define const for labels

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

local/compose.go

@@ -165,7 +165,7 @@ func toProgressEvent(jm jsonmessage.JSONMessage, w progress.Writer) {
 func (s *local) Down(ctx context.Context, projectName string) error {
 	list, err := s.containerService.apiClient.ContainerList(ctx, moby.ContainerListOptions{
 		Filters: filters.NewArgs(
-			filters.Arg("label", "com.docker.compose.project="+projectName),
+			projectFilter(projectName),
 		),
 	})
 	if err != nil {
@@ -212,7 +212,7 @@ func (s *local) Down(ctx context.Context, projectName string) error {
 func (s *local) Logs(ctx context.Context, projectName string, w io.Writer) error {
 	list, err := s.containerService.apiClient.ContainerList(ctx, moby.ContainerListOptions{
 		Filters: filters.NewArgs(
-			filters.Arg("label", "com.docker.compose.project="+projectName),
+			projectFilter(projectName),
 		),
 	})
 	if err != nil {
@@ -221,7 +221,7 @@ func (s *local) Logs(ctx context.Context, projectName string, w io.Writer) error
 	var wg sync.WaitGroup
 	consumer := formatter.NewLogConsumer(w)
 	for _, c := range list {
-		service := c.Labels["com.docker.compose.service"]
+		service := c.Labels[serviceLabel]
 		containerId := c.ID
 		go func() {
 			s.containerService.Logs(ctx,containerId, containers.LogsRequest{
@@ -239,7 +239,7 @@ func (s *local) Logs(ctx context.Context, projectName string, w io.Writer) error
 func (s *local) Ps(ctx context.Context, projectName string) ([]compose.ServiceStatus, error) {
 	list, err := s.containerService.apiClient.ContainerList(ctx, moby.ContainerListOptions{
 		Filters: filters.NewArgs(
-			filters.Arg("label", "com.docker.compose.project="+projectName),
+			projectFilter(projectName),
 		),
 	})
 	if err != nil {
@@ -250,7 +250,7 @@ func (s *local) Ps(ctx context.Context, projectName string) ([]compose.ServiceSt
 		// TODO group by service
 		status = append(status, compose.ServiceStatus{
 			ID:         c.ID,
-			Name:       c.Labels["com.docker.compose.service"],
+			Name:       c.Labels[serviceLabel],
 			Replicas:   0,
 			Desired:    0,
 			Ports:      nil,
@@ -260,6 +260,7 @@ func (s *local) Ps(ctx context.Context, projectName string) ([]compose.ServiceSt
 	return status, nil
 }
 
+
 func (s *local) List(ctx context.Context, projectName string) ([]compose.Stack, error) {
 	_, err := s.containerService.apiClient.ContainerList(ctx, moby.ContainerListOptions{All: true})
 	if err != nil {
@@ -287,10 +288,10 @@ func getContainerCreateOptions(p *types.Project, s types.ServiceConfig, number i
 		return nil, nil, nil, err
 	}
 	labels := map[string]string{
-		"com.docker.compose.project":     p.Name,
-		"com.docker.compose.service":     s.Name,
-		"com.docker.compose.config-hash": hash,
-		"com.docker.compose.container-number": strconv.Itoa(number),
+		projectLabel:     p.Name,
+		serviceLabel:     s.Name,
+		configHashLabel: hash,
+		containerNumberLabel: strconv.Itoa(number),
 	}
 
 	var (

local/convergence.go

@@ -34,8 +34,8 @@ import (
 func (s *local) ensureService(ctx context.Context, project *types.Project, service types.ServiceConfig) error {
 	actual, err := s.containerService.apiClient.ContainerList(ctx, moby.ContainerListOptions{
 		Filters: filters.NewArgs(
-			filters.Arg("label", "com.docker.compose.project="+project.Name),
-			filters.Arg("label", "com.docker.compose.service="+service.Name),
+			filters.Arg("label", fmt.Sprintf("%s=%s", projectLabel, project.Name)),
+			filters.Arg("label", fmt.Sprintf("%s=%s", serviceLabel, service.Name)),
 		),
 	})
 	if err != nil {
@@ -80,7 +80,7 @@ func (s *local) ensureService(ctx context.Context, project *types.Project, servi
 	}
 	for _, container := range actual {
 		container := container
-		diverged := container.Labels["com.docker.compose.config-hash"] != expected
+		diverged := container.Labels[configHashLabel] != expected
 		if diverged {
 			eg.Go(func() error {
 				return s.recreateContainer(ctx, project, service, container)
@@ -103,7 +103,7 @@ func (s *local) ensureService(ctx context.Context, project *types.Project, servi
 func nextContainerNumber(containers []moby.Container) (int, error) {
 	max := 0
 	for _, c := range containers {
-		n, err := strconv.Atoi(c.Labels["com.docker.compose.container-number"])
+		n, err := strconv.Atoi(c.Labels[containerNumberLabel])
 		if err != nil {
 			return 0, err
 		}
@@ -164,7 +164,7 @@ func (s *local) recreateContainer(ctx context.Context, project *types.Project, s
 	if err != nil {
 		return err
 	}
-	number, err := strconv.Atoi(container.Labels["com.docker.compose.container-number"])
+	number, err := strconv.Atoi(container.Labels[containerNumberLabel])
 	if err != nil {
 		return err
 	}

local/labels.go

@@ -0,0 +1,35 @@
+// +build local
+
+/*
+   Copyright 2020 Docker Compose CLI authors
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package local
+
+import (
+	"fmt"
+	"github.com/docker/docker/api/types/filters"
+)
+
+const (
+	projectLabel = "com.docker.compose.project"
+	serviceLabel = "com.docker.compose.service"
+	configHashLabel = "com.docker.compose.config-hash"
+	containerNumberLabel = "com.docker.compose.container-number"
+)
+
+func projectFilter(projectName string) filters.KeyValuePair {
+	return filters.Arg("label", fmt.Sprintf("%s=%s", projectLabel, projectName))
+}