From 74804559c8d7be6503a0c9647b2acede952c199f Mon Sep 17 00:00:00 2001
From: Shlomi Noach <shlomi-noach@github.com>
Date: Fri, 22 Jul 2016 17:34:18 +0200
Subject: [PATCH] supporting --initially-drop-socket-file - by default gh-ost
 will not delete an existing socket file   and thus, will fail running if
 socket file exists. This is the desired behavior. - The flag
 --initially-drop-socket-file indicates we take responsibility and wish gh-ost
 to delete this file on startup

---
 build.sh              | 2 +-
 go/base/context.go    | 1 +
 go/cmd/gh-ost/main.go | 1 +
 go/logic/server.go    | 2 +-
 4 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/build.sh b/build.sh
index b834412..5303130 100644
--- a/build.sh
+++ b/build.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 #
 #
-RELEASE_VERSION="1.0.2"
+RELEASE_VERSION="1.0.3"
 
 buildpath=/tmp/gh-ost
 target=gh-ost
diff --git a/go/base/context.go b/go/base/context.go
index 00a5ad7..ebfcd85 100644
--- a/go/base/context.go
+++ b/go/base/context.go
@@ -72,6 +72,7 @@ type MigrationContext struct {
 	CutOverLockTimeoutSeconds           int64
 	PanicFlagFile                       string
 
+	DropServeSocket bool
 	ServeSocketFile string
 	ServeTCPPort    int64
 
diff --git a/go/cmd/gh-ost/main.go b/go/cmd/gh-ost/main.go
index ac4796b..b25e7c2 100644
--- a/go/cmd/gh-ost/main.go
+++ b/go/cmd/gh-ost/main.go
@@ -83,6 +83,7 @@ func main() {
 	flag.StringVar(&migrationContext.PostponeCutOverFlagFile, "postpone-cut-over-flag-file", "", "while this file exists, migration will postpone the final stage of swapping tables, and will keep on syncing the ghost table. Cut-over/swapping would be ready to perform the moment the file is deleted.")
 	flag.StringVar(&migrationContext.PanicFlagFile, "panic-flag-file", "", "when this file is created, gh-ost will immediately terminate, without cleanup")
 
+	flag.BoolVar(&migrationContext.DropServeSocket, "initially-drop-socket-file", false, "Should gh-ost forcibly delete an existing socket file. Be careful: this might drop the socket file of a running migration!")
 	flag.StringVar(&migrationContext.ServeSocketFile, "serve-socket-file", "", "Unix socket file to serve on. Default: auto-determined and advertised upon startup")
 	flag.Int64Var(&migrationContext.ServeTCPPort, "serve-tcp-port", 0, "TCP port to serve on. Default: disabled")
 
diff --git a/go/logic/server.go b/go/logic/server.go
index 6d67859..f216af6 100644
--- a/go/logic/server.go
+++ b/go/logic/server.go
@@ -36,7 +36,7 @@ func (this *Server) BindSocketFile() (err error) {
 	if this.migrationContext.ServeSocketFile == "" {
 		return nil
 	}
-	if base.FileExists(this.migrationContext.ServeSocketFile) {
+	if this.migrationContext.DropServeSocket && base.FileExists(this.migrationContext.ServeSocketFile) {
 		os.Remove(this.migrationContext.ServeSocketFile)
 	}
 	this.unixListener, err = net.Listen("unix", this.migrationContext.ServeSocketFile)