From 65121e5fce3851d7d1e8c8cd5d77dd3c9591d773 Mon Sep 17 00:00:00 2001
From: Antonio Murdaca <runcom@linux.com>
Date: Tue, 21 Jul 2015 21:18:56 +0200
Subject: [PATCH] Allow starting a container with an existing hostConfig which
 contains links

Signed-off-by: Antonio Murdaca <runcom@linux.com>
---
 daemon/daemon_unix.go                         |  1 -
 integration-cli/docker_api_containers_test.go | 45 +++++++++++++++++++
 pkg/parsers/parsers.go                        |  8 ++++
 3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/daemon/daemon_unix.go b/daemon/daemon_unix.go
index 49ee833215..286006930b 100644
--- a/daemon/daemon_unix.go
+++ b/daemon/daemon_unix.go
@@ -481,7 +481,6 @@ func (daemon *Daemon) NetworkApiRouter() func(w http.ResponseWriter, req *http.R
 }
 
 func (daemon *Daemon) RegisterLinks(container *Container, hostConfig *runconfig.HostConfig) error {
-
 	if hostConfig == nil || hostConfig.Links == nil {
 		return nil
 	}
diff --git a/integration-cli/docker_api_containers_test.go b/integration-cli/docker_api_containers_test.go
index 9236f88409..d503111734 100644
--- a/integration-cli/docker_api_containers_test.go
+++ b/integration-cli/docker_api_containers_test.go
@@ -1614,3 +1614,48 @@ func (s *DockerSuite) TestPostContainersCreateWithStringOrSliceCapAddDrop(c *che
 	c.Assert(err, check.IsNil)
 	c.Assert(status, check.Equals, http.StatusCreated)
 }
+
+// #14640
+func (s *DockerSuite) TestPostContainersStartWithoutLinksInHostConfig(c *check.C) {
+	name := "test-host-config-links"
+	dockerCmd(c, "create", "--name", name, "busybox", "top")
+
+	hc, err := inspectFieldJSON(name, "HostConfig")
+	c.Assert(err, check.IsNil)
+	config := `{"HostConfig":` + hc + `}`
+
+	res, _, err := sockRequestRaw("POST", "/containers/"+name+"/start", strings.NewReader(config), "application/json")
+	c.Assert(err, check.IsNil)
+	c.Assert(res.StatusCode, check.Equals, http.StatusNoContent)
+}
+
+// #14640
+func (s *DockerSuite) TestPostContainersStartWithLinksInHostConfig(c *check.C) {
+	name := "test-host-config-links"
+	dockerCmd(c, "run", "--name", "foo", "-d", "busybox", "top")
+	dockerCmd(c, "create", "--name", name, "--link", "foo:bar", "busybox", "top")
+
+	hc, err := inspectFieldJSON(name, "HostConfig")
+	c.Assert(err, check.IsNil)
+	config := `{"HostConfig":` + hc + `}`
+
+	res, _, err := sockRequestRaw("POST", "/containers/"+name+"/start", strings.NewReader(config), "application/json")
+	c.Assert(err, check.IsNil)
+	c.Assert(res.StatusCode, check.Equals, http.StatusNoContent)
+}
+
+// #14640
+func (s *DockerSuite) TestPostContainersStartWithLinksInHostConfigIdLinked(c *check.C) {
+	name := "test-host-config-links"
+	out, _ := dockerCmd(c, "run", "--name", "link0", "-d", "busybox", "top")
+	id := strings.TrimSpace(out)
+	dockerCmd(c, "create", "--name", name, "--link", id, "busybox", "top")
+
+	hc, err := inspectFieldJSON(name, "HostConfig")
+	c.Assert(err, check.IsNil)
+	config := `{"HostConfig":` + hc + `}`
+
+	res, _, err := sockRequestRaw("POST", "/containers/"+name+"/start", strings.NewReader(config), "application/json")
+	c.Assert(err, check.IsNil)
+	c.Assert(res.StatusCode, check.Equals, http.StatusNoContent)
+}
diff --git a/pkg/parsers/parsers.go b/pkg/parsers/parsers.go
index e6c8774f50..ef7f942e52 100644
--- a/pkg/parsers/parsers.go
+++ b/pkg/parsers/parsers.go
@@ -3,6 +3,7 @@ package parsers
 import (
 	"fmt"
 	"net/url"
+	"path"
 	"runtime"
 	"strconv"
 	"strings"
@@ -158,5 +159,12 @@ func ParseLink(val string) (string, string, error) {
 	if len(arr) == 1 {
 		return val, val, nil
 	}
+	// This is kept because we can actually get an HostConfig with links
+	// from an already created container and the format is not `foo:bar`
+	// but `/foo:/c1/bar`
+	if strings.HasPrefix(arr[0], "/") {
+		_, alias := path.Split(arr[1])
+		return arr[0][1:], alias, nil
+	}
 	return arr[0], arr[1], nil
 }