[PYTHON] Build a lightweight Fast API development environment using Docker

Introduction

Recently, I often use Fast API, and I wanted to build it quickly with Docker and throw it away. As a memo, I would like to leave a way to build it lightweight.

Preparation

--Environment where Docker and Docker Compose can be used

version

$ docker --version
Docker version 19.03.8, build afacb8b7f0

--The file structure looks like this

file organization

.
├── Dockerfile
├── docker-compose.yml
├── main.py
└── requirements.txt

Source

You can clone from here https://github.com/sattosan/sample-fastapi-alpine

Dockerfile Made based on alpine

Dockerfile

FROM python:3.8-alpine

WORKDIR /app

ADD requirements.txt .
#Install the required packages inside the container
RUN apk add --no-cache build-base mariadb-connector-c-dev
# requirements.Install the Python packages listed in txt
RUN pip install --no-cache-dir --trusted-host pypi.python.org -r requirements.txt

ADD main.py .
#Wait for FastAPI on port 8000
CMD ["uvicorn", "main:app", "--reload", "--host", "0.0.0.0", "--port", "8000"]

Docker Compose

docker-compose.yml

version: "3.0"

services:
  # FastAPI
  api:
    container_name: "api"
    build: .
    restart: always
    tty: true
    ports:
      - 8000:8000

We have put together the necessary packages

requirements.txt

uvicorn
fastapi

Sample code

I have prepared the sample code in the FastAPI documentation (https://fastapi.tiangolo.com/).

main.py

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}

Run

$ docker-compose up -d --build

Check Docker Image size

--Alpine-based Image size

docker images | grep api
latest              bff0158b61ca        29 minutes ago      275MB

--Image size of the head family

It is the result of building with reference to Honke

$ docker images | grep api
latest              878110f2207f        11 seconds ago      1.02GB

You can see that it was reduced by 3.6 times compared to the original family

Operation check

APIs generated by FastAPI are automatically documented by Swagger

Take a look at Swagger

You can see the documentation by accessing domain / docs

http://localhost:8000/docs

Try to hit the API

If you hit it with curl, it will come back like this

result

$ curl localhost:8000
{"Hello":"World"}

in conclusion

This time, I tried to build a lightweight development environment based on alpine.

It is 3.6 times lighter than the original house, so I think it is a sufficient environment for disposable items. Recently, the Fast API has begun to be used in various projects including Netflix, so If you haven't used it yet, please try it!

--Netflix OSS: https://netflixtechblog.com/introducing-dispatch-da4b8a2a8072

Reference site

--Honke: https://fastapi.tiangolo.com/