shipper: don't lie about webhook's identity

The webhook was getting a client that had rolloutblocks controller as
its user agent. Even though rollout blocks were indeed what the client
was being used for, that's not guaranteed to stay true forever. So let's
make sure we give the webhook a client tied to its own identity.

Author: juliogreff

cmd/shipper/main.go

@@ -518,7 +518,7 @@ func startWebhook(cfg *cfg) (bool, error) {
 		cfg.webhookBindPort,
 		cfg.webhookKeyPath,
 		cfg.webhookCertPath,
-		client.NewShipperClientOrDie(cfg.restCfg, rolloutblock.AgentName, cfg.restTimeout),
+		client.NewShipperClientOrDie(cfg.restCfg, webhook.AgentName, cfg.restTimeout),
 		cfg.shipperInformerFactory)
 
 	cfg.wg.Add(1)

pkg/webhook/webhook.go

@@ -24,6 +24,10 @@ import (
 	"github.com/bookingcom/shipper/pkg/util/rolloutblock"
 )
 
+const (
+	AgentName = "webhook"
+)
+
 type Webhook struct {
 	shipperClientset    clientset.Interface
 	rolloutBlocksLister listers.RolloutBlockLister