Refactor the stack services command to be uniform

Running `docker stack services <STACK> --orchestrator swarm would yield
the message "Noting found in stack: asdf" with an exit code 0. The same
command with kubernetes orchestrator would yield "nothing found in
stack: adsf" (note the lower-case "nothing") and a non-zero exit code.
This change makes the `stack services` command uniform for both
orchestrators. The logic of getting and printing services is split to
reuse the same formatting code.

Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>

cli/command/stack/kubernetes/services.go

@@ -5,7 +5,6 @@ import (
 	"strings"
 
 	"github.com/docker/cli/cli/command/service"
-	"github.com/docker/cli/cli/command/stack/formatter"
 	"github.com/docker/cli/cli/command/stack/options"
 	"github.com/docker/compose-on-kubernetes/api/labels"
 	"github.com/docker/docker/api/types/filters"
@@ -79,60 +78,47 @@ func getResourcesForServiceList(dockerCli *KubeCli, filters filters.Args, labelS
 	return replicas, daemons, services, nil
 }
 
-// RunServices is the kubernetes implementation of docker stack services
-func RunServices(dockerCli *KubeCli, opts options.Services) error {
+// GetServices is the kubernetes implementation of listing stack services
+func GetServices(dockerCli *KubeCli, opts options.Services) ([]swarm.Service, map[string]service.ListInfo, error) {
 	filters := opts.Filter.Value()
 	if err := filters.Validate(supportedServicesFilters); err != nil {
-		return err
+		return nil, nil, err
 	}
 	client, err := dockerCli.composeClient()
 	if err != nil {
-		return nil
+		return nil, nil, err
 	}
 	stacks, err := client.Stacks(false)
 	if err != nil {
-		return nil
+		return nil, nil, err
 	}
 	stackName := opts.Namespace
 	_, err = stacks.Get(stackName)
 	if apierrs.IsNotFound(err) {
-		return fmt.Errorf("nothing found in stack: %s", stackName)
+		return []swarm.Service{}, nil, nil
 	}
 	if err != nil {
-		return err
+		return nil, nil, err
 	}
 
 	labelSelector := generateLabelSelector(filters, stackName)
 	replicasList, daemonsList, servicesList, err := getResourcesForServiceList(dockerCli, filters, labelSelector)
 	if err != nil {
-		return err
+		return nil, nil, err
 	}
 
 	// Convert Replicas sets and kubernetes services to swarm services and formatter information
 	services, info, err := convertToServices(replicasList, daemonsList, servicesList)
 	if err != nil {
-		return err
+		return nil, nil, err
 	}
 	services = filterServicesByName(services, filters.Get("name"), stackName)
 
 	if opts.Quiet {
 		info = map[string]service.ListInfo{}
 	}
 
-	format := opts.Format
-	if len(format) == 0 {
-		if len(dockerCli.ConfigFile().ServicesFormat) > 0 && !opts.Quiet {
-			format = dockerCli.ConfigFile().ServicesFormat
-		} else {
-			format = formatter.TableFormatKey
-		}
-	}
-
-	servicesCtx := formatter.Context{
-		Output: dockerCli.Out(),
-		Format: service.NewListFormat(format, opts.Quiet),
-	}
-	return service.ListFormatWrite(servicesCtx, services, info)
+	return services, info, nil
 }
 
 func filterServicesByName(services []swarm.Service, names []string, stackName string) []swarm.Service {

cli/command/stack/services.go

@@ -1,12 +1,17 @@
 package stack
 
 import (
+	"fmt"
+
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
+	"github.com/docker/cli/cli/command/service"
+	"github.com/docker/cli/cli/command/stack/formatter"
 	"github.com/docker/cli/cli/command/stack/kubernetes"
 	"github.com/docker/cli/cli/command/stack/options"
 	"github.com/docker/cli/cli/command/stack/swarm"
 	cliopts "github.com/docker/cli/opts"
+	swarmtypes "github.com/docker/docker/api/types/swarm"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 )
@@ -36,7 +41,48 @@ func newServicesCommand(dockerCli command.Cli, common *commonOptions) *cobra.Com
 
 // RunServices performs a stack services against the specified orchestrator
 func RunServices(dockerCli command.Cli, flags *pflag.FlagSet, commonOrchestrator command.Orchestrator, opts options.Services) error {
-	return runOrchestratedCommand(dockerCli, flags, commonOrchestrator,
-		func() error { return swarm.RunServices(dockerCli, opts) },
-		func(kli *kubernetes.KubeCli) error { return kubernetes.RunServices(kli, opts) })
+	services, info, err := GetServices(dockerCli, flags, commonOrchestrator, opts)
+	if err != nil {
+		return err
+	}
+	return formatWrite(dockerCli, services, opts, info)
+}
+
+// GetServices returns the services for the specified orchestrator
+func GetServices(dockerCli command.Cli, flags *pflag.FlagSet, commonOrchestrator command.Orchestrator, opts options.Services) ([]swarm.Service, map[string]service.ListInfo, error) {
+	switch {
+	case commonOrchestrator.HasAll():
+		return nil, nil, errUnsupportedAllOrchestrator
+	case commonOrchestrator.HasKubernetes():
+		kli, err := kubernetes.WrapCli(dockerCli, kubernetes.NewOptions(flags, commonOrchestrator))
+		if err != nil {
+			return nil, nil, err
+		}
+		return kubernetes.GetServices(kli, opts)
+	default:
+		return swarm.GetServices(dockerCli, opts)
+	}
+}
+
+func formatWrite(dockerCli command.Cli, services []swarmtypes.Service, opts options.Services, info map[string]service.ListInfo) error {
+	// if no services in the stack, print message and exit 0
+	if len(services) == 0 {
+		fmt.Fprintf(dockerCli.Err(), "Nothing found in stack: %s\n", opts.Namespace)
+		return nil
+	}
+
+	format := opts.Format
+	if len(format) == 0 {
+		if len(dockerCli.ConfigFile().ServicesFormat) > 0 && !opts.Quiet {
+			format = dockerCli.ConfigFile().ServicesFormat
+		} else {
+			format = formatter.TableFormatKey
+		}
+	}
+
+	servicesCtx := formatter.Context{
+		Output: dockerCli.Out(),
+		Format: service.NewListFormat(format, opts.Quiet),
+	}
+	return service.ListFormatWrite(servicesCtx, services, info)
 }

cli/command/stack/swarm/services.go

@@ -2,38 +2,35 @@ package swarm
 
 import (
 	"context"
-	"fmt"
 	"sort"
 
 	"github.com/docker/cli/cli/command"
 	"github.com/docker/cli/cli/command/service"
-	"github.com/docker/cli/cli/command/stack/formatter"
 	"github.com/docker/cli/cli/command/stack/options"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/filters"
+	"github.com/docker/docker/api/types/swarm"
 	"vbom.ml/util/sortorder"
 )
 
-// RunServices is the swarm implementation of docker stack services
-func RunServices(dockerCli command.Cli, opts options.Services) error {
+// GetServices is the swarm implementation of listing stack services
+func GetServices(dockerCli command.Cli, opts options.Services) ([]swarm.Service, map[string]service.ListInfo, error) {
 	ctx := context.Background()
 	client := dockerCli.Client()
 
 	filter := getStackFilterFromOpt(opts.Namespace, opts.Filter)
 	services, err := client.ServiceList(ctx, types.ServiceListOptions{Filters: filter})
 	if err != nil {
-		return err
+		return nil, nil, err
 	}
-
-	// if no services in this stack, print message and exit 0
 	if len(services) == 0 {
-		fmt.Fprintf(dockerCli.Err(), "Nothing found in stack: %s\n", opts.Namespace)
-		return nil
+		return []swarm.Service{}, nil, nil
 	}
 
 	sort.Slice(services, func(i, j int) bool {
 		return sortorder.NaturalLess(services[i].Spec.Name, services[j].Spec.Name)
 	})
+
 	info := map[string]service.ListInfo{}
 	if !opts.Quiet {
 		taskFilter := filters.NewArgs()
@@ -43,29 +40,15 @@ func RunServices(dockerCli command.Cli, opts options.Services) error {
 
 		tasks, err := client.TaskList(ctx, types.TaskListOptions{Filters: taskFilter})
 		if err != nil {
-			return err
+			return nil, nil, err
 		}
 
 		nodes, err := client.NodeList(ctx, types.NodeListOptions{})
 		if err != nil {
-			return err
+			return nil, nil, err
 		}
 
 		info = service.GetServicesStatus(services, nodes, tasks)
 	}
-
-	format := opts.Format
-	if len(format) == 0 {
-		if len(dockerCli.ConfigFile().ServicesFormat) > 0 && !opts.Quiet {
-			format = dockerCli.ConfigFile().ServicesFormat
-		} else {
-			format = formatter.TableFormatKey
-		}
-	}
-
-	servicesCtx := formatter.Context{
-		Output: dockerCli.Out(),
-		Format: service.NewListFormat(format, opts.Quiet),
-	}
-	return service.ListFormatWrite(servicesCtx, services, info)
+	return services, info, nil
 }