Supported tags and respective Dockerfile links

• python3.7-alpine3.8, latest (Dockerfile)

traefik-gunicorn-flask

This project is base on meinheld-gunicorn-flask-docker which already pack Gunicorn and Flask very well.

GitHub repo: https://github.com/WaynePN/traefik-gunicorn-flask/

Docker Hub image: https://hub.docker.com/r/waynepn/traefik-gunicorn-flask/

Technical Details

Traefik

Traefik is a high-performance cloud native edge router writen in Golang.

How to use

• You don't need to clone the GitHub repo. You can use this image as a base image for other images, using this in your Dockerfile:

FROM waynepn/traefik-gunicorn-flask

COPY ./app /app

It will expect a file at /app/app/main.py.

Or otherwise a file at /app/main.py.

And will expect it to contain a variable app with your "WSGI" application.

Then you can build your image from the directory that has your Dockerfile, e.g:

docker build -t myimage ./

Advanced usage

Environment variables

These are the environment variables that you can set in the container to configure it and their default values:

Gunicorn variables

APP_MODULE

The string with the Python module and the Flask application variable name passed to Gunicorn.

By default:

• main:app

For example, if your main file was at /app/custom_app/custom_main.py, you could set it like:

docker run -d -p 80:80 -e APP_MODULE="custom_app.custom_main:app" myimage

GUNICORN_CONF

The string path of Gunicorn python config file. By default:

• /gunicorn_conf.py

WORKERS_PER_CORE

This image will check how many CPU cores are available in the current server running your container.

It will set the number of workers to the number of CPU cores multiplied by this value.

By default:

• 2

You can set it like:

docker run -d -p 80:80 -e WORKERS_PER_CORE="3" myimage

If you used the value 3 in a server with 2 CPU cores, it would run 6 worker processes.

You can use floating point values too.

So, for example, if you have a big server (let's say, with 8 CPU cores) running several applications, and you have an ASGI application that you know won't need high performance. And you don't want to waste server resources. You could make it use 0.5 workers per CPU core. For example:

docker run -d -p 80:80 -e WORKERS_PER_CORE="0.5" myimage

In a server with 8 CPU cores, this would make it start only 4 worker processes.

LOG_LEVEL

The log level for Gunicorn.

One of:

• debug
• info
• warning
• error
• critical

By default:

• info.

If you need to squeeze more performance sacrificing logging, set it to warning, for example:

You can set it like:

docker run -d -p 80:80 -e LOG_LEVEL="warning" myimage

Traefik variables

TRAEFIK_CINFIG

The string path of Traefik config file.

By default:

• /etc/traefik/traefik.toml.

If you have custom Traefik file, for example:

You can set it like:

docker run -d -p 80:80 -e TRAEFIK_CINFIG="/app/traefik.toml" myimage

You can define listen port in Traefik config file, by default listen port is 80.