Adding docker swarm service support. (#12)

README.md

@@ -107,10 +107,11 @@ The full list of labels are:
 
 ## Environment Variables
 
-| Key                 | Description                       | Default                      |
-|---------------------|-----------------------------------|------------------------------|
-| `LOG_LEVEL`         | The level of log verbosity        | `Info`                       |
-| `HOMER_BASE_CONFIG` | Where the base config is located  | `/base.yml`                  |
-| `HOMER_CONFIG`      | Where the Homer config is located | `/config.yml`                |
-| `SERVICE_DISCOVERY` | Either `Docker` or `Consul`       | `Docker`                     |
-| `CONSUL_HOST`       | Host for Consul connnection       | `127.0.0.1:8500`             |
+| Key                 | Description                                   | Default                      |
+|---------------------|-----------------------------------------------|------------------------------|
+| `LOG_LEVEL`         | The level of log verbosity                    | `Info`                       |
+| `HOMER_BASE_CONFIG` | Where the base config is located              | `/base.yml`                  |
+| `HOMER_CONFIG`      | Where the Homer config is located             | `/config.yml`                |
+| `SERVICE_DISCOVERY` | Either `Docker` or `Consul`                   | `Docker`                     |
+| `HOMER_DOCKER_SWARM`| Docker Swarm supprt. Either `true` or `false` | `false`                      |
+| `CONSUL_HOST`       | Host for Consul connnection                   | `127.0.0.1:8500`             |

cmd/main.go

@@ -46,11 +46,15 @@ func main() {
 
 	if conf.ServiceDiscovery == config.Docker {
 		logger.Info("Start watching for container creations and deletions")
-		eventsc, errc := docker.WatchEvents(ctx, conf.Docker)
+		if conf.HomerDockerSwarmMode {
+			logger.Info("Docker Swarm mode enabled")
+			logger.Info("Start watching for service creations, updates, and removal")
+		}
+		eventsc, errc := docker.WatchEvents(ctx, conf.Docker, conf.HomerDockerSwarmMode)
 		for {
 			select {
 			case event := <-eventsc:
-				if event.Action == "start" || event.Action == "die" || strings.HasPrefix(event.Action, "health_status") {
+				if event.Action == "start" || event.Action == "die" || strings.HasPrefix(event.Action, "health_status") || (event.Type == "service" && (event.Action == "create" || event.Action == "update" || event.Action == "remove")) {
 					logger.Trace(fmt.Sprintf("%+v", event))
 					logger.Debug("A " + event.Action + " event occurred")
 					logger.Info(fmt.Sprintf("Event '%s' received from %s. Generating Homer config...", event.Action, event.Actor.Attributes["name"]))
@@ -103,6 +107,21 @@ func generateConfig(ctx context.Context, conf config.Config) error {
 			logger.Debug(fmt.Sprintf("Inspected container %s", parsedContainer.Name))
 			parsedEntry = append(parsedEntry, parsedContainer)
 		}
+
+		if conf.HomerDockerSwarmMode {
+			logger.Debug("Getting Docker services")
+			services, err := docker.ListRunningServices(ctx, conf.Docker)
+			if err != nil {
+				logger.Fatal("Failed to list swarm services for Docker", err)
+			}
+			for _, service := range services {
+				parsedService, err := docker.ParseService(ctx, conf.Docker, service)
+				if err != nil {
+					logger.Error(fmt.Sprintf("Failed to inspect service %s", service.Spec.Name), err)
+				}
+				parsedEntry = append(parsedEntry, parsedService)
+			}
+		}
 	} else if conf.ServiceDiscovery == config.Consul {
 		logger.Debug("Getting Consul service")
 		services := consul.ListServices(conf.Consul)

internal/config/main.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"fmt"
+
 	"github.com/calvinbui/homer-docker-service-discovery/internal/consul"
 	"github.com/calvinbui/homer-docker-service-discovery/internal/docker"
 	"github.com/calvinbui/homer-docker-service-discovery/internal/logger"
@@ -30,6 +31,8 @@ type Config struct {
 	HomerBaseConfigPath string `env:"HOMER_BASE_CONFIG" envDefault:"/base.yml"`
 
 	HomerConfigPath string `env:"HOMER_CONFIG" envDefault:"/config.yml"`
+
+	HomerDockerSwarmMode bool `env:"HOMER_DOCKER_SWARM" envDefault:"false"`
 }
 
 func New() (Config, error) {

internal/docker/events.go

@@ -9,9 +9,13 @@ import (
 	"github.com/docker/docker/client"
 )
 
-func WatchEvents(ctx context.Context, docker client.APIClient) (<-chan events.Message, <-chan error) {
+func WatchEvents(ctx context.Context, docker client.APIClient, swarmMode bool) (<-chan events.Message, <-chan error) {
 	f := filters.NewArgs()
 	f.Add("type", "container")
 
+	if swarmMode {
+		f.Add("type", "service")
+	}
+
 	return docker.Events(ctx, types.EventsOptions{Filters: f})
 }

internal/docker/services.go

@@ -0,0 +1,42 @@
+package docker
+
+import (
+	"context"
+
+	"github.com/calvinbui/homer-docker-service-discovery/internal/entry"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/swarm"
+	"github.com/docker/docker/client"
+)
+
+func ListRunningServices(ctx context.Context, docker client.APIClient) ([]swarm.Service, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	services, err := docker.ServiceList(ctx, types.ServiceListOptions{Status: true})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return services, nil
+}
+
+func ParseService(ctx context.Context, docker client.APIClient, service swarm.Service) (entry.RawEntry, error) {
+	i, _, err := docker.ServiceInspectWithRaw(ctx, service.ID, types.ServiceInspectOptions{})
+
+	if err != nil {
+		return entry.RawEntry{}, err
+	}
+
+	s := entry.RawEntry{
+		Name: i.Spec.Annotations.Name,
+	}
+
+	if i.Spec.Labels != nil {
+		s.Labels = i.Spec.Annotations.Labels
+	}
+
+	return s, nil
+}