conflict with netbird. It returns true and the config file
+// path if a conflict was found.
+func FindFirstLogrotateConflict() (bool, string) {
+	return findFirstLogrotateConflictIn(defaultLogrotateConfPath, defaultLogrotateConfDir)
+}
+
+func findFirstLogrotateConflictIn(confPath, confDir string) (bool, string) {
+	for _, f := range listLogrotateConfigs(confPath, confDir) {
+		present, err := scanLogrotateFile(f, netbirdString)
+		if err != nil {
+			if !errors.Is(err, fs.ErrNotExist) {
+				log.Debugf("scan %s: %v", f, err)
+			}
+			continue
+		}
+		if present {
+			return present, f
+		}
+	}
+	return false, ""
+}
+
+// listLogrotateConfigs returns all config files for logrotate.
+func listLogrotateConfigs(confPath, confDir string) []string {
+	files := []string{confPath}
+	entries, err := os.ReadDir(confDir)
+	if err != nil {
+		return files
+	}
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+		files = append(files, filepath.Join(confDir, e.Name()))
+	}
+	return files
+}
+
+// scanLogrotateFile reads a config and reports if a non-comment line
+// contains the given substring.
+func scanLogrotateFile(path string, substring string) (bool, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return false, err
+	}
+	defer func() {
+		if err := f.Close(); err != nil {
+			log.Debugf("close %s: %v", path, err)
+		}
+	}()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := strings.TrimSpace(stripLogrotateComment(scanner.Text()))
+		if line == "" {
+			continue
+		}
+		if strings.Contains(line, substring) {
+			return true, nil
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return false, err
+	}
+	return false, nil
+}
+
+func stripLogrotateComment(line string) string {
+	before, _, _ := strings.Cut(line, "#")
+	return before
+}