Adapt client to fetch some config parameters from the backend

client.go

@@ -51,11 +51,20 @@ type (
 		OK bool `json:"ok"`
 	}
 
+	rabbitMQConfig struct {
+		ExchangeName string `json:"exchange"`
+		Vhost        string `json:"vhost"`
+	}
+
+	FetchedConfig struct {
+		RabbitMQConfig rabbitMQConfig `json:"rabbitmq_config"`
+		Services       []service      `json:"services"`
+	}
+
 	config struct {
 		Host                   string    `json:"host"`
 		Username               string    `json:"username"`
-		ExchangeName           string    `json:"exchangeName"`
-		Token                  string    `json:"token"`
+		Password               string    `json:"password"`
 		Services               []service `json:"services"`
 		FetchIntervalString    string    `json:"fetch_interval"`    // string parsed by time.ParseDuration
 		ReconnectTimeoutString string    `json:"reconnect_timeout"` // string parsed by time.ParseDuration
@@ -63,6 +72,9 @@ type (
 		DoneTasks              chan task
 		FetchInterval          time.Duration
 		ReconnectTimeout       time.Duration
+
+		ExchangeName string // fetched from backend
+		Vhost        string // fetched  from backend
 	}
 
 	consumer struct {
@@ -126,13 +138,13 @@ serviceLoop:
 	return
 }
 
-func (c *config) fetchConfiguredServices() (services []service, err error) {
+func (c *config) fetchConfig() (err error) {
 	req, err := http.NewRequest("GET", "https://"+c.Host+"/backend/clientapi/config", nil)
 	if err != nil {
 		return
 	}
 
-	req.Header.Add("Authorization", fmt.Sprintf("Token %s", c.Token))
+	req.SetBasicAuth(c.Username, c.Password)
 	resp, err := client.Do(req)
 	if err != nil {
 		return
@@ -143,14 +155,32 @@ func (c *config) fetchConfiguredServices() (services []service, err error) {
 	if err != nil {
 		return
 	}
-	err = json.Unmarshal(body, &services)
+	var fetchedConfig FetchedConfig
+	err = json.Unmarshal(body, &fetchedConfig)
 	if err != nil {
+		log.Fatalf("Unable to parse: %s %s", err, body)
 		return
 	}
+
+	c.ExchangeName = fetchedConfig.RabbitMQConfig.ExchangeName
+	c.Vhost = fetchedConfig.RabbitMQConfig.Vhost
+
+	permittedServices := fetchedConfig.Services
+	log.Printf("[Conf] Permitted services: %s", permittedServices)
+
+	if len(c.Services) == 0 {
+		log.Printf("[Conf] Config specifies no services. Using all permitted services")
+		c.Services = permittedServices
+	} else {
+		// if the config specifies services we check if they are all permitted
+		c.Services = filterPermitted(permittedServices, c.Services)
+	}
+	log.Printf("[Conf] Services: %s", c.Services)
+
 	return
 }
 
-func readConfig(configFile string) (c config, err error) {
+func getConfig(configFile string) (c config, err error) {
 
 	log.Printf("[Conf] Reading config file %s", configFile)
 
@@ -165,21 +195,10 @@ func readConfig(configFile string) (c config, err error) {
 		return
 	}
 
-	var permittedServices []service
-	if permittedServices, err = c.fetchConfiguredServices(); err != nil {
-		log.Printf("[Conf] Error fetching configured services: %s", err)
-	}
-	log.Printf("[Conf] Permitted services: %s", permittedServices)
-
-	if len(c.Services) == 0 {
-		log.Printf("[Conf] Config specifies no services. Using all permitted services")
-		c.Services = permittedServices
-	} else {
-		// if the config specifies services we check if they are all permitted
-		c.Services = filterPermitted(permittedServices, c.Services)
+	if err = c.fetchConfig(); err != nil {
+		log.Printf("[Conf] Error fetching remote config: %s", err)
+		return
 	}
-	log.Printf("[Conf] Services: %s", c.Services)
-
 	if c.FetchInterval, err = time.ParseDuration(c.FetchIntervalString); err != nil {
 		log.Printf("[Conf] Error parsing fetch interval: %s", err)
 		return
@@ -314,6 +333,10 @@ func (c *consumer) reconnect() {
 
 func (c *consumer) startConsuming() (err error) {
 	deliveries, err := c.connect()
+	if err != nil {
+		log.Fatalf("[Conn] Error connecting: %s", err)
+		return
+	}
 
 	// start the first consumer
 	go c.consumer(deliveries)
@@ -328,7 +351,7 @@ func (c *config) consumer() (cons *consumer) {
 		keys = append(keys, fmt.Sprintf("service.%s", serviceName))
 	}
 	cons = &consumer{
-		uri:              fmt.Sprintf("amqps://%s:%s@%s", c.Username, c.Token, c.Host),
+		uri:              fmt.Sprintf("amqps://%s:%s@%s", c.Username, c.Password, c.Host),
 		exchange:         c.ExchangeName,
 		exchangeType:     "topic",
 		bindingKeys:      keys,
@@ -392,7 +415,7 @@ func (c *config) ackTask(ti task) (ok bool, err error) {
 		return
 	}
 
-	req.Header.Add("Authorization", fmt.Sprintf("Token %s", c.Token))
+	req.SetBasicAuth(c.Username, c.Password)
 	resp, err := client.Do(req)
 	if err != nil {
 		return
@@ -449,7 +472,7 @@ func (c *config) fetchTasks() (err error) {
 	}
 	req.URL.RawQuery = q.Encode()
 
-	req.Header.Add("Authorization", fmt.Sprintf("Token %s", c.Token))
+	req.SetBasicAuth(c.Username, c.Password)
 
 	// execute the request
 	resp, err := client.Do(req)
@@ -506,7 +529,7 @@ func main() {
 	kingpin.MustParse(app.Parse(os.Args[1:]))
 
 	// read the config file
-	c, err := readConfig(*configFile)
+	c, err := getConfig(*configFile)
 	if err != nil {
 		log.Fatalf("[Err] No valid config. Exiting")
 	}