cli/command/container: add completion for --stop-signal

With this patch:

    docker run --stop-signal <TAB>
    ABRT  IOT      RTMAX-4   RTMIN     RTMIN+11  TSTP
    ALRM  KILL     RTMAX-5   RTMIN+1   RTMIN+12  TTIN
    BUS   PIPE     RTMAX-6   RTMIN+2   RTMIN+13  TTOU
    CHLD  POLL     RTMAX-7   RTMIN+3   RTMIN+14  URG
    CLD   PROF     RTMAX-8   RTMIN+4   RTMIN+15  USR1
    CONT  PWR      RTMAX-9   RTMIN+5   SEGV      USR2
    FPE   QUIT     RTMAX-10  RTMIN+6   STKFLT    VTALRM
    HUP   RTMAX    RTMAX-11  RTMIN+7   STOP      WINCH
    ILL   RTMAX-1  RTMAX-12  RTMIN+8   SYS       XCPU
    INT   RTMAX-2  RTMAX-13  RTMIN+9   TERM      XFSZ
    IO    RTMAX-3  RTMAX-14  RTMIN+10  TRAP

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit b1c0ddca02)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/container/completion.go

@@ -3,6 +3,7 @@ package container
 import (
 	"github.com/docker/cli/cli/command/completion"
 	"github.com/docker/docker/api/types/container"
+	"github.com/moby/sys/signal"
 	"github.com/spf13/cobra"
 )
 
@@ -82,3 +83,12 @@ func completeLinuxCapabilityNames(cmd *cobra.Command, args []string, toComplete
 func completeRestartPolicies(cmd *cobra.Command, args []string, toComplete string) (names []string, _ cobra.ShellCompDirective) {
 	return completion.FromList(restartPolicies...)(cmd, args, toComplete)
 }
+
+func completeSignals(cmd *cobra.Command, args []string, toComplete string) (names []string, _ cobra.ShellCompDirective) {
+	// TODO(thaJeztah): do we want to provide the full list here, or a subset?
+	signalNames := make([]string, 0, len(signal.SignalMap))
+	for k := range signal.SignalMap {
+		signalNames = append(signalNames, k)
+	}
+	return completion.FromList(signalNames...)(cmd, args, toComplete)
+}

cli/command/container/create.go

@@ -85,6 +85,7 @@ func NewCreateCommand(dockerCli command.Cli) *cobra.Command {
 	_ = cmd.RegisterFlagCompletionFunc("network", completion.NetworkNames(dockerCli))
 	_ = cmd.RegisterFlagCompletionFunc("pull", completion.FromList(PullImageAlways, PullImageMissing, PullImageNever))
 	_ = cmd.RegisterFlagCompletionFunc("restart", completeRestartPolicies)
+	_ = cmd.RegisterFlagCompletionFunc("stop-signal", completeSignals)
 	_ = cmd.RegisterFlagCompletionFunc("volumes-from", completion.ContainerNames(dockerCli, true))
 	return cmd
 }

cli/command/container/kill.go

@@ -38,6 +38,9 @@ func NewKillCommand(dockerCli command.Cli) *cobra.Command {
 
 	flags := cmd.Flags()
 	flags.StringVarP(&opts.signal, "signal", "s", "", "Signal to send to the container")
+
+	_ = cmd.RegisterFlagCompletionFunc("signal", completeSignals)
+
 	return cmd
 }
 
@@ -50,7 +53,7 @@ func runKill(ctx context.Context, dockerCli command.Cli, opts *killOptions) erro
 		if err := <-errChan; err != nil {
 			errs = append(errs, err.Error())
 		} else {
-			fmt.Fprintln(dockerCli.Out(), name)
+			_, _ = fmt.Fprintln(dockerCli.Out(), name)
 		}
 	}
 	if len(errs) > 0 {

cli/command/container/restart.go

@@ -43,6 +43,9 @@ func NewRestartCommand(dockerCli command.Cli) *cobra.Command {
 	flags := cmd.Flags()
 	flags.StringVarP(&opts.signal, "signal", "s", "", "Signal to send to the container")
 	flags.IntVarP(&opts.timeout, "time", "t", 0, "Seconds to wait before killing the container")
+
+	_ = cmd.RegisterFlagCompletionFunc("signal", completeSignals)
+
 	return cmd
 }
 

cli/command/container/run.go

@@ -76,6 +76,7 @@ func NewRunCommand(dockerCli command.Cli) *cobra.Command {
 	_ = cmd.RegisterFlagCompletionFunc("network", completion.NetworkNames(dockerCli))
 	_ = cmd.RegisterFlagCompletionFunc("pull", completion.FromList(PullImageAlways, PullImageMissing, PullImageNever))
 	_ = cmd.RegisterFlagCompletionFunc("restart", completeRestartPolicies)
+	_ = cmd.RegisterFlagCompletionFunc("stop-signal", completeSignals)
 	_ = cmd.RegisterFlagCompletionFunc("volumes-from", completion.ContainerNames(dockerCli, true))
 	return cmd
 }

cli/command/container/stop.go

@@ -43,6 +43,9 @@ func NewStopCommand(dockerCli command.Cli) *cobra.Command {
 	flags := cmd.Flags()
 	flags.StringVarP(&opts.signal, "signal", "s", "", "Signal to send to the container")
 	flags.IntVarP(&opts.timeout, "time", "t", 0, "Seconds to wait before killing the container")
+
+	_ = cmd.RegisterFlagCompletionFunc("signal", completeSignals)
+
 	return cmd
 }