fix gcp-pubsub-gateway (#270)

* Add root certificates in gcp-pubsub Dockerfile.

* Add value of event source id to EventSource.

gateways/community/gcp-pubsub/Dockerfile

@@ -1,3 +1,7 @@
+FROM alpine:3.9 as alpine
+RUN apk add -U --no-cache ca-certificates
+
 FROM scratch
 COPY dist/gcp-pubsub-gateway /bin/
+COPY --from=alpine /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 ENTRYPOINT [ "/bin/gcp-pubsub-gateway" ]

gateways/community/gcp-pubsub/start.go

@@ -17,8 +17,10 @@ limitations under the License.
 package pubsub
 
 import (
-	"cloud.google.com/go/pubsub"
 	"context"
+	"fmt"
+
+	"cloud.google.com/go/pubsub"
 	"github.com/argoproj/argo-events/gateways"
 	"google.golang.org/api/option"
 )
@@ -66,7 +68,7 @@ func (ese *GcpPubSubEventSourceExecutor) listenEvents(ctx context.Context, sc *p
 	}
 
 	logger.Info("subscribing to GCP PubSub topic")
-	sub, err := client.CreateSubscription(ctx, eventSource.Id,
+	sub, err := client.CreateSubscription(ctx, fmt.Sprintf("%v-%v", eventSource.Name, eventSource.Id),
 		pubsub.SubscriptionConfig{Topic: topic})
 	if err != nil {
 		errorCh <- err

gateways/event-sources.go

@@ -153,6 +153,7 @@ func (gc *GatewayConfig) startEventSources(eventSources map[string]*EventSourceC
 			if valid, _ := eventSource.Client.ValidateEventSource(eventSource.Ctx, &EventSource{
 				Data: eventSource.Data.Config,
 				Name: eventSource.Data.Src,
+				Id:   eventSource.Data.ID,
 			}); !valid.IsValid {
 				gc.Log.WithFields(
 					map[string]interface{}{
@@ -185,6 +186,7 @@ func (gc *GatewayConfig) startEventSources(eventSources map[string]*EventSourceC
 			eventStream, err := eventSource.Client.StartEventSource(eventSource.Ctx, &EventSource{
 				Name: eventSource.Data.Src,
 				Data: eventSource.Data.Config,
+				Id:   eventSource.Data.ID,
 			})
 			if err != nil {
 				gc.Log.WithError(err).Error("error occurred while starting event source")