implemented enableLabel by a Filter

container/client.go

@@ -5,10 +5,10 @@ import (
 	"io/ioutil"
 	"time"
 
-	log "github.com/sirupsen/logrus"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/network"
 	dockerclient "github.com/docker/docker/client"
+	log "github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
 )
 
@@ -16,10 +16,6 @@ const (
 	defaultStopSignal = "SIGTERM"
 )
 
-// A Filter is a prototype for a function that can be used to filter the
-// results from a call to the ListContainers() method on the Client.
-type Filter func(Container) bool
-
 // A Client is the interface through which watchtower interacts with the
 // Docker API.
 type Client interface {
@@ -37,20 +33,19 @@ type Client interface {
 //  * DOCKER_HOST			the docker-engine host to send api requests to
 //  * DOCKER_TLS_VERIFY		whether to verify tls certificates
 //  * DOCKER_API_VERSION	the minimum docker api version to work with
-func NewClient(pullImages, enableLabel bool) Client {
+func NewClient(pullImages bool) Client {
 	cli, err := dockerclient.NewEnvClient()
 
 	if err != nil {
 		log.Fatalf("Error instantiating Docker client: %s", err)
 	}
 
-	return dockerClient{api: cli, pullImages: pullImages, enableLabel: enableLabel}
+	return dockerClient{api: cli, pullImages: pullImages}
 }
 
 type dockerClient struct {
-	api         *dockerclient.Client
-	pullImages  bool
-	enableLabel bool
+	api        *dockerclient.Client
+	pullImages bool
 }
 
 func (client dockerClient) ListContainers(fn Filter) ([]Container, error) {
@@ -62,6 +57,7 @@ func (client dockerClient) ListContainers(fn Filter) ([]Container, error) {
 	runningContainers, err := client.api.ContainerList(
 		bg,
 		types.ContainerListOptions{})
+
 	if err != nil {
 		return nil, err
 	}
@@ -79,15 +75,6 @@ func (client dockerClient) ListContainers(fn Filter) ([]Container, error) {
 
 		c := Container{containerInfo: &containerInfo, imageInfo: &imageInfo}
 
-		if client.enableLabel {
-			// If label filtering is enabled, containers should only be enabled
-			// if the label is specifically set to true.
-			enabledLabel, ok := c.Enabled()
-			if !ok || !enabledLabel {
-				continue
-			}
-		}
-
 		if fn(c) {
 			cs = append(cs, c)
 		}

container/filters.go

@@ -0,0 +1,61 @@
+package container
+
+// A Filter is a prototype for a function that can be used to filter the
+// results from a call to the ListContainers() method on the Client.
+type Filter func(FilterableContainer) bool
+
+// A FilterableContainer is the interface which is used to filter
+// containers.
+type FilterableContainer interface {
+	Name() string
+	IsWatchtower() bool
+	Enabled() (bool, bool)
+}
+
+// WatchtowerContainersFilter filters only watchtower containers
+func WatchtowerContainersFilter(c FilterableContainer) bool { return c.IsWatchtower() }
+
+// Filter no containers and returns all
+func noFilter(FilterableContainer) bool { return true }
+
+// Filters containers which don't have a specified name
+func filterByNames(names []string, baseFilter Filter) Filter {
+	if len(names) == 0 {
+		return baseFilter
+	}
+
+	return func(c FilterableContainer) bool {
+		for _, name := range names {
+			if (name == c.Name()) || (name == c.Name()[1:]) {
+				return baseFilter(c)
+			}
+		}
+		return false
+	}
+}
+
+// Filters out containers that don't have the 'enableLabel'
+func filterByEnableLabel(baseFilter Filter) Filter {
+	return func(c FilterableContainer) bool {
+		// If label filtering is enabled, containers should only be enabled
+		// if the label is specifically set to true.
+		enabledLabel, ok := c.Enabled()
+		if !ok || !enabledLabel {
+			return false
+		}
+
+		return baseFilter(c)
+	}
+}
+
+// BuildFilter creates the needed filter of containers
+func BuildFilter(names []string, enableLabel bool) Filter {
+	filter := noFilter
+	filter = filterByNames(names, filter)
+	if enableLabel {
+		// If label filtering is enabled, containers should only be considered
+		// if the label is specifically set.
+		filter = filterByEnableLabel(filter)
+	}
+	return filter
+}