completion: add completion for node names

Change completion for nodes to use names by default, and bring back
support for the `DOCKER_COMPLETION_SHOW_NODE_IDS` env-var
f9ced58158/contrib/completion/bash/docker (L38)

With this patch:

    docker node ps <tab>
    docker-desktop            self

    export DOCKER_COMPLETION_SHOW_NODE_IDS=yes
    docker node ps <TAB>
    docker-desktop             qyeriqk20al6hy4y869d08ff5  self

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/node/completion.go

@@ -0,0 +1,37 @@
+package node
+
+import (
+	"os"
+
+	"github.com/docker/cli/cli/command/completion"
+	"github.com/docker/docker/api/types"
+	"github.com/spf13/cobra"
+)
+
+// completeNodeNames offers completion for swarm node (host)names and optional IDs.
+// By default, only names are returned.
+// Set DOCKER_COMPLETION_SHOW_NODE_IDS=yes to also complete IDs.
+//
+// TODO(thaJeztah): add support for filters.
+func completeNodeNames(dockerCLI completion.APIClientProvider) completion.ValidArgsFn {
+	// https://github.com/docker/cli/blob/f9ced58158d5e0b358052432244b483774a1983d/contrib/completion/bash/docker#L41-L43
+	showIDs := os.Getenv("DOCKER_COMPLETION_SHOW_NODE_IDS") == "yes"
+	return func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		list, err := dockerCLI.Client().NodeList(cmd.Context(), types.NodeListOptions{})
+		if err != nil {
+			return nil, cobra.ShellCompDirectiveError
+		}
+
+		names := make([]string, 0, len(list)+1)
+		for _, node := range list {
+			if showIDs {
+				names = append(names, node.Description.Hostname, node.ID)
+			} else {
+				names = append(names, node.Description.Hostname)
+			}
+		}
+		// Nodes allow "self" as magic word for the current node.
+		names = append(names, "self")
+		return names, cobra.ShellCompDirectiveNoFileComp
+	}
+}

cli/command/node/demote.go

@@ -18,6 +18,7 @@ func newDemoteCommand(dockerCli command.Cli) *cobra.Command {
 		RunE: func(cmd *cobra.Command, args []string) error {
 			return runDemote(cmd.Context(), dockerCli, args)
 		},
+		ValidArgsFunction: completeNodeNames(dockerCli),
 	}
 }
 

cli/command/node/inspect.go

@@ -32,6 +32,7 @@ func newInspectCommand(dockerCli command.Cli) *cobra.Command {
 			opts.nodeIds = args
 			return runInspect(cmd.Context(), dockerCli, opts)
 		},
+		ValidArgsFunction: completeNodeNames(dockerCli),
 	}
 
 	flags := cmd.Flags()

cli/command/node/promote.go

@@ -18,6 +18,7 @@ func newPromoteCommand(dockerCli command.Cli) *cobra.Command {
 		RunE: func(cmd *cobra.Command, args []string) error {
 			return runPromote(cmd.Context(), dockerCli, args)
 		},
+		ValidArgsFunction: completeNodeNames(dockerCli),
 	}
 }
 

cli/command/node/ps.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
-	"github.com/docker/cli/cli/command/completion"
 	"github.com/docker/cli/cli/command/idresolver"
 	"github.com/docker/cli/cli/command/task"
 	"github.com/docker/cli/opts"
@@ -41,7 +40,7 @@ func newPsCommand(dockerCli command.Cli) *cobra.Command {
 
 			return runPs(cmd.Context(), dockerCli, options)
 		},
-		ValidArgsFunction: completion.NoComplete,
+		ValidArgsFunction: completeNodeNames(dockerCli),
 	}
 	flags := cmd.Flags()
 	flags.BoolVar(&options.noTrunc, "no-trunc", false, "Do not truncate output")

cli/command/node/remove.go

@@ -26,6 +26,7 @@ func newRemoveCommand(dockerCli command.Cli) *cobra.Command {
 		RunE: func(cmd *cobra.Command, args []string) error {
 			return runRemove(cmd.Context(), dockerCli, args, opts)
 		},
+		ValidArgsFunction: completeNodeNames(dockerCli),
 	}
 	flags := cmd.Flags()
 	flags.BoolVarP(&opts.force, "force", "f", false, "Force remove a node from the swarm")

cli/command/node/update.go

@@ -25,6 +25,7 @@ func newUpdateCommand(dockerCli command.Cli) *cobra.Command {
 		RunE: func(cmd *cobra.Command, args []string) error {
 			return runUpdate(cmd.Context(), dockerCli, cmd.Flags(), args[0])
 		},
+		ValidArgsFunction: completeNodeNames(dockerCli),
 	}
 
 	flags := cmd.Flags()