add httserver demo for test and add config.yaml

Author: helight

http-filter-example/README.md

@@ -48,12 +48,40 @@ http_filters:
 - name: sample          # before envoy.router because order matters!
   typed_config:
     "@type": type.googleapis.com/sample.Decoder
-    key: via
+    key: Via
     val: sample-filter
 - name: envoy.router
   typed_config: {}
 ```
- 
+or you can just use this demo yaml file [config.yaml](config.yaml).
+- Run envoy with this cmd：
+```sh
+./bazel-bin/envoy --config-path ./http-filter-example/config.yaml -l trace
+```
+- Run an http server
+```sh
+python httpserver.py
+```
+- Access the http server with curl cmd:
+```sh
+curl http://127.0.0.1:8080
+```
+You can find there is an kv string in the request header to the http server,
+and the key value `Via` has become to `via`, you can see the request header 
+in the http server stdout.
+```sh
+$ python httpserver.py 
+Started httpserver on port  8081
+127.0.0.1 - - [29/Sep/2020 11:30:03] "GET / HTTP/1.1" 200 -
+host: 127.0.0.1:8080
+user-agent: curl/7.58.0
+accept: */*
+x-forwarded-proto: http
+x-request-id: b7a8d227-77a0-4985-a121-5e0f70bd16f2
+via: sample-filter
+x-envoy-expected-rq-timeout-ms: 15000
+content-length: 0
+```
 
 [StreamDecoderFilter]: https://github.com/envoyproxy/envoy/blob/b2610c84aeb1f75c804d67effcb40592d790e0f1/include/envoy/http/filter.h#L300
 [StreamEncoderFilter]: https://github.com/envoyproxy/envoy/blob/b2610c84aeb1f75c804d67effcb40592d790e0f1/include/envoy/http/filter.h#L413

http-filter-example/config.yaml

@@ -0,0 +1,51 @@
+admin:
+  access_log_path: /dev/null
+  address:
+    socket_address:
+      address: 127.0.0.1
+      port_value: 0
+static_resources:
+  clusters:
+    name: cluster_0
+    connect_timeout: 0.25s
+    load_assignment:
+      cluster_name: cluster_0
+      endpoints:
+      - lb_endpoints:
+        - endpoint:
+            address:
+              socket_address:
+                address: 127.0.0.1
+                port_value: 8081
+  listeners:
+  - name: listener_0
+    address:
+      socket_address:
+        address: 127.0.0.1
+        port_value: 8080
+    filter_chains:
+    - filters:
+      - name: envoy.http_connection_manager
+        typed_config:
+          "@type": type.googleapis.com/envoy.config.filter.network.http_connection_manager.v2.HttpConnectionManager
+          stat_prefix: ingress_http
+          codec_type: auto
+          route_config:
+            name: local_route
+            virtual_hosts:
+            - name: local_service
+              domains:
+              - "*"
+              routes:
+              - match:
+                  prefix: "/"
+                route:
+                  cluster: cluster_0
+          http_filters:
+          - name: sample          # before envoy.router because order matters!
+            typed_config:
+              "@type": type.googleapis.com/sample.Decoder
+              key: vIa
+              val: sample-filter
+          - name: envoy.router
+            typed_config: {}

http-filter-example/httpserver.py

@@ -0,0 +1,27 @@
+#!/usr/bin/python
+from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer
+
+PORT = 8081
+
+class doHandler(BaseHTTPRequestHandler):
+    # Handler for the GET requests
+    def do_GET(self):
+        self.send_response(200)
+        self.send_header('Content-type','text/html')
+        self.end_headers()
+        print self.headers  # print the http header
+        # Send the html message
+        self.wfile.write("Hello World !")
+        return
+
+try:
+    # Create a web server and define the handler to manage the incoming request
+    server = HTTPServer(('', PORT), doHandler)
+    print 'Started httpserver on port ' , PORT
+
+    # Wait forever for incoming http requests
+    server.serve_forever()
+
+except KeyboardInterrupt:
+    print 'shutting down the web server'
+    server.socket.close()