From 1c263a7d5e114583972e54b32464044b72d568fb Mon Sep 17 00:00:00 2001
From: Michael Crosby <crosbymichael@gmail.com>
Date: Thu, 26 Apr 2018 15:23:23 -0400
Subject: [PATCH] Add LogFile as a cio IO option

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
---
 cio/io.go | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/cio/io.go b/cio/io.go
index a49c11735..2f9b5f103 100644
--- a/cio/io.go
+++ b/cio/io.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 	"sync"
 
 	"github.com/containerd/containerd/defaults"
@@ -213,3 +214,44 @@ type DirectIO struct {
 }
 
 var _ IO = &DirectIO{}
+
+// LogFile creates a file on disk that logs the task's STDOUT,STDERR.
+// If the log file already exists, the logs will be appended to the file.
+func LogFile(path string) Creator {
+	return func(_ string) (IO, error) {
+		if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+			return nil, err
+		}
+		f, err := os.OpenFile(path, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+		if err != nil {
+			return nil, err
+		}
+		f.Close()
+		return &logIO{
+			config: Config{
+				Stdout: path,
+				Stderr: path,
+			},
+		}, nil
+	}
+}
+
+type logIO struct {
+	config Config
+}
+
+func (l *logIO) Config() Config {
+	return l.config
+}
+
+func (l *logIO) Cancel() {
+
+}
+
+func (l *logIO) Wait() {
+
+}
+
+func (l *logIO) Close() error {
+	return nil
+}