FastAPI and Spring Boot Admin in Docker Compose

Overview

The pyctuator github page explains that while "many Java shops use Spring Boot as their main web framework ... and Spring Boot Admin to monitor their microservicess", often their is a need to "integrate a couple of Python microservices". Pyctuator "allows you to easily integrate your Python microservices into your existing Spring Boot Admin deployment."

I found myself in this situation recently, with a fastAPI application that needed to be integrated into a sea of java spring apps. Being able to integrate this application into the existing Spring Boot Admin application significantly reduced resistance associated with using a different technology.

In this blog post I will demostrate setting up a FastAPI application to work with Spring Boot Admin. Its pretty straight forward.

Demo

The required directory / file structure looks like this

. base directory 
├── docker-compose.yml 
├── main.py            ## this file is our sample FastAPI application 
└── Dockerfile         ## this file builds our FastAPI application

The content of the three files is provided below (click the tab heading to expand):

main.py

from fastapi import FastAPI
from pyctuator.pyctuator import Pyctuator

app = FastAPI(title="FastAPI Sample App")

@app.get("/")
def hello():
    return {"sample": "response"}

Pyctuator(
    app,
    "FastAPI Sample App",
    app_url="http://app:80",
    pyctuator_endpoint_url="http://app:80/pyctuator",
    registration_url="http://spring-admin:8080/instances"
)

Dockerfile

FROM tiangolo/uvicorn-gunicorn-fastapi:python3.7

RUN pip install --no-cache-dir pyctuator

COPY ./main.py /app/main.py

Docker-Compose

version: "2.2"
services:
  app:
    build:
      context: ./
    ports:
    - 80:80
    networks:
      - test
  spring-admin:
    image: michayaak/spring-boot-admin:2.2.3-1
    ports:
    - 8080:8080
    networks:
      - test

networks:
  test:

Once the files have been created just run docker-compose up and the sample FastAPI app and the Spring Boot Admin app will both boot up. Now open your browser and open

• http://localhost:80/docs to see the sample FastAPI application
• http://localhost:8080 to see the Spring Boot Admin app

The below screenshots show the Sample FastAPI App within Spring Boot Admin.

Spring Boot Admin Wallboard

FastAPI in Spring Boot Admin

That was easy - wasn't it?