From 012dffeee3d754e61b4e9744d39e8ea573efce41 Mon Sep 17 00:00:00 2001
From: Nishant Totla <nishanttotla@gmail.com>
Date: Tue, 5 Apr 2016 09:17:16 -0700
Subject: [PATCH] Updating apiClient version using server version

Signed-off-by: Nishant Totla <nishanttotla@gmail.com>
---
 api/mockclient/mock.go |  4 ++++
 api/nopclient/nop.go   |  4 ++++
 cluster/engine.go      | 24 +++++++++++++++++++++++-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/api/mockclient/mock.go b/api/mockclient/mock.go
index 2af4969e23..16e25a0e8f 100644
--- a/api/mockclient/mock.go
+++ b/api/mockclient/mock.go
@@ -347,6 +347,10 @@ func (client *MockClient) ServerVersion(ctx context.Context) (types.Version, err
 	return args.Get(0).(types.Version), args.Error(1)
 }
 
+// UpdateClientVersion updates the client version
+func (client *MockClient) UpdateClientVersion(v string) {
+}
+
 // VolumeCreate creates a volume in the docker host
 func (client *MockClient) VolumeCreate(ctx context.Context, options types.VolumeCreateRequest) (types.Volume, error) {
 	args := client.Mock.Called(ctx, options)
diff --git a/api/nopclient/nop.go b/api/nopclient/nop.go
index e5eb024204..f26387d1b6 100644
--- a/api/nopclient/nop.go
+++ b/api/nopclient/nop.go
@@ -297,6 +297,10 @@ func (client *NopClient) ServerVersion(ctx context.Context) (types.Version, erro
 	return types.Version{}, errNoEngine
 }
 
+// UpdateClientVersion updates the client version
+func (client *NopClient) UpdateClientVersion(v string) {
+}
+
 // VolumeCreate creates a volume in the docker host
 func (client *NopClient) VolumeCreate(ctx context.Context, options types.VolumeCreateRequest) (types.Volume, error) {
 	return types.Volume{}, errNoEngine
diff --git a/cluster/engine.go b/cluster/engine.go
index b47eda94a8..4b5d93758e 100644
--- a/cluster/engine.go
+++ b/cluster/engine.go
@@ -414,6 +414,26 @@ func (e *Engine) CheckConnectionErr(err error) {
 	// other errors may be ambiguous.
 }
 
+// Update API Version in apiClient
+func (e *Engine) updateClientVersionFromServer(serverVersion string) {
+	// v will be >= 1.6, since this is checked earlier
+	v := version.Version(serverVersion)
+	switch {
+	case v.LessThan(version.Version("1.7")):
+		e.apiClient.UpdateClientVersion("1.18")
+	case v.LessThan(version.Version("1.8")):
+		e.apiClient.UpdateClientVersion("1.19")
+	case v.LessThan(version.Version("1.9")):
+		e.apiClient.UpdateClientVersion("1.20")
+	case v.LessThan(version.Version("1.10")):
+		e.apiClient.UpdateClientVersion("1.21")
+	case v.LessThan(version.Version("1.11")):
+		e.apiClient.UpdateClientVersion("1.22")
+	default:
+		e.apiClient.UpdateClientVersion("1.23")
+	}
+}
+
 // Gather engine specs (CPU, memory, constraints, ...).
 func (e *Engine) updateSpecs() error {
 	info, err := e.apiClient.Info(context.TODO())
@@ -441,8 +461,10 @@ func (e *Engine) updateSpecs() error {
 		e.CheckConnectionErr(err)
 		return err
 	}
-	// update version
+	// update server version
 	e.Version = v.Version
+	// update client version. engine-api handles backward compatibility where needed
+	e.updateClientVersionFromServer(v.Version)
 
 	e.Lock()
 	defer e.Unlock()