Fetch only configured services

client.go

@@ -88,15 +88,16 @@ func (du deploymentUpdate) String() string {
 }
 
 func filterPermitted(permitted []service, wanted []service) (remainder []service) {
+	serviceLoop:
 	for _, service := range wanted {
 		for _, permittedService := range permitted {
 			if service.Name == permittedService.Name {
 				remainder = append(remainder, service)
-				continue
+				continue serviceLoop
 			}
 		}
 		log.Printf(
-			" [C] Configured service %s is not permitted and therefore skipped",
+			" [C] Skipping unpermitted service %s",
 			service,
 		)
 	}
@@ -112,7 +113,7 @@ func readConfig(configFile string) (c config, err error) {
 	log.Printf(" [C] Permitted services: %s", permittedServices)
 
 	if len(c.Services) == 0 {
-		log.Printf(" [C] Config specifies no services. Using all permitted services.")
+		log.Printf(" [C] Config specifies no services. Using all permitted services")
 		c.Services = permittedServices
 	} else {
 		// if the config specifies services we check if they are all permitted
@@ -143,18 +144,40 @@ func handleInitialUpdates(initialUpdate deploymentUpdates) {
 	}
 }
 
-func (c *config) fetchInitialUpdates() (updates deploymentUpdates) {
-	req, err := http.NewRequest("GET", "https://"+c.Host+"/backend/clientapi/deployments", nil)
-	failOnError(err, "fetching services")
+func (c *config) fetchInitialUpdates() (updates deploymentUpdates, err error) {
+	if len(c.Services) == 0 {
+		log.Printf(" [I] Not fetching initial updates because the are no services to fetch")
+		return
+	}
+
+	// construct a request
+	uri := "https://" + c.Host + "/backend/clientapi/deployments"
+	req, err := http.NewRequest("GET", uri, nil)
+	if err != nil {
+		return
+	}
+
+	// add query params for the services
+	q := req.URL.Query()
+	for _, service := range c.Services {
+		q.Add("s", service.Name)
+	}
+	req.URL.RawQuery = q.Encode()
 
 	req.Header.Add("Authorization", fmt.Sprintf("Token %s", c.Token))
+
+	// execute the request
 	resp, err := client.Do(req)
-	failOnError(err, "fetching initial updates")
+	if err != nil {
+		return
+	}
 	defer resp.Body.Close()
 
 	body, err := ioutil.ReadAll(resp.Body)
 	err = json.Unmarshal(body, &updates)
-	failOnError(err, "decoding initial updates "+string(body))
+	if err != nil {
+		return
+	}
 
 	log.Printf(" [I] Received initial updates:")
 
@@ -177,17 +200,21 @@ func (c *config) fetchConfiguredServices() []service {
 	return services
 }
 
-func (c *config) pubSub() {
+func (c *config) pubSub() (err error) {
 	if len(c.Services) == 0 {
-		log.Printf(" [P] Not starting pubsub because the are no services to subscribe to.")
+		log.Printf(" [P] Not starting pubsub because the are no services to subscribe to")
 		return
 	}
 	conn, err := amqp.Dial(fmt.Sprintf("amqp://%s:%s@%s", c.Username, c.Token, c.Host))
-	failOnError(err, "Failed to connect to RabbitMQ")
+	if err != nil {
+		return
+	}
 	defer conn.Close()
 
 	ch, err := conn.Channel()
-	failOnError(err, "Failed to open a channel")
+	if err != nil {
+		return
+	}
 	defer ch.Close()
 
 	q, err := ch.QueueDeclare(
@@ -198,11 +225,13 @@ func (c *config) pubSub() {
 		false, // no-wait
 		nil,   // arguments
 	)
-	failOnError(err, "Failed to declare a queue")
+	if err != nil {
+		return
+	}
 
 	for _, s := range c.Services {
 		routingKey := "service." + s.Name
-		log.Printf(" [Q] Binding queue to exchange '%s' with routing key '%s'",
+		log.Printf(" [P] Binding queue to exchange '%s' with routing key '%s'",
 			c.ExchangeName, routingKey)
 
 		err = ch.QueueBind(
@@ -211,7 +240,9 @@ func (c *config) pubSub() {
 			c.ExchangeName, // exchange
 			false,
 			nil)
-		failOnError(err, "Failed to bind a queue")
+		if err != nil {
+			return
+		}
 	}
 
 	msgs, err := ch.Consume(
@@ -223,7 +254,9 @@ func (c *config) pubSub() {
 		false,  // no-wait
 		nil,    // args
 	)
-	failOnError(err, "Failed to register a consumer")
+	if err != nil {
+		return
+	}
 
 	forever := make(chan bool)
 
@@ -236,15 +269,19 @@ func (c *config) pubSub() {
 				d.DeliveryTag,
 				false, // ack multiple (since delivery tag)
 			)
-			failOnError(err, "Failed to acknowledge message")
+			if err != nil {
+				return
+			}
 		}
 	}()
 
 	log.Printf(" [*] Waiting for messages. To exit press CTRL+C")
 	<-forever
+	return
 }
 
 func main() {
+	var err error
 	app := kingpin.New("fumClient", "Client for the 'Federated user management in the Helmholtz Data Federation' project")
 
 	configFile := app.Arg("config", "Config file to file to use.").Required().String()
@@ -261,12 +298,15 @@ func main() {
 	failOnError(err, "Reading config file "+*configFile)
 
 	// we first get the changes which happened while we were offline
-	initialUpdates := conf.fetchInitialUpdates()
+	initialUpdates, err := conf.fetchInitialUpdates()
+	failOnError(err, "Fetching initial updates ")
+
 	handleInitialUpdates(initialUpdates)
 
 	if !*oneshot {
 
 		// and then connect to rabbitmq for live updates for these services
-		conf.pubSub()
+		err = conf.pubSub()
+		failOnError(err, "PubSub System")
 	}
 }