Discovery Nats automate

tools/api.go

@@ -34,8 +34,7 @@ func (s State) String() string {
 		"some things boils in here, i'm probably a teapot", "dead"}[s]
 }
 
-type API struct {
-}
+type API struct{}
 
 func (a *API) GetState() (State, int, error) {
 	// Check if the database is up

tools/nats_caller.go

@@ -2,8 +2,11 @@ package tools
 
 import (
 	"encoding/json"
+	"errors"
 	"strings"
+	"sync"
 
+	"cloud.o-forge.io/core/oc-lib/logs"
 	"github.com/nats-io/nats.go"
 )
 
@@ -12,6 +15,7 @@ type NATSMethod int
 const (
 	REMOVE NATSMethod = iota
 	CREATE
+	DISCOVERY
 )
 
 func NameToMethod(name string) NATSMethod {
@@ -56,3 +60,45 @@ func (o *natsCaller) SetNATSPub(dataName string, method NATSMethod, data interfa
 	}
 	return ""
 }
+
+type NATSObjectInterface interface {
+	Serialize() map[string]interface{}
+}
+
+func (o *natsCaller) DiscoveryNATS(name string, model NATSObjectInterface) error {
+	if GetConfig().NATSUrl == "" {
+		return errors.New("NATS_SERVER is not set")
+	}
+	nc, err := nats.Connect(GetConfig().NATSUrl)
+	if err != nil {
+		return errors.New("Could not connect to NATS")
+	}
+	defer nc.Close()
+	wg := &sync.WaitGroup{}
+	wg.Add(2)
+	go o.listenForChange(nc, model, DISCOVERY.GenerateKey("ask"), wg)
+	go o.listenForChange(nc, model, DISCOVERY.GenerateKey(name), wg)
+	wg.Wait()
+	return nil
+}
+
+func (o *natsCaller) listenForChange(nc *nats.Conn, model NATSObjectInterface, chanName string, wg *sync.WaitGroup) {
+	defer wg.Done()
+	api := API{}
+	logger := logs.GetLogger()
+	ch := make(chan *nats.Msg, 64)
+	subs, err := nc.ChanSubscribe(chanName, ch)
+	if err != nil {
+		logger.Error().Msg("Error listening to NATS : " + err.Error())
+		return
+	}
+	defer subs.Unsubscribe()
+
+	for msg := range ch {
+		logger.Info().Msg("Received message from NATS : " + string(msg.Data))
+		m := model.Serialize()
+		s, _, _ := api.GetState()
+		m["state"] = s
+		o.SetNATSPub("answer", DISCOVERY, m)
+	}
+}