Add -H flag to our own version command & login command, & also —-log-level (-l) flag.

cli/cmd/login/login.go

@@ -21,6 +21,8 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/docker/api/cli/cmd/mobyflags"
+
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 
@@ -43,6 +45,7 @@ func Command() *cobra.Command {
 	flags.StringP("username", "u", "", "Username")
 	flags.StringP("password", "p", "", "Password")
 	flags.BoolP("password-stdin", "", false, "Take the password from stdin")
+	mobyflags.AddMobyFlagsForRetrocompatibility(flags)
 
 	return cmd
 }

cli/cmd/mobyflags/mobyflags.go

@@ -0,0 +1,24 @@
+package mobyflags
+
+import (
+	"log"
+
+	flag "github.com/spf13/pflag"
+)
+
+// AddMobyFlagsForRetrocompatibility adds retrocompatibility flags to our commands
+func AddMobyFlagsForRetrocompatibility(flags *flag.FlagSet) {
+	const hostFlag = "host"
+	flags.StringP(hostFlag, "H", "", "Daemon socket(s) to connect to")
+	markHidden(flags, hostFlag)
+	const logLevelFlag = "log-level"
+	flags.StringP(logLevelFlag, "l", "info", `Set the logging level ("debug"|"info"|"warn"|"error"|"fatal")`)
+	markHidden(flags, logLevelFlag)
+}
+
+func markHidden(flags *flag.FlagSet, flagName string) {
+	err := flags.MarkHidden(flagName)
+	if err != nil {
+		log.Fatal(err)
+	}
+}

cli/cmd/version.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/docker/api/cli/cmd/mobyflags"
 	"github.com/docker/api/cli/mobycli"
 )
 
@@ -39,6 +40,7 @@ func VersionCommand() *cobra.Command {
 	flags := cmd.Flags()
 	flags.String("format", "", "Format the output using the given Go template")
 	flags.String("kubeconfig", "", "Kubernetes config file")
+	mobyflags.AddMobyFlagsForRetrocompatibility(flags)
 
 	return cmd
 }

tests/e2e/e2e_test.go

@@ -173,6 +173,23 @@ func (s *E2eSuite) TestLeaveLegacyErrorMessagesUnchanged() {
 	Expect(err).NotTo(BeNil())
 }
 
+func (s *E2eSuite) TestPassThroughRootLegacyFlags() {
+	output, err := s.NewDockerCommand("-H", "tcp://localhost:123", "version").Exec()
+	Expect(err).To(BeNil())
+	Expect(output).To(ContainSubstring("Client:"))
+	Expect(output).To(ContainSubstring("localhost:123"))
+
+	output, _ = s.NewDockerCommand("-H", "tcp://localhost:123", "login", "-u", "nouser", "-p", "wrongpasword").Exec()
+	Expect(output).To(ContainSubstring("WARNING! Using --password via the CLI is insecure"))
+
+	output, _ = s.NewDockerCommand("--log-level", "debug", "login", "-u", "nouser", "-p", "wrongpasword").Exec()
+	Expect(output).To(ContainSubstring("WARNING! Using --password via the CLI is insecure"))
+
+	output, _ = s.NewDockerCommand("login", "--help").Exec()
+	Expect(output).NotTo(ContainSubstring("--host"))
+	Expect(output).NotTo(ContainSubstring("--log-level"))
+}
+
 func (s *E2eSuite) TestDisplayFriendlyErrorMessageForLegacyCommands() {
 	s.NewDockerCommand("context", "create", "example", "test-example").ExecOrDie()
 	output, err := s.NewDockerCommand("--context", "test-example", "images").Exec()