Supported tags and respective `Dockerfile` links

Deprecated tags

🚨 These tags are no longer supported or maintained, they are removed from the GitHub repository, but the last versions pushed might still be available in Docker Hub if anyone has been pulling them:

python3.8-alpine
python3.6
python2.7

The last date tags for these versions are:

python3.8-alpine-2024-03-11
python3.6-2022-11-25
python2.7-2022-11-25

Note: There are tags for each build date. If you need to "pin" the Docker image version you use, you can select one of those tags. E.g. tiangolo/uwsgi-nginx:python3.7-2019-09-28.

uwsgi-nginx

Docker image with uWSGI and Nginx for web applications in Python (as Flask) in a single container.

Description

This Docker image allows you to create Python web applications that run with uWSGI and Nginx in a single container.

The combination of uWSGI with Nginx is a common way to deploy Python web applications like Flask and Django. It is widely used in the industry and would give you decent performance. (*)

This image was created to be the base image for tiangolo/uwsgi-nginx-flask but could be used as the base image for any other (WSGI-based) Python web application, like Django.

* Note on performance and features

If you are starting a new project, you might benefit from a newer and faster framework based on ASGI instead of WSGI (Flask and Django are WSGI-based).

You could use an ASGI framework like:

FastAPI (which is based on Starlette) with this Docker image: tiangolo/uvicorn-gunicorn-fastapi.
Starlette directly, with this Docker image: tiangolo/uvicorn-gunicorn-starlette.
Or any other ASGI framework with this Docker image: tiangolo/uvicorn-gunicorn.

FastAPI, or Starlette, would give you about 800% (8x) the performance achievable with this image (tiangolo/uwsgi-nginx). You can see the third-party benchmarks here.

Also, if you want to use new technologies like WebSockets it would be easier (and possible) with a newer framework based on ASGI, like FastAPI or Starlette. As the standard ASGI was designed to be able to handle asynchronous code like the one needed for WebSockets.

If you need a WSGI-based application (like Flask or Django)

If you need to use an older WSGI-based framework like Flask or Django (instead of something based on ASGI) and you need to have the best performance possible, you can use the alternative image: tiangolo/meinheld-gunicorn.

tiangolo/meinheld-gunicorn will give you about 400% (4x) the performance of this image.

GitHub repo: https://github.com/tiangolo/uwsgi-nginx-docker

Docker Hub image: https://hub.docker.com/r/tiangolo/uwsgi-nginx/

🚨 WARNING: You Probably Don't Need this Docker Image

You are probably using Kubernetes or similar tools. In that case, you probably don't need this image (or any other similar base image). You are probably better off building a Docker image from scratch.

If you have a cluster of machines with Kubernetes, Docker Swarm Mode, Nomad, or other similar complex system to manage distributed containers on multiple machines, then you will probably want to handle replication at the cluster level instead of using a process manager in each container that starts multiple worker processes, which is what this Docker image does.

In those cases (e.g. using Kubernetes) you would probably want to build a Docker image from scratch, installing your dependencies, and running a single process instead of this image.

For example, using Gunicorn you could have a file app/gunicorn_conf.py with:

# Gunicorn config variables
loglevel = "info"
errorlog = "-"  # stderr
accesslog = "-"  # stdout
worker_tmp_dir = "/dev/shm"
graceful_timeout = 120
timeout = 120
keepalive = 5
threads = 3

And then you could have a Dockerfile with:

FROM python:3.9

WORKDIR /code

COPY ./requirements.txt /code/requirements.txt

RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt

COPY ./app /code/app

CMD ["gunicorn", "--conf", "app/gunicorn_conf.py", "--bind", "0.0.0.0:80", "app.main:app"]

You can read more about these ideas in the FastAPI documentation about: FastAPI in Containers - Docker as the same ideas would apply to other web applications in containers.

When to Use this Docker Image

A Simple App

You could want a process manager running multiple worker processes in the container if your application is simple enough that you don't need (at least not yet) to fine-tune the number of processes too much, and you can just use an automated default, and you are running it on a single server, not a cluster.

Docker Compose

You could be deploying to a single server (not a cluster) with Docker Compose, so you wouldn't have an easy way to manage replication of containers (with Docker Compose) while preserving the shared network and load balancing.

Then you could want to have a single container with a process manager starting several worker processes inside, as this Docker image does.

Prometheus and Other Reasons

You could also have other reasons that would make it easier to have a single container with multiple processes instead of having multiple containers with a single process in each of them.

For example (depending on your setup) you could have some tool like a Prometheus exporter in the same container that should have access to each of the requests that come.

In this case, if you had multiple containers, by default, when Prometheus came to read the metrics, it would get the ones for a single container each time (for the container that handled that particular request), instead of getting the accumulated metrics for all the replicated containers.

Then, in that case, it could be simpler to have one container with multiple processes, and a local tool (e.g. a Prometheus exporter) on the same container collecting Prometheus metrics for all the internal processes and exposing those metrics on that single container.

Read more about it all in the FastAPI documentation about: FastAPI in Containers - Docker, as the same concepts apply to other web applications in containers.

How to use

You don't have to clone this repo.

You can use this image as a base image for other images.

Assuming you have a file requirements.txt, you could have a Dockerfile like this:

FROM tiangolo/uwsgi-nginx:python3.11

COPY ./requirements.txt /app/requirements.txt

RUN pip install --no-cache-dir --upgrade -r /app/requirements.txt

COPY ./app /app

# Your Dockerfile code...

By default it will try to find a uWSGI config file in /app/uwsgi.ini.
That uwsgi.ini file will make it try to run a Python file in /app/main.py.

If you are building a Flask web application you should use instead tiangolo/uwsgi-nginx-flask.

Advanced usage

Custom app directory

If you need to use a directory for your app different than /app, you can override the uWSGI config file path with an environment variable UWSGI_INI, and put your custom uwsgi.ini file there.

For example, if you needed to have your application directory in /application instead of /app, your Dockerfile would look like:

FROM tiangolo/uwsgi-nginx:python3.11

ENV UWSGI_INI /application/uwsgi.ini

COPY ./application /application
WORKDIR /appapplication

And your uwsgi.ini file in ./application/uwsgi.ini would contain:

[uwsgi]
wsgi-file=/application/main.py

Note: it's important to include the WORKDIR option, otherwise uWSGI will start the application in /app.

Custom uWSGI process number

By default, the image starts with 2 uWSGI processes running. When the server is experiencing a high load, it creates up to 16 uWSGI processes to handle it on demand.

If you need to configure these numbers you can use environment variables.

The starting number of uWSGI processes is controlled by the variable UWSGI_CHEAPER, by default set to 2.

The maximum number of uWSGI processes is controlled by the variable UWSGI_PROCESSES, by default set to 16.

Have in mind that UWSGI_CHEAPER must be lower than UWSGI_PROCESSES.

So, if, for example, you need to start with 4 processes and grow to a maximum of 64, your Dockerfile could look like:

FROM tiangolo/uwsgi-nginx:python3.11

ENV UWSGI_CHEAPER 4
ENV UWSGI_PROCESSES 64

COPY ./app /app

Custom max upload size

In this image, Nginx is configured to allow unlimited upload file sizes. This is done because by default a simple Python server would allow that, so that's the simplest behavior a developer would expect.

If you need to restrict the maximum upload size in Nginx, you can add an environment variable NGINX_MAX_UPLOAD and assign a value corresponding to the standard Nginx config client_max_body_size.

For example, if you wanted to set the maximum upload file size to 1 MB (the default in a normal Nginx installation), you would need to set the NGINX_MAX_UPLOAD environment variable to the value 1m. Then the image would take care of adding the corresponding configuration file (this is done by the entrypoint.sh).

So, your Dockerfile would look something like:

FROM tiangolo/uwsgi-nginx:python3.11

ENV NGINX_MAX_UPLOAD 1m

COPY ./app /app

Custom listen port

By default, the container made from this image will listen on port 80.

To change this behavior, set the LISTEN_PORT environment variable.

You might also need to create the respective EXPOSE Docker instruction.

You can do that in your Dockerfile, it would look something like:

FROM tiangolo/uwsgi-nginx:python3.11

ENV LISTEN_PORT 8080

EXPOSE 8080

COPY ./app /app

Custom `/app/prestart.sh`

If you need to run anything before starting the app, you can add a file prestart.sh to the directory /app. The image will automatically detect and run it before starting everything.

For example, if you want to add database migrations that are run on startup (e.g. with Alembic, or Django migrations), before starting the app, you could create a ./app/prestart.sh file in your code directory (that will be copied by your Dockerfile) with:

#! /usr/bin/env bash

# Let the DB start
sleep 10;
# Run migrations
alembic upgrade head

and it would wait 10 seconds to give the database some time to start and then run that alembic command (you could update that to run Django migrations or any other tool you need).

If you need to run a Python script before starting the app, you could make the /app/prestart.sh file run your Python script, with something like:

#! /usr/bin/env bash

# Run custom Python script before starting
python /app/my_custom_prestart_script.py

Note: The image uses . to run the script (as in . /app/prestart.sh), so for example, environment variables would persist. If you don't understand the previous sentence, you probably don't need it.

Custom Nginx processes number

By default, Nginx will start one "worker process".

If you want to set a different number of Nginx worker processes you can use the environment variable NGINX_WORKER_PROCESSES.

You can use a specific single number, e.g.:

ENV NGINX_WORKER_PROCESSES 2

or you can set it to the keyword auto and it will try to autodetect the number of CPUs available and use that for the number of workers.

For example, using auto, your Dockerfile could look like:

FROM tiangolo/uwsgi-nginx:python3.11

ENV NGINX_WORKER_PROCESSES auto

COPY ./app /app

Custom Nginx maximum connections per worker

By default, Nginx will start with a maximum limit of 1024 connections per worker.

If you want to set a different number you can use the environment variable NGINX_WORKER_CONNECTIONS, e.g:

ENV NGINX_WORKER_CONNECTIONS 2048

It cannot exceed the current limit on the maximum number of open files. See how to configure it in the next section.

Custom Nginx maximum open files

The number connections per Nginx worker cannot exceed the limit on the maximum number of open files.

You can change the limit of open files with the environment variable NGINX_WORKER_OPEN_FILES, e.g.:

ENV NGINX_WORKER_OPEN_FILES 2048

Customizing Nginx additional configurations

If you need to configure Nginx further, you can add *.conf files to /etc/nginx/conf.d/ in your Dockerfile.

Just have in mind that the default configurations are created during startup in a file at /etc/nginx/conf.d/nginx.conf and /etc/nginx/conf.d/upload.conf. So you shouldn't overwrite them. You should name your *.conf file with something different than nginx.conf or upload.conf, for example: custom.conf.

Note: if you are customizing Nginx, maybe copying configurations from a blog or a StackOverflow answer, have in mind that you probably need to use the configurations specific to uWSGI, instead of those for other modules, like for example, ngx_http_fastcgi_module.