Add port and host as variables

Author: maggie44

README.md

@@ -15,19 +15,15 @@ Enjoy and please do feel free to feedback experiences and issues.
 
 ## Securing the API
 
-By default, the API is exposed so your interface can interact directly. In other words, anyone can go to `http://your-device:9090/v1/connect` to send commands to your device. If you would prefer to only allow access from your backend, change the following line in run.py:
+By default, the API is exposed so your interface can interact directly. In other words, anyone can go to `http://your-device:9090/v1/connect` to send commands to your device. 
 
-```diff
-- app.run(port=9090, host='0.0.0.0')
-+ app.run(port=9090, host='127.0.0.1')
-```
-
-Then ensure your backend container is connected to the host network so it matches the API docker-compose.yml file in this repo:
+If you would prefer to only allow access from your backend, change the `host` environment variable to `127.0.0.1`. Then ensure your backend container is connected to the host network so it matches the API docker-compose.yml file in this repo:
 
 `network_mode: "host"`
 
 Users will then be unable to access the API `http://your-device:9090/v1/connect`. Your backend container on the device, however, can reach the API using `http://127.0.0.1:9090/v1/connect`. This is useful if your interface has a login process, and you only want users to be able to interact with Wi-Fi after logging in.
 
+Alternatively, if you would rather have your backend use specified ports instead of the host network, you can change the `host` environment variable to `172.17.0.1` and access the API from `http://172.17.0.1:9090/v1/connect`.
 
 
 ## Endpoints

docker-compose.yml

@@ -1,10 +1,12 @@
 version: '2.1'
 
 services:
-  balena-py-wifi-connect:
+  py-wifi-connect:
     environment:
       HOTSPOT_SSID: "Py Wi-Fi Connect"
       #HOTSPOT_PASSWORD: "my-hotspot-password" # Hotspot passwords must be 8 characters or more.
+      HOST: "0.0.0.0"
+      PORT: 9090
       DBUS_SYSTEM_BUS_ADDRESS: "unix:path=/host/run/dbus/system_bus_socket"
     build:
       context: .

src/config.py

@@ -12,6 +12,18 @@
 else:
     hotspot_password = None
 
+# Set default host.
+if "HOST" in os.environ:
+    host = os.environ['HOST']
+else:
+    host = '0.0.0.0'
+
+# Set default port.
+if "PORT" in os.environ:
+    port = os.environ['PORT']
+else:
+    port = 9090
+
 # Default access point name. No need to change these under usual operation as
 # they are for use inside the app only. PWC is acronym for 'Py Wi-Fi Connect'.
 ap_name = 'PWC'

src/run.py

@@ -8,6 +8,8 @@
 from common.wifi import check_wifi_status
 from common.wifi import connect
 from common.wifi import refresh_networks
+from config import host
+from config import port
 from resources.system_routes import system_health_check
 from resources.wifi_routes import wifi_connect
 from resources.wifi_routes import wifi_connection_status
@@ -67,4 +69,4 @@ def handle_sigterm(*args):
     # Initialise and start
     api.init_app(app)
 
-    app.run(port=9090, host='0.0.0.0')
+    app.run(port=port, host=host)