From d92fe4f6a1b63e9766d1649d5a16d72fbe22cbd2 Mon Sep 17 00:00:00 2001
From: Drew Erny <drew.erny@docker.com>
Date: Fri, 9 Feb 2018 15:10:58 -0800
Subject: [PATCH] Fix TLS from environment variables in client

A recent change accidently caused any TLS configuration in FromEnv to be
ignored. This change alters WithHost to create a new http client only if
one doesn't already exist, and otherwise applies the logic to the
transport on the existing client. This preserves the TLS configuration
that might already be on the client.

Signed-off-by: Drew Erny <drew.erny@docker.com>
Upstream-commit: 80904e9571e7724328160c97ede6a71864f3c06a
Component: engine
---
 components/engine/client/client.go | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/components/engine/client/client.go b/components/engine/client/client.go
index 240e32ae05..6ce0cdba1f 100644
--- a/components/engine/client/client.go
+++ b/components/engine/client/client.go
@@ -133,23 +133,15 @@ func FromEnv(c *Client) error {
 			},
 			CheckRedirect: CheckRedirect,
 		}
+		WithHTTPClient(httpClient)(c)
 	}
 
 	host := os.Getenv("DOCKER_HOST")
 	if host != "" {
-		var err error
+		// WithHost will create an API client if it doesn't exist
 		if err := WithHost(host)(c); err != nil {
 			return err
 		}
-		httpClient, err = defaultHTTPClient(host)
-		if err != nil {
-			return err
-		}
-	}
-	if httpClient != nil {
-		if err := WithHTTPClient(httpClient)(c); err != nil {
-			return err
-		}
 	}
 	version := os.Getenv("DOCKER_API_VERSION")
 	if version != "" {
@@ -167,7 +159,8 @@ func WithVersion(version string) func(*Client) error {
 	}
 }
 
-// WithHost overrides the client host with the specified one
+// WithHost overrides the client host with the specified one, creating a new
+// http client if one doesn't exist
 func WithHost(host string) func(*Client) error {
 	return func(c *Client) error {
 		hostURL, err := ParseHostURL(host)
@@ -178,11 +171,17 @@ func WithHost(host string) func(*Client) error {
 		c.proto = hostURL.Scheme
 		c.addr = hostURL.Host
 		c.basePath = hostURL.Path
-		client, err := defaultHTTPClient(host)
-		if err != nil {
-			return err
+		if c.client == nil {
+			client, err := defaultHTTPClient(host)
+			if err != nil {
+				return err
+			}
+			return WithHTTPClient(client)(c)
 		}
-		return WithHTTPClient(client)(c)
+		if transport, ok := c.client.Transport.(*http.Transport); ok {
+			return sockets.ConfigureTransport(transport, c.proto, c.addr)
+		}
+		return fmt.Errorf("cannot apply host to http transport")
 	}
 }