From 6f84bf665d3b0daf6acb4641674a479cd0d6a65a Mon Sep 17 00:00:00 2001
From: Christian Schwarz <me@cschwarz.com>
Date: Fri, 12 May 2017 21:11:09 +0200
Subject: [PATCH] cmd: support logging reads & writes from sshbytestream to a
 file.

---
 cmd/config.go |  7 +++++++
 cmd/main.go   |  4 ++--
 util/io.go    | 40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/cmd/config.go b/cmd/config.go
index e1563b1..5b2bcdd 100644
--- a/cmd/config.go
+++ b/cmd/config.go
@@ -7,6 +7,7 @@ import (
 	"github.com/mitchellh/mapstructure"
 	"github.com/zrepl/zrepl/rpc"
 	"github.com/zrepl/zrepl/sshbytestream"
+	. "github.com/zrepl/zrepl/util"
 	"github.com/zrepl/zrepl/zfs"
 	yaml "gopkg.in/yaml.v2"
 	"io"
@@ -37,6 +38,8 @@ type SSHTransport struct {
 	TransportOpenCommand []string `mapstructure:"transport_open_command"`
 	SSHCommand           string   `mapstructure:"ssh_command"`
 	Options              []string
+	ConnLogReadFile      string `mapstructure:"connlog_read_file"`
+	ConnLogWriteFile     string `mapstructure:"connlog_write_file"`
 }
 
 type InitialReplPolicy string
@@ -393,6 +396,10 @@ func (t SSHTransport) Connect() (r rpc.RPCRequester, err error) {
 	if stream, err = sshbytestream.Outgoing(rpcTransport); err != nil {
 		return
 	}
+	stream, err = NewReadWriteCloserLogger(stream, t.ConnLogReadFile, t.ConnLogWriteFile)
+	if err != nil {
+		return
+	}
 	return rpc.ConnectByteStreamRPC(stream)
 }
 
diff --git a/cmd/main.go b/cmd/main.go
index 702f2ae..a50848a 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -148,7 +148,7 @@ func doRun(c *cli.Context) error {
 			Repeats:  true,
 			RunFunc: func(log jobrun.Logger) error {
 				log.Printf("doing pull: %v", pull)
-				return doPull(pull, log)
+				return doPull(pull, c, log)
 			},
 		}
 
@@ -183,7 +183,7 @@ func doRun(c *cli.Context) error {
 	return nil
 }
 
-func doPull(pull Pull, log jobrun.Logger) (err error) {
+func doPull(pull Pull, c *cli.Context, log jobrun.Logger) (err error) {
 
 	if lt, ok := pull.From.Transport.(LocalTransport); ok {
 		lt.SetHandler(Handler{
diff --git a/util/io.go b/util/io.go
index cf10bd1..5010115 100644
--- a/util/io.go
+++ b/util/io.go
@@ -2,8 +2,48 @@ package util
 
 import (
 	"io"
+	"os"
 )
 
+type ReadWriteCloserLogger struct {
+	RWC       io.ReadWriteCloser
+	ReadFile  *os.File
+	WriteFile *os.File
+}
+
+func NewReadWriteCloserLogger(rwc io.ReadWriteCloser, readlog, writelog string) (l *ReadWriteCloserLogger, err error) {
+	l = &ReadWriteCloserLogger{
+		RWC: rwc,
+	}
+	flags := os.O_CREATE | os.O_WRONLY
+	if l.ReadFile, err = os.OpenFile(readlog, flags, 0600); err != nil {
+		return
+	}
+	if l.WriteFile, err = os.OpenFile(writelog, flags, 0600); err != nil {
+		return
+	}
+	return
+}
+
+func (c *ReadWriteCloserLogger) Read(buf []byte) (n int, err error) {
+	n, err = c.RWC.Read(buf)
+	if _, writeErr := c.ReadFile.Write(buf[0:n]); writeErr != nil {
+		panic(writeErr)
+	}
+	return
+}
+
+func (c *ReadWriteCloserLogger) Write(buf []byte) (n int, err error) {
+	n, err = c.RWC.Write(buf)
+	if _, writeErr := c.WriteFile.Write(buf[0:n]); writeErr != nil {
+		panic(writeErr)
+	}
+	return
+}
+func (c *ReadWriteCloserLogger) Close() error {
+	return c.RWC.Close()
+}
+
 type ChainedReader struct {
 	Readers   []io.Reader
 	curReader int