refactor: make event filter configurable

Author: buchdag

README.md

@@ -91,6 +91,11 @@ Options:
       config files with template directives. Config files will be merged if this option is specified multiple times. (default [])
   -endpoint string
       docker api endpoint (tcp|unix://..). Default unix:///var/run/docker.sock
+  -event-filter value
+      additional filter for event watched by docker-gen (e.g -event-filter event=connect -event-filter event=disconnect).
+      You can pass this option multiple times to combine filters.
+      By default docker-gen listen for container events start, stop, die and health_status.
+      https://docs.docker.com/engine/reference/commandline/events/#filtering-events
   -interval int
       notify command interval (secs)
   -keep-blank-lines

cmd/docker-gen/main.go

@@ -36,6 +36,7 @@ var (
 	includeStopped        bool
 	configFiles           stringslice
 	configs               config.ConfigFile
+	eventFilter           mapstringslice = mapstringslice{"event": {"start", "stop", "die", "health_status"}}
 	interval              int
 	keepBlankLines        bool
 	endpoint              string
@@ -129,6 +130,9 @@ func initFlags() {
 	flag.StringVar(&tlsCaCert, "tlscacert", filepath.Join(certPath, "ca.pem"), "path to TLS CA certificate file")
 	flag.BoolVar(&tlsVerify, "tlsverify", os.Getenv("DOCKER_TLS_VERIFY") != "", "verify docker daemon's TLS certicate")
 
+	flag.Var(&eventFilter, "event-filter",
+		"additional filter for event watched by docker-gen (e.g -event-filter event=connect -event-filter event=disconnect). You can pass this option multiple times to combine filters. By default docker-gen listen for container events start, stop, die and health_status. https://docs.docker.com/engine/reference/commandline/events/#filtering-events")
+
 	flag.Usage = usage
 	flag.Parse()
 }
@@ -202,13 +206,14 @@ func main() {
 	}
 
 	generator, err := generator.NewGenerator(generator.GeneratorConfig{
-		Endpoint:   endpoint,
-		TLSKey:     tlsKey,
-		TLSCert:    tlsCert,
-		TLSCACert:  tlsCaCert,
-		TLSVerify:  tlsVerify,
-		All:        all,
-		ConfigFile: configs,
+		Endpoint:    endpoint,
+		TLSKey:      tlsKey,
+		TLSCert:     tlsCert,
+		TLSCACert:   tlsCaCert,
+		TLSVerify:   tlsVerify,
+		All:         all,
+		EventFilter: eventFilter,
+		ConfigFile:  configs,
 	})
 
 	if err != nil {

internal/generator/generator.go

@@ -26,6 +26,7 @@ type generator struct {
 	TLSVerify                  bool
 	TLSCert, TLSCaCert, TLSKey string
 	All                        bool
+	EventFilter                map[string][]string
 
 	wg    sync.WaitGroup
 	retry bool
@@ -40,6 +41,8 @@ type GeneratorConfig struct {
 	TLSVerify bool
 	All       bool
 
+	EventFilter map[string][]string
+
 	ConfigFile config.ConfigFile
 }
 
@@ -63,15 +66,16 @@ func NewGenerator(gc GeneratorConfig) (*generator, error) {
 	context.SetDockerEnv(apiVersion)
 
 	return &generator{
-		Client:    client,
-		Endpoint:  gc.Endpoint,
-		TLSVerify: gc.TLSVerify,
-		TLSCert:   gc.TLSCert,
-		TLSCaCert: gc.TLSCACert,
-		TLSKey:    gc.TLSKey,
-		All:       gc.All,
-		Configs:   gc.ConfigFile,
-		retry:     true,
+		Client:      client,
+		Endpoint:    gc.Endpoint,
+		TLSVerify:   gc.TLSVerify,
+		TLSCert:     gc.TLSCert,
+		TLSCaCert:   gc.TLSCACert,
+		TLSKey:      gc.TLSKey,
+		All:         gc.All,
+		EventFilter: gc.EventFilter,
+		Configs:     gc.ConfigFile,
+		retry:       true,
 	}, nil
 }
 
@@ -250,10 +254,7 @@ func (g *generator) generateFromEvents() {
 				}
 				if !watching {
 					options := docker.EventsOptions{
-						Filters: map[string][]string{
-							"event": {"start", "stop", "die", "health_status", "connect", "disconnect"},
-							"type":  {"container", "network"},
-						},
+						Filters: g.EventFilter,
 					}
 
 					err := client.AddEventListenerWithOptions(options, eventChan)