restore support for env variables to configure proxy

regression introduced by b34f34
close #39654

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>
(cherry picked from commit e25e077a20)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/cli_test.go

@@ -6,6 +6,7 @@ import (
 	"crypto/x509"
 	"fmt"
 	"io/ioutil"
+	"net/http"
 	"os"
 	"runtime"
 	"testing"
@@ -79,6 +80,24 @@ func TestNewAPIClientFromFlagsWithAPIVersionFromEnv(t *testing.T) {
 	assert.Check(t, is.Equal(customVersion, apiclient.ClientVersion()))
 }
 
+func TestNewAPIClientFromFlagsWithHttpProxyEnv(t *testing.T) {
+	defer env.Patch(t, "HTTP_PROXY", "http://proxy.acme.com:1234")()
+	defer env.Patch(t, "DOCKER_HOST", "tcp://docker.acme.com:2376")()
+
+	opts := &flags.CommonOptions{}
+	configFile := &configfile.ConfigFile{}
+	apiclient, err := NewAPIClientFromFlags(opts, configFile)
+	assert.NilError(t, err)
+	transport, ok := apiclient.HTTPClient().Transport.(*http.Transport)
+	assert.Assert(t, ok)
+	assert.Assert(t, transport.Proxy != nil)
+	request, err := http.NewRequest(http.MethodGet, "tcp://docker.acme.com:2376", nil)
+	assert.NilError(t, err)
+	url, err := transport.Proxy(request)
+	assert.NilError(t, err)
+	assert.Check(t, is.Equal("http://proxy.acme.com:1234", url.String()))
+}
+
 type fakeClient struct {
 	client.Client
 	pingFunc   func() (types.Ping, error)

cli/context/docker/load.go

@@ -104,8 +104,8 @@ func (c *Endpoint) ClientOpts() ([]client.Opt, error) {
 				return nil, err
 			}
 			result = append(result,
-				client.WithHost(c.Host),
 				withHTTPClient(tlsConfig),
+				client.WithHost(c.Host),
 			)
 
 		} else {