Merge pull request #415 from jlhawn/client_dial_enable_tcp_keepalive

Enable TCP Keep-Alive in Docker client
Upstream-commit: f7b78dc137
Component: cli

components/cli/cli/command/cli.go

@@ -2,9 +2,11 @@ package command
 
 import (
 	"io"
+	"net"
 	"net/http"
 	"os"
 	"runtime"
+	"time"
 
 	"github.com/docker/cli/cli"
 	cliconfig "github.com/docker/cli/cli/config"
@@ -214,6 +216,10 @@ func newHTTPClient(host string, tlsOptions *tlsconfig.Options) (*http.Client, er
 	}
 	tr := &http.Transport{
 		TLSClientConfig: config,
+		DialContext: (&net.Dialer{
+			KeepAlive: 30 * time.Second,
+			Timeout:   30 * time.Second,
+		}).DialContext,
 	}
 	proto, addr, _, err := client.ParseHost(host)
 	if err != nil {