docs(prism-agent): add basic webhook code snippet (#589)

* fix(prism-agent): correctly format bearer token in Authorization header (add 'Bearer' prefix)

* docs(prism-agent): add Python code snippet for basic webhook logging incoming requests

* chore(prism-agent): log events in webhook publisher at 'debug' level

docs/docusaurus/webhooks/webhook.md

@@ -165,6 +165,99 @@ attempt. Please note that the number of retries and the interval duration are cu
 By default, this retry mechanism provides a reasonable level of reliability for delivering webhook notifications,
 allowing for temporary network issues or intermittent failures.
 
+### A basic Webhook implementation for logging requests
+
+In the following example, we will demonstrate a simple Python code snippet that sets up a webhook endpoint and logs
+incoming HTTP requests to the console. This basic implementation can serve as a starting point for building more
+advanced webhook systems.
+
+In the provided Python code snippet, the port on which the webhook listener will listen for incoming requests should be
+passed as a command-line parameter. This allows flexibility in starting multiple webhooks in parallel, which is useful
+when testing multiple locally running agents, e.g. for a holder, an issuer, and/or a verifier.
+
+```python
+#!/usr/bin/env python3
+"""
+Very simple HTTP server in python for logging requests
+Usage::
+    ./server.py [<port>]
+"""
+import logging
+import json
+from http.server import BaseHTTPRequestHandler, HTTPServer
+
+grey = "\x1b[38;20m"
+yellow = "\x1b[33;20m"
+green = "\x1b[32;20m"
+red = "\x1b[31;20m"
+bold_red = "\x1b[31;1m"
+reset = "\x1b[0m"
+
+consoleHandler = logging.StreamHandler()
+formatter = logging.Formatter(f"""%(asctime)s - %(levelname)s - %(name)s
+--------------------------------------- request ---------------------------------------
+{green}%(method)s %(path)s{reset}
+%(headers)s
+{yellow}%(data)s{reset}
+-----------------------------------
+"""
+                              )
+consoleHandler.setFormatter(formatter)
+consoleHandler.setLevel(logging.INFO)
+
+logger = logging.getLogger('http-request')
+logger.setLevel(logging.INFO)
+logger.addHandler(consoleHandler)
+
+class S(BaseHTTPRequestHandler):
+
+    def _set_response(self):
+        self.send_response(200)
+        self.send_header('Content-type', 'text/html')
+        self.end_headers()
+
+    def do_GET(self):
+        logging.info("GET request,\nPath: %s\nHeaders:\n%s\n", str(self.path), str(self.headers))
+        self._set_response()
+        self.wfile.write("GET request for {}".format(self.path).encode('utf-8'))
+
+    def do_POST(self):
+        content_length = int(self.headers['Content-Length'])  # <--- Gets the size of data
+        post_data = self.rfile.read(content_length)  # <--- Gets the data itself
+        json_obj = json.loads(post_data.decode('utf-8'))
+        json_data = json.dumps(json_obj, indent=2)
+        logger.info(msg="Request content", extra={
+            'method': "POST",
+            'path': str(self.path),
+            'headers': str(self.headers),
+            'data': json_data
+        })
+        self._set_response()
+        self.wfile.write("POST request for {}".format(self.path).encode('utf-8'))
+
+    def log_message(self, format, *args):
+        pass
+
+
+def run(server_class=HTTPServer, handler_class=S, port=80):
+    server_address = ('', port)
+    httpd = server_class(server_address, handler_class)
+    try:
+        httpd.serve_forever()
+    except KeyboardInterrupt:
+        pass
+    httpd.server_close()
+
+
+if __name__ == '__main__':
+    from sys import argv
+
+    if len(argv) == 2:
+        run(port=int(argv[1]))
+    else:
+        run()
+```
+
 ## Conclusion
 
 Congratulations! You've learned about webhook notifications in PRISM Agent. By leveraging this feature, you can receive

prism-agent/service/server/src/main/scala/io/iohk/atala/agent/notification/WebhookPublisher.scala

@@ -17,7 +17,7 @@ class WebhookPublisher(appConfig: AppConfig, notificationService: EventNotificat
 
   private val config = appConfig.agent.webhookPublisher
   private val baseHeaders =
-    config.apiKey.map(key => Headers.authorization(key)).getOrElse(Headers.empty) ++
+    config.apiKey.map(key => Headers.bearerAuthorizationHeader(key)).getOrElse(Headers.empty) ++
       Headers.contentType(HeaderValues.applicationJson)
 
   private val parallelism = config.parallelism match {
@@ -68,7 +68,7 @@ class WebhookPublisher(appConfig: AppConfig, notificationService: EventNotificat
       encoder: JsonEncoder[A]
   ): ZIO[Client, UnexpectedError, Unit] = {
     for {
-      _ <- ZIO.log(s"Sending event: $event to HTTP webhook URL: $url.")
+      _ <- ZIO.logDebug(s"Sending event: $event to HTTP webhook URL: $url.")
       response <- Client
         .request(
           url = url.toString,