Dockerize front-end API

- Change URL of dependent services to env variables instead
    - Allow host names and ports to be specified dynamically on container creation
- Update requirements.txt with full list of packages
- Add Dockerfile
- Add API to docker-compose.yml as a new service

apis/front/Dockerfile

@@ -0,0 +1,8 @@
+# docker build -t evs-front-api .
+FROM python:3.9-alpine3.12
+
+COPY app.py requirements.txt demo.json ./
+RUN pip install --no-cache-dir -r requirements.txt
+
+EXPOSE 8080
+CMD ["gunicorn", "-b", "0.0.0.0:8080", "app:app"]

apis/front/app.py

@@ -1,15 +1,16 @@
 import logging
 import json
+import os
 import requests
 from flask import Flask, request
 from flask_cors import CORS
 from operator import itemgetter
 
-DB_API_HOST = 'localhost'
-DB_API_PORT = 8001
+DB_API_HOST = os.environ.get('DB_API_HOST', 'localhost')
+DB_API_PORT = os.environ.get('DB_API_PORT', 8001)
 
-WEB_API_HOST = 'localhost'
-WEB_API_PORT = 5000
+WEB_API_HOST = os.environ.get('WEB_API_HOST', 'localhost')
+WEB_API_PORT = os.environ.get('WEB_API_PORT', 5000)
 
 logging.basicConfig(format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
                     level=logging.INFO)

apis/front/requirements.txt

@@ -1,2 +1,4 @@
 flask
 flask-cors
+gunicorn
+requests

docker-compose.yml

@@ -48,6 +48,23 @@ services:
     container_name: evs_web_api
     ports:
       - "${WEB_API_PORT}:8080"
+    restart: "on-failure"
+
+  frontend_api:
+    depends_on:
+      - db_api
+      - web_api
+    build: apis/front
+    image: evs-front-api:latest
+    container_name: evs_front_api
+    ports:
+      - "${FRONTEND_API_PORT}:8080"
+    environment:
+      DB_API_HOST: "db_api"
+      DB_API_PORT: "8080"
+      WEB_API_HOST: "web_api"
+      WEB_API_PORT: "8080"
+    restart: "on-failure"
 
   telebot:
     depends_on: