From df52d638541d8199cd79b4be42647976447fecbc Mon Sep 17 00:00:00 2001
From: Andrey Vagin <avagin@openvz.org>
Date: Wed, 28 Jan 2015 12:11:19 +0300
Subject: [PATCH] namespaces: send config, network state and other arguments in
 one packet

Signed-off-by: Andrey Vagin <avagin@openvz.org>
---
 namespaces/exec.go | 37 ++++++++++---------------------------
 namespaces/init.go | 27 ++++++++++-----------------
 2 files changed, 20 insertions(+), 44 deletions(-)

diff --git a/namespaces/exec.go b/namespaces/exec.go
index 0c0f6cf6c..1c157e3a2 100644
--- a/namespaces/exec.go
+++ b/namespaces/exec.go
@@ -68,18 +68,8 @@ func executeSetupCmd(args []string, ppid int, container *configs.Config, process
 		return terr
 	}
 
-	encoder := json.NewEncoder(parent)
-
-	if err := encoder.Encode(container); err != nil {
-		return terminate(err)
-	}
-
-	if err := encoder.Encode(process); err != nil {
-		return terminate(err)
-	}
-
 	// send the state to the container's init process then shutdown writes for the parent
-	if err := encoder.Encode(networkState); err != nil {
+	if err := json.NewEncoder(parent).Encode(process); err != nil {
 		return terminate(err)
 	}
 
@@ -158,21 +148,6 @@ func Exec(args []string, env []string, console string, command *exec.Cmd, contai
 		return terr
 	}
 
-	encoder := json.NewEncoder(parent)
-
-	if err := encoder.Encode(container); err != nil {
-		return terminate(err)
-	}
-
-	process := processArgs{
-		Env:         append(env[0:], container.Env...),
-		Args:        args,
-		ConsolePath: console,
-	}
-	if err := encoder.Encode(process); err != nil {
-		return terminate(err)
-	}
-
 	started, err := system.GetProcessStartTime(command.Process.Pid)
 	if err != nil {
 		return terminate(err)
@@ -195,6 +170,14 @@ func Exec(args []string, env []string, console string, command *exec.Cmd, contai
 		return terminate(err)
 	}
 
+	process := processArgs{
+		Env:          append(env[0:], container.Env...),
+		Args:         args,
+		ConsolePath:  console,
+		Config:       container,
+		NetworkState: &networkState,
+	}
+
 	// Start the setup process to setup the init process
 	if container.Namespaces.Contains(configs.NEWUSER) {
 		if err = executeSetupCmd(command.Args, command.Process.Pid, container, &process, &networkState); err != nil {
@@ -203,7 +186,7 @@ func Exec(args []string, env []string, console string, command *exec.Cmd, contai
 	}
 
 	// send the state to the container's init process then shutdown writes for the parent
-	if err := encoder.Encode(networkState); err != nil {
+	if err := json.NewEncoder(parent).Encode(process); err != nil {
 		return terminate(err)
 	}
 	// shutdown writes for the parent side of the pipe
diff --git a/namespaces/init.go b/namespaces/init.go
index 01f721141..5af898e18 100644
--- a/namespaces/init.go
+++ b/namespaces/init.go
@@ -26,9 +26,11 @@ import (
 
 // Process is used for transferring parameters from Exec() to Init()
 type processArgs struct {
-	Args        []string `json:"args,omitempty"`
-	Env         []string `json:"environment,omitempty"`
-	ConsolePath string   `json:"console_path,omitempty"`
+	Args         []string              `json:"args,omitempty"`
+	Env          []string              `json:"environment,omitempty"`
+	ConsolePath  string                `json:"console_path,omitempty"`
+	Config       *configs.Config       `json:"config,omitempty"`
+	NetworkState *network.NetworkState `json:"network_state,omitempty"`
 }
 
 // TODO(vishh): This is part of the libcontainer API and it does much more than just namespaces related work.
@@ -55,29 +57,20 @@ func Init(pipe *os.File, setupUserns bool) (err error) {
 		pipe.Close()
 	}()
 
-	decoder := json.NewDecoder(pipe)
-
-	var container *configs.Config
-	if err := decoder.Decode(&container); err != nil {
-		return err
-	}
-
-	var process *processArgs
-	if err := decoder.Decode(&process); err != nil {
-		return err
-	}
-
 	uncleanRootfs, err := os.Getwd()
 	if err != nil {
 		return err
 	}
 
+	var process *processArgs
 	// We always read this as it is a way to sync with the parent as well
-	var networkState *network.NetworkState
-	if err := decoder.Decode(&networkState); err != nil {
+	if err := json.NewDecoder(pipe).Decode(&process); err != nil {
 		return err
 	}
 
+	container := process.Config
+	networkState := process.NetworkState
+
 	if setupUserns {
 		err = SetupContainer(container, networkState, process.ConsolePath)
 		if err == nil {