feat(router): implement (method, path) routing

BREAKING CHANGE: http file renamed to server, route to router

.gitignore

@@ -1 +1,2 @@
 *.swp
+**/__pycache__/

README.md

@@ -4,8 +4,10 @@ A [Prometheus](https://prometheus.io/) SDK for CircuitPython/MicroPython boards,
 into existing Prometheus/Grafana monitoring infrastructure.
 
 - only depends on `socket`
-- API-compatible with [prometheus/client_python](https://github.com/prometheus/client_python)
-- basic HTTP server with path routing
+- runs on CircuitPython 4.x for embedded devices
+- runs on CPython 3.x for local testing
+- API compatible with the official [prometheus/client_python](https://github.com/prometheus/client_python)
+- basic HTTP server with path/method routing
 - not terribly slow (`wrk` reports upwards of 100rps with 2 metrics)
 
 ## Contents

examples/feather-m4-express.py

@@ -1,7 +1,8 @@
 # custom
-from prometheus_express.http import start_http_server, await_http_request
 from prometheus_express.metric import Counter, Gauge
 from prometheus_express.registry import CollectorRegistry
+from prometheus_express.router import Router
+from prometheus_express.server import start_http_server, await_http_request
 
 # system
 import board
@@ -62,14 +63,31 @@ def main():
     ready = False
     bound = False
 
-    server = False
-
     registry = CollectorRegistry(namespace='prom_express')
     metric_c = Counter('test_counter',
                        'a test counter', registry=registry)
     metric_g = Gauge('test_gauge',
                      'a test gauge', registry=registry)
 
+    def icon_handler(headers, body):
+        return {
+            'status': '200 OK',
+            'type': 'image/png;base64',
+            'content': 'iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAIAAAD91JpzAAAAFklEQVQI12N8HmPBxMPHxMTDx8TNBwAUNwHSqFS0zAAAAABJRU5ErkJggg==',
+        }
+
+    def prom_handler(headers, body):
+        return {
+            'status': '200 OK',
+            'content': '\r\n'.join(registry.print()),
+        }
+
+    router = Router([
+        ('GET', '/favicon.ico', icon_handler),
+        ('GET', '/metrics', prom_handler),
+    ])
+    server = False
+
     rgb[0] = RED  # starting
     while ready == False:
         ready = check_network()
@@ -83,7 +101,7 @@ def main():
         metric_c.inc(random.randint(0, 50))
         metric_g.set(random.randint(0, 5000))
         try:
-            await_http_request(server, registry)
+            await_http_request(server, router)
         except OSError as err:
             print('Error accepting request: {}'.format(err))
             server, bound = bind()

examples/pc-python-3.py

@@ -1,9 +1,9 @@
 #! /usr/bin/env python3
 
 # custom
-from prometheus_express.http import start_http_server, await_http_request
 from prometheus_express.metric import Counter, Gauge
 from prometheus_express.registry import CollectorRegistry
+from prometheus_express.server import start_http_server, await_http_request
 
 # system
 import socket

prometheus_express/router.py

@@ -0,0 +1,22 @@
+def errorHandler(headers, body):
+    return {
+      'status': 404,
+      'content': 'Not Found',
+    }
+
+
+class Router():
+    routes = []
+
+    def __init__(self, routes=[]):
+        self.routes = routes
+
+    def register(self, method, path, handler):
+        self.routes.add((method, path, handler))
+
+    def select(self, method, path):
+        for r in self.routes:
+            if r[0] == method and r[1] == path:
+                return r[2]
+
+        return errorHandler

prometheus_express/http.py → prometheus_express/server.py

@@ -14,27 +14,29 @@ def start_http_server(port, address='0.0.0.0', extraRoutes={}, metricsRoute='/me
     return http_socket
 
 
-def await_http_request(server_socket, registry):
+def await_http_request(server_socket, router):
     conn, addr = server_socket.accept()
     print('Connection: {}'.format(addr))
 
     req = conn.recv(1024).decode(http_encoding)
     req_headers = parse_headers(req)
     print('Headers: {}'.format(req_headers))
 
-    if req_headers['path'] == registry.path:
-        metrics = registry.print()
-        send_http_response(conn, http_break.join(metrics))
+    handler = router.select(req_headers['method'], req_headers['path'])
+    resp = handler(req_headers, '')
+
+    if 'type' in resp:
+        send_http_response(conn, resp['status'], resp['content'], type=resp['type'])
     else:
-        send_http_response(conn, 'Hello World!')
+        send_http_response(conn, resp['status'], resp['content'])
 
 
-def send_http_response(conn, body):
+def send_http_response(conn, status, body, type='text/plain'):
     content_data = body.encode(http_encoding)
     content_length = len(content_data)
 
     line_break = http_break.encode(http_encoding)
-    headers = print_http_headers(length=content_length)
+    headers = print_http_headers(status=status, type=type, length=content_length)
 
     try:
         for line in headers: