Fake API in Python with Flask

README.md

Concept

Quickly create a fake API for testing client with Python and Flask.

Inspired by https://github.com/gchaincl/httplab seemed a bit heavyweight for my needs.

You can create responses in httplab.json file. "Responses" maps path to status, headers, body (content) returned (text or json). You can specify a delay for realisim.

httplab.json

{
  "Headers": {
    "Server": "PyHttpLab"
  },
  "Delay": 500,
  "Responses": {
    "": {
      "Status": 200,
      "Delay": 0,
      "Body": "home"
    },
    "ok": {
      "Status": 200,
      "Delay": 0,
      "Body": "Hello, World",
      "Headers": {
        "X-Server": "HTTPLab"
      }
    },
    "item/32": {
      "Status": 200,
      "Delay": 0,
      "Body": {
        "item": 32,
        "title": "item_32"
      }
    },
    "create": {
      "Status": 201,
      "Delay": 1000,
      "Body": {
        "created": "ok"
      },
      "Headers": {
        "Content-Type": "application/json"
      }
    },
    "notfound": {
      "Status": 404,
      "Delay": 0,
      "Body": "Page Not Found",
      "Headers": {}
    }
  }
}

main.py

# inspired by https://github.com/gchaincl/httplab
import time
from flask import Flask, json, jsonify, request, make_response

app = Flask(__name__)

with open("httplab.json") as f:
    config = json.load(f)

indent = config["Indent"] if "Indent" in config else 2
common_headers = config["Headers"] if "Headers" in config else {}
site_delay = config["Delay"] if "Delay" in config else 0

@app.route('/', defaults={'path': ''})
@app.route('/<path:path>')
def catch_all(path):
    if path in config['Responses']:
        response = config['Responses'][path]
    else:
        response = {
            "Status": 404,
            "Body": "Page {} Not Found".format(path)
        }
    status = response["Status"] if "Status" in response else 200
    body = response["Body"] if "Body" in response else {}
    page_headers = response["Headers"] if "Headers" in response else {}
    delay = response["Delay"] if "Delay" in response else site_delay
    if delay > 0:
        delay_secs = delay/1000.0
        print("delay {} seconds", delay_secs)
        time.sleep(delay_secs)
    if isinstance(body, dict):
        resp = make_response(json.dumps(response["Body"], indent=indent), status)
        resp.headers['Content-Type'] = 'application/json; charset=utf-8'
        resp.headers['mimetype'] = 'application/json'
    elif isinstance(body, str):
        resp = make_response(response["Body"], status)
    else:
        resp = make_response("None", status)
    for key, val in common_headers.items():
        resp.headers[key] = val
    for key, val in page_headers.items():
        resp.headers[key] = val
    return resp

if __name__ == "__main__":
    app.run(port=10080)