From 85d9fbcc8bd540edee0e6eddac6325ba60b28415 Mon Sep 17 00:00:00 2001
From: Lorenzo Venerandi <lollo.venerandi@gmail.com>
Date: Fri, 6 Dec 2024 01:29:36 +0100
Subject: [PATCH] updated messaging handling

---
 README.md    |  5 ++++
 messaging.go | 23 ++++++++-----------
 wadm.yaml    | 64 ++++++++++++++++++++++++++++++++++------------------
 3 files changed, 56 insertions(+), 36 deletions(-)

diff --git a/README.md b/README.md
index 7860f36..53b3653 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,11 @@ This is a simple TinyGo Wasm example that responds with a "Hello World" message
 wash build
 ```
 
+## Push OCI Artifact to Gitea
+```bash
+wash push gitea.rebus.ninja/lore/go-nats-client:1.x.x build/go_nats_client_s.wasm 
+```
+
 ## Running with wasmtime
 
 You must have wasmtime 25.0.0 for this to work. Make sure to follow the build step above first.
diff --git a/messaging.go b/messaging.go
index fdd4765..e9d28b9 100644
--- a/messaging.go
+++ b/messaging.go
@@ -18,23 +18,18 @@ var messagingConsumer = &messagingConsumerAdapter{
 
 func handleMessage(msg types.BrokerMessage) cm.Result[string, struct{}, string] {
 	logger := wasilog.ContextLogger("handleMessage")
-	replyTo := msg.ReplyTo.Some()
 
 	logger.Info("Received message", "subject", msg.Subject)
 
-	if replyTo != nil {
-		logger.Info("Sending reply", "subject", *replyTo)
-
-		reply := types.BrokerMessage{
-			Subject: *replyTo,
-			Body:    msg.Body,
-			ReplyTo: cm.None[string](),
-		}
-		res := messagingConsumer.Publish(reply)
-		if res.IsErr() {
-			logger.Error("Failed to send reply", "error", *res.Err())
-			return res
-		}
+	reply := types.BrokerMessage{
+		Subject: msg.Subject + ".reply",
+		Body:    msg.Body,
+		ReplyTo: cm.None[string](),
+	}
+	res := messagingConsumer.Publish(reply)
+	if res.IsErr() {
+		logger.Error("Failed to send reply", "error", *res.Err())
+		return res
 	}
 
 	return cm.OK[cm.Result[string, struct{}, string]](struct{}{})
diff --git a/wadm.yaml b/wadm.yaml
index 053034f..7c1b8f4 100644
--- a/wadm.yaml
+++ b/wadm.yaml
@@ -10,38 +10,58 @@ metadata:
     wasmcloud.dev/homepage: https://github.com/wasmCloud/wasmCloud/tree/main/examples/golang/components/http-hello-world
     wasmcloud.dev/categories: |
       http,outgoing-http,http-server,tinygo,golang,example
+spec:
 spec:
   components:
-    - name: http-component
+    - name: echo
       type: component
       properties:
-        image: file://./build/http_hello_world_s.wasm
+        # To use the locally compiled code in this folder, use the line below instead after running `wash build`:
+        # image: file://./build/echo_messaging_s.wasm
+        image: gitea.rebus.ninja/lore/go-nats-client:1.0.1
+        id: echo
       traits:
         # Govern the spread/scheduling of the component
         - type: spreadscaler
           properties:
             instances: 1
-
-    # Add a capability provider that enables HTTP access
-    - name: httpserver
-      type: capability
-      properties:
-        image: ghcr.io/wasmcloud/http-server:0.23.2
-      traits:
-        # Link the httpserver to the component, and configure the HTTP server
-        # to listen on port 8000 for incoming requests
-        #
-        # Since the HTTP server calls the `http-component` component, we establish
-        # a unidirectional link from this `httpserver` provider (the "source")
-        # to the `http-component` component (the "target"), so the server can invoke
-        # the component to handle a request.
+        # Establish a unidirectional link to the messaging capability provider (powered by NATS),
+        # so the `echo` component can make use of messaging interface functionality
+        # (i.e. making interacting with the messaging system, in this case NATS)            
         - type: link
           properties:
-            target: http-component
-            namespace: wasi
-            package: http
-            interfaces: [incoming-handler]
+            target: nats
+            namespace: wasmcloud
+            package: messaging
+            interfaces: [consumer]
+
+    # Add a capability provider that implements `wasmcloud:messaging` using NATS
+    - name: nats
+      type: capability
+      properties:
+        image: ghcr.io/wasmcloud/messaging-nats:0.23.1
+        ## To configure OTEL integration for this provider specifically, uncomment the lines below
+        # config:
+        #   - name: otel
+        #     properties:
+        #       otel_exporter_otlp_endpoint: "http://all-in-one:4318"
+        #       otel_exporter_otlp_traces_endpoint: "http://traces-backend/v1/traces"
+        #       otel_exporter_otlp_metrics_endpoint: "http://metrics-backend/v1/metrics"
+        #       otel_exporter_otlp_logs_endpoint: "http://logs-backend/v1/logs"
+      traits:
+        # Since the `nats` capability provider calls an component to handle messages 
+        # coming over subscriptions, this provider needs a unidirectional link to the
+        # component that wil be called.
+        # 
+        # Here we link the `nats` provider (the "source"), to the `echo` component (the "target"),
+        # so that so the provider can deliver messages to the component (by invoking the wasmcloud:messaging/handler interface) .
+        - type: link
+          properties:
+            target: echo
+            namespace: wasmcloud
+            package: messaging
+            interfaces: [handler]
             source_config:
-              - name: default-http
+              - name: simple-subscription
                 properties:
-                  address: 127.0.0.1:8000
+                  subscriptions: wasmcloud.echo