add Dockerfile for local development without python

- Add a Dockerfile to run the application without needing to install any python dependencies (or even python itself!)
- Update app.py to bind to 0.0.0.0 in DEV mode so it can respond inside a container
- Update Contributing.md with instructions for building and running a containerized version of the webapp

.dockerignore

@@ -0,0 +1,6 @@
+.git
+.github
+*.md
+.dockerignore
+Dockerfile
+License.txt

CONTRIBUTING.md

@@ -80,6 +80,14 @@ you can wrap the command in a loop to restart the server quickly).
 (.env)$ env FLASK_ENV=development python app.py
 # or in a loop if it stops too often
 (.env)$ while true; do env FLASK_ENV=development python app.py; sleep 1; done
+
+If you want to run the website locally, but would prefer to use Docker instead of installing python, you can build a container and run it like so:
+```bash
+docker build -t NAME_OF_CONTAINER .
+```
+and then
+```bash
+docker run -it --rm -p 5000:5000 NAME_OF_CONTAINER
 ```
 
 If you don't want to use a website, you can run the code locally without the need of a website. To create a file use:

Dockerfile

@@ -0,0 +1,15 @@
+FROM ubuntu:20.04
+
+RUN apt update -y && apt install -y python3.8 python3-pip
+
+COPY requirements.txt /tmp/requirements.txt
+
+RUN pip3 install -r /tmp/requirements.txt
+
+WORKDIR /app
+
+COPY . .
+
+EXPOSE 5000
+
+ENTRYPOINT ["python3.8", "app.py"]

app.py

@@ -775,4 +775,7 @@ def update_yaml():
 
 if __name__ == '__main__':
     # Threaded option to enable multiple instances for multiple user access support
-    app.run(threaded=True, port=config ['port'])
+    if version() == 'DEV':
+        app.run(threaded=True, port=config ['port'], host="0.0.0.0")
+    else:
+        app.run(threaded=True, port=config ['port'])