Tech Tips: Azure Container Apps

Summary

This is a continuation of a previous post on proxying a SOAP API to REST. In this post, I'll deploy the containerized proxy to Azure Container Apps and front end it with Azure API Management (APIM).

Architecture

Code

Proxy App

I modified the Python FastAPI app slightly to serve up an OpenAPI file. That file is used by APIM during provisioning.

from fastapi import FastAPI, HTTPException
from fastapi.responses import FileResponse
from zeep import Client
import logging

logging.getLogger('zeep').setLevel(logging.ERROR)
client = Client('https://www.w3schools.com/xml/tempconvert.asmx?wsdl')
app = FastAPI()

@app.get("/openapi.yml")
async def openapi():
    return FileResponse("openapi.yml")

@app.get("/CelsiusToFahrenheit")
async def celsiusToFahrenheit(temp: int): 
    try:
        soapResponse = client.service.CelsiusToFahrenheit(temp)
        fahrenheit = int(round(float(soapResponse),0))
    except:
        raise HTTPException(status_code=400, detail="SOAP request error")
    else:
        return {"temp": fahrenheit}


@app.get("/FahrenheitToCelsius")
async def fahrenheitToCelsius(temp: int): 
    try:
        soapResponse = client.service.FahrenheitToCelsius(temp)
        celsius = int(round(float(soapResponse),0))
    except:
        raise HTTPException(status_code=400, detail="SOAP request error")
    else:
        return {"temp": celsius}

OpenAPI Spec

swagger: '2.0'
info:
  title: apiproxy
  description: REST to SOAP proxy
  version: 1.0.0
schemes:
  - http
produces:
  - application/json
paths:
  /CelsiusToFahrenheit:
    get:
      summary: Convert celsius temp to fahrenheit
      parameters:
        - name: temp
          in: path
          required: true
          type: integer
      responses:
        '200':
          description: converted temp
          schema: 
            type: object
            properties:
              temp:
                type: integer
        '400':
          description: General error
  /FahrenheitToCelsius:
    get:
      summary: Convert fahrenheit temp to celsius
      parameters:
        - name: temp
          in: path
          required: true
          type: integer
      responses:
        '200':
          description: converted temp
          schema: 
            type: object
            properties:
              temp:
                type: integer
        '400':
          description: General error