feat: callbacks

cmd/traefik/traefik.go

@@ -49,6 +49,7 @@ import (
 	"github.com/traefik/traefik/v3/pkg/tracing"
 	"github.com/traefik/traefik/v3/pkg/types"
 	"github.com/traefik/traefik/v3/pkg/version"
+	"github.com/traefik/traefik/v3/pkg/updater"
 )
 
 func main() {
@@ -197,6 +198,8 @@ func setupServer(staticConfiguration *static.Configuration) (*server.Server, err
 
 	tsProviders := initTailscaleProviders(staticConfiguration, providerAggregator)
 
+	updaterProvider := updater.New(staticConfiguration);
+
 	// Observability
 
 	metricRegistries := registerMetricClients(staticConfiguration.Metrics)
@@ -386,6 +389,9 @@ func setupServer(staticConfiguration *static.Configuration) (*server.Server, err
 		}
 	})
 
+	// Updater
+	watcher.AddListener(updaterProvider.HandleConfigUpdate)
+
 	return server.NewServer(routinesPool, serverEntryPointsTCP, serverEntryPointsUDP, watcher, observabilityMgr), nil
 }
 

docs/content/reference/static-configuration/cli-ref.md

@@ -369,6 +369,9 @@ Periodically check if a new version has been released. (Default: ```true```)
 `--global.sendanonymoususage`:  
 Periodically send anonymous usage statistics. If the option is not specified, it will be disabled by default. (Default: ```false```)
 
+`--global.updatercallbacks`:  
+Callback urls for updater script (example: https://localhost:8080/callback)
+
 `--hostresolver`:  
 Enable CNAME Flattening. (Default: ```false```)
 

docs/content/reference/static-configuration/env-ref.md

@@ -369,6 +369,9 @@ Periodically check if a new version has been released. (Default: ```true```)
 `TRAEFIK_GLOBAL_SENDANONYMOUSUSAGE`:  
 Periodically send anonymous usage statistics. If the option is not specified, it will be disabled by default. (Default: ```false```)
 
+`TRAEFIK_GLOBAL_UPDATERCALLBACKS`:  
+Callback urls for updater script (example: https://localhost:8080/callback)
+
 `TRAEFIK_HOSTRESOLVER`:  
 Enable CNAME Flattening. (Default: ```false```)
 

docs/content/reference/static-configuration/file.toml

@@ -3,6 +3,7 @@
 [global]
   checkNewVersion = true
   sendAnonymousUsage = true
+  updaterCallbacks = ["foobar", "foobar"]
 
 [serversTransport]
   insecureSkipVerify = true

docs/content/reference/static-configuration/file.yaml

@@ -3,6 +3,9 @@
 global:
   checkNewVersion: true
   sendAnonymousUsage: true
+  updaterCallbacks:
+    - foobar
+    - foobar
 serversTransport:
   insecureSkipVerify: true
   rootCAs:

pkg/config/static/static_config.go

@@ -108,6 +108,7 @@ type CertificateResolver struct {
 type Global struct {
 	CheckNewVersion    bool `description:"Periodically check if a new version has been released." json:"checkNewVersion,omitempty" toml:"checkNewVersion,omitempty" yaml:"checkNewVersion,omitempty" label:"allowEmpty" file:"allowEmpty" export:"true"`
 	SendAnonymousUsage bool `description:"Periodically send anonymous usage statistics. If the option is not specified, it will be disabled by default." json:"sendAnonymousUsage,omitempty" toml:"sendAnonymousUsage,omitempty" yaml:"sendAnonymousUsage,omitempty" label:"allowEmpty" file:"allowEmpty" export:"true"`
+	UpdaterCallbacks   []string `description:"Callback urls for updater script (example: https://localhost:8080/callback)" json:"updaterCallbacks,omitempty" toml:"updaterCallbacks,omitempty" yaml:"updaterCallbacks,omitempty" label:"allowEmpty" file:"allowEmpty" export:"true"`
 }
 
 // ServersTransport options to configure communication between Traefik and the servers.

pkg/updater/provider.go

@@ -0,0 +1,49 @@
+package updater
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+
+	"github.com/rs/zerolog/log"
+	"github.com/traefik/traefik/v3/pkg/config/dynamic"
+	"github.com/traefik/traefik/v3/pkg/config/static"
+	"github.com/traefik/traefik/v3/pkg/safe"
+)
+
+type Updater struct {
+	callbackUrls []string
+}
+
+func New(config *static.Configuration) *Updater {
+	updater := &Updater{
+		callbackUrls: config.Global.UpdaterCallbacks,
+	}
+
+	return updater
+}
+
+func (u *Updater) HandleConfigUpdate(cfg dynamic.Configuration) {
+	body, err := json.Marshal(cfg)
+
+	if err != nil {
+		// should never happen?
+		log.Error().Err(err).Msg("Error while marshalling dynamic configuration data to json")
+		return
+	}
+
+	requestBody := bytes.NewBuffer(body)
+
+	for _, url := range u.callbackUrls {
+		safe.Go(func() {
+			resp, err := http.Post(url, "application/json", requestBody)
+
+			if err != nil {
+				log.Error().Err(err).Str("url", url).Msg("Error while sending configuration data to callback")
+			} else  {
+				log.Debug().Str("url", url).Msg("Configuration data sent")
+				resp.Body.Close()
+			}
+		})
+	}
+}