Multiple flask applications with docker compose and nginx

This repository is an example of how you can use a single virtual environment in order to build and run multiple Python web applications with docker compose. It uses nginx as the reverse proxy and flask to create the web applications but this methodology will work with any Python web application software such as dash and streamlit. The apps are deployed using a production ready gunicorn server.

This repository will create the following resources:

• server certificate and key
• nginx server redirecting traffic to HTTPS
• base, an example Python base image for a flask web application
• app-1, a hello world Flask web application
• app-2, a hello world Flask web application

Prerequisites

• docker compose
• make

Getting started

To build the resources simplying follow the steps below:

1. Clone this repository and cd docker-flask-nginx.

2. Run the following command:

   make

3. Only applicable if nginx/certs/nginx.key and nginx/certs/nginx.crt don't exist: Answer the questions which are required to build the server certificate.

4. Visit https://localhost to see the nginx homepage with links to the 2 flask applications.

5. To take all the services down, simply run the following command:

   make down

The make command in step 2 will run make certs and make up, these can also be run separately for more control.

Server certificates

To secure the applications with HTTPS a server certificate is required, in this example it will create a self signed server certificate that would need to be registered to remove any insecure warnings. To create a self signed server certificate run the following command:

make certs

This command will ask a series of questions and then create two files nginx/certs/nginx.key and nginx/certs/nginx.crt that are used in the nginx/nginx.conf to secure the site with HTTPS. To see the commands in more detail, see Makefile.

Deploying the applications

To deploy the resources, a base image is created to avoid having to reinstall the same requirements and make deployments faster see base-env. Once this base environment is created it will be used in analytics/app-1 and analytics/app-2.

To build the base environment and the other services found in the docker-compose.yml, run the following command:

make up

To take it down and prune the environment, run the following command:

make down

To see the commands in more detail, see Makefile.