From 8d8415ee469181ea15998da333358c83aa150e8e Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Sun, 25 Jul 2021 20:45:42 -0700
Subject: [PATCH] libct/logs: remove ConfigureLogging

Previous commits removed all its users -- the only one left is package's
own unit tests.

Modify those unit tests to configure logrus directly, and remove
ConfigureLogging for good. The world is better without it.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
---
 libcontainer/logs/logs.go            | 55 ----------------------------
 libcontainer/logs/logs_linux_test.go | 35 +++++++-----------
 2 files changed, 13 insertions(+), 77 deletions(-)

diff --git a/libcontainer/logs/logs.go b/libcontainer/logs/logs.go
index 07592176b..e625abc74 100644
--- a/libcontainer/logs/logs.go
+++ b/libcontainer/logs/logs.go
@@ -3,30 +3,11 @@ package logs
 import (
 	"bufio"
 	"encoding/json"
-	"errors"
-	"fmt"
 	"io"
-	"os"
-	"sync"
 
 	"github.com/sirupsen/logrus"
 )
 
-var (
-	configureMutex sync.Mutex
-	// loggingConfigured will be set once logging has been configured via invoking `ConfigureLogging`.
-	// Subsequent invocations of `ConfigureLogging` would be no-op
-	loggingConfigured = false
-)
-
-type Config struct {
-	LogLevel    logrus.Level
-	LogFormat   string
-	LogFilePath string
-	LogPipeFd   int
-	LogCaller   bool
-}
-
 func ForwardLogs(logPipe io.ReadCloser) chan error {
 	done := make(chan error, 1)
 	s := bufio.NewScanner(logPipe)
@@ -68,39 +49,3 @@ func processEntry(text []byte) {
 	}
 	logrus.StandardLogger().Logf(lvl, jl.Msg)
 }
-
-func ConfigureLogging(config Config) error {
-	configureMutex.Lock()
-	defer configureMutex.Unlock()
-
-	if loggingConfigured {
-		return errors.New("logging has already been configured")
-	}
-
-	logrus.SetLevel(config.LogLevel)
-	logrus.SetReportCaller(config.LogCaller)
-
-	// XXX: while 0 is a valid fd (usually stdin), here we assume
-	// that we never deliberately set LogPipeFd to 0.
-	if config.LogPipeFd > 0 {
-		logrus.SetOutput(os.NewFile(uintptr(config.LogPipeFd), "logpipe"))
-	} else if config.LogFilePath != "" {
-		f, err := os.OpenFile(config.LogFilePath, os.O_CREATE|os.O_WRONLY|os.O_APPEND|os.O_SYNC, 0o644)
-		if err != nil {
-			return err
-		}
-		logrus.SetOutput(f)
-	}
-
-	switch config.LogFormat {
-	case "text":
-		// retain logrus's default.
-	case "json":
-		logrus.SetFormatter(new(logrus.JSONFormatter))
-	default:
-		return fmt.Errorf("unknown log-format %q", config.LogFormat)
-	}
-
-	loggingConfigured = true
-	return nil
-}
diff --git a/libcontainer/logs/logs_linux_test.go b/libcontainer/logs/logs_linux_test.go
index 7e2b59d9c..17bcf6e05 100644
--- a/libcontainer/logs/logs_linux_test.go
+++ b/libcontainer/logs/logs_linux_test.go
@@ -71,7 +71,7 @@ func logToLogWriter(t *testing.T, l *log, message string) {
 
 type log struct {
 	w    io.WriteCloser
-	file string
+	file *os.File
 	done chan error
 }
 
@@ -90,19 +90,16 @@ func runLogForwarding(t *testing.T) *log {
 	if err != nil {
 		t.Fatal(err)
 	}
-	tempFile.Close()
-	logFile := tempFile.Name()
-	t.Cleanup(func() { os.Remove(logFile) })
-
-	logConfig := Config{LogLevel: logrus.InfoLevel, LogFormat: "json", LogFilePath: logFile}
-	loggingConfigured = false
-	if err := ConfigureLogging(logConfig); err != nil {
-		t.Fatal(err)
-	}
+	t.Cleanup(func() {
+		tempFile.Close()
+		os.Remove(tempFile.Name())
+	})
 
+	logrus.SetOutput(tempFile)
+	logrus.SetFormatter(&logrus.JSONFormatter{})
 	doneForwarding := ForwardLogs(logR)
 
-	return &log{w: logW, done: doneForwarding, file: logFile}
+	return &log{w: logW, done: doneForwarding, file: tempFile}
 }
 
 func finish(t *testing.T, l *log) {
@@ -113,16 +110,10 @@ func finish(t *testing.T, l *log) {
 	}
 }
 
-func truncateLogFile(t *testing.T, logFile string) {
+func truncateLogFile(t *testing.T, file *os.File) {
 	t.Helper()
-	file, err := os.OpenFile(logFile, os.O_RDWR, 0o600)
-	if err != nil {
-		t.Fatalf("failed to open log file: %v", err)
-		return
-	}
-	defer file.Close()
 
-	err = file.Truncate(0)
+	err := file.Truncate(0)
 	if err != nil {
 		t.Fatalf("failed to truncate log file: %v", err)
 	}
@@ -131,7 +122,7 @@ func truncateLogFile(t *testing.T, logFile string) {
 // check checks that file contains txt
 func check(t *testing.T, l *log, txt string) {
 	t.Helper()
-	contents, err := ioutil.ReadFile(l.file)
+	contents, err := ioutil.ReadFile(l.file.Name())
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -149,7 +140,7 @@ func checkWait(t *testing.T, l *log, txt string) {
 		iter  = 3
 	)
 	for i := 0; ; i++ {
-		st, err := os.Stat(l.file)
+		st, err := l.file.Stat()
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -157,7 +148,7 @@ func checkWait(t *testing.T, l *log, txt string) {
 			break
 		}
 		if i == iter {
-			t.Fatalf("waited %s for file %s to be non-empty but it still is", iter*delay, l.file)
+			t.Fatalf("waited %s for file %s to be non-empty but it still is", iter*delay, l.file.Name())
 		}
 		time.Sleep(delay)
 	}