From 1d2208fed90da9ab72ded3b1c65bb2a71b66ce93 Mon Sep 17 00:00:00 2001
From: Zhang Wei <zhangwei555@huawei.com>
Date: Mon, 25 Jan 2016 23:38:03 +0800
Subject: [PATCH] Forbid exec a restarting container

Currently if we exec a restarting container, client will fail silently,
and daemon will print error that container can't be found which is not a
very meaningful prompt to user.

This commit will stop user from exec a restarting container and gives
more explicit error message.

Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
---
 container/state.go | 8 ++++++++
 daemon/exec.go     | 6 ++++++
 errors/daemon.go   | 9 +++++++++
 3 files changed, 23 insertions(+)

diff --git a/container/state.go b/container/state.go
index 138d79874f..4a923aa968 100644
--- a/container/state.go
+++ b/container/state.go
@@ -247,6 +247,14 @@ func (s *State) IsPaused() bool {
 	return res
 }
 
+// IsRestarting returns whether the container is restarting or not.
+func (s *State) IsRestarting() bool {
+	s.Lock()
+	res := s.Restarting
+	s.Unlock()
+	return res
+}
+
 // SetRemovalInProgress sets the container state as being removed.
 func (s *State) SetRemovalInProgress() error {
 	s.Lock()
diff --git a/daemon/exec.go b/daemon/exec.go
index 4dba7c9d47..7772790d6e 100644
--- a/daemon/exec.go
+++ b/daemon/exec.go
@@ -52,6 +52,9 @@ func (d *Daemon) getExecConfig(name string) (*exec.Config, error) {
 			if container.IsPaused() {
 				return nil, derr.ErrorCodeExecPaused.WithArgs(container.ID)
 			}
+			if container.IsRestarting() {
+				return nil, derr.ErrorCodeExecRestarting.WithArgs(container.ID)
+			}
 			return ec, nil
 		}
 	}
@@ -76,6 +79,9 @@ func (d *Daemon) getActiveContainer(name string) (*container.Container, error) {
 	if container.IsPaused() {
 		return nil, derr.ErrorCodeExecPaused.WithArgs(name)
 	}
+	if container.IsRestarting() {
+		return nil, derr.ErrorCodeExecRestarting.WithArgs(name)
+	}
 	return container, nil
 }
 
diff --git a/errors/daemon.go b/errors/daemon.go
index a2caabb16b..78c4422ab1 100644
--- a/errors/daemon.go
+++ b/errors/daemon.go
@@ -733,6 +733,15 @@ var (
 		HTTPStatusCode: http.StatusConflict,
 	})
 
+	// ErrorCodeExecRestarting is generated when we try to start an exec
+	// but the container is restarting.
+	ErrorCodeExecRestarting = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:          "EXECRESTARTING",
+		Message:        "Container %s is restarting, wait until the container is running",
+		Description:    "An attempt to start an 'exec' was made, but the owning container is restarting",
+		HTTPStatusCode: http.StatusConflict,
+	})
+
 	// ErrorCodeExecRunning is generated when we try to start an exec
 	// but its already running.
 	ErrorCodeExecRunning = errcode.Register(errGroup, errcode.ErrorDescriptor{