6.3. DevOps Docker

6.3.1. Requirements

• requirements.txt

Minimal Setup:

fastapi
uvicorn

Full Stack:

fastapi
pydantic
pydantic[email]
sqlalchemy
uvicorn[standard]
passlib[bcrypt]
python-jose[cryptography]
python-multipart

6.3.2. Official Image

• Dockerfile

FROM tiangolo/uvicorn-gunicorn-fastapi:python3.9
COPY . /app/

6.3.3. Custom Image

• Dockerfile

• requirements.txt

• docker-compose.yaml

File requirements.txt:

fastapi==0.78.*
pydantic==1.9.*
uvicorn[standard]==0.17.*
httpx==0.23.*

Note, that for alpine based images you cannot use Cython compiled uvicorn. In order to get speed improvement and production-ready highly-performant uvloop we will use python:3.10 debian based image instead.

File main.py:

>>> from fastapi import FastAPI
>>> app = FastAPI()
>>>
>>>
>>> @app.get('/healthcheck', status_code=200)
... async def healthcheck() -> bool:
...     return True

File Dockerfile

FROM python:3.10

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

COPY src /src
WORKDIR /src
CMD uvicorn main:app --host 0.0.0.0 --port 80

HEALTHCHECK --start-period=10s --interval=60s --timeout=3s --retries=3 \
  CMD curl --fail http://localhost:80/healthcheck || exit 1

File docker-compose.yaml

services:

  myapp:
    image: myusername/myapp:${VERSION:-latest}
    build: myusername/myapp
    command: uvicorn main:app --reload --host 0.0.0.0 --port 80
    volumes:
      - ./src:/src
      - ./tests:/tests