docs: document docker container

Closes: #66

README.md

@@ -12,7 +12,11 @@ Development Setup
 -----------------
 
 For development, it is possible to use SQLite and a single host.
-
+Clone this repository and navigate to it:
+```
+git clone https://gitlab.com/guardianproject-ops/bypass-censorship/portal
+cd portal
+```
 Create and activate a Python virtual environment:
 
 ```
@@ -35,7 +39,8 @@ flask db upgrade
 ```
 
 Before the application can be run, it will need to be configured.
-Run `cp config.yaml.example config.yaml`, then edit `config.yaml` accordingly. Note that at least one cloud provider must be configured for the application to start successfully.
+Run `cp config.yaml.example config.yaml`, then edit `config.yaml` accordingly. Note that at least one cloud provider
+must be configured for the application to start successfully.
 To run the application:
 
 ```
@@ -43,12 +48,41 @@ flask run --host=0.0.0.0 --port=5000
 ```
 
 ### New frontend
+
 To build the new portal frontend:
 
 ```
 make install-frontend
 ```
 
+To update the build for the new portal frontend:
+
+```
+pushd frontend && git pull --ff-only && popd && make install-frontend
+```
+
+### Docker
+
+The dockerfile supplied will build a container to run the application:
+
+```
+docker build -t <image-name> .  
+
+docker|podman run -e WAITRESS_THREADS=4" -e WAITRESS_RUN_HOST="0.0.0.0" -e WAITRESS_RUN_PORT="5000" -e APP="bc" -e APP_BASE="/srv" <image_name>
+```
+
+The following environment variables can be set to configure the container:
+
+- ```WAITRESS_THREADS```: the number of Waitress worker threads for handling requests. Defaults to 4 threads.
+
+- ```WAITRESS_RUN_HOST```: the network interfaces on which Waitress will listen on inside the container. Defaults to
+  0.0.0.0 (all).
+
+- ```WAITRESS_RUN_PORT```: the port on which Waitress will serve the application inside the container. Defaults to 5000.
+
+- ```APP```: the app directory name, defaults to ```bc```.
+
+- ```APP_BASE```: the base directory where the app directory will be created. Defaults to ```/srv```.
 
 Copyright
 ---------