setup.sh

#!/usr/bin/env bash

# pre-reqs
useradd user_api_svc
mkdir -p /usr/local/user_api/
pip3 install fastapi uvicorn pynamodb requests

# Adding users file for DB population
cat << EOF >> /usr/local/user_api/users.csv
Sheldon,Cooper,sheldon@caltech.edu,62612312345
Leonard,Hofstadter,leonard@caltech.edu,62612312345
Howard,Wolowitz,howard@caltech.edu,62612312345
Rajesh,Koothrappali,rajesh@caltech.edu,62612312345
Penny,Teller-Hofstadter,penny@cheescakefactory.com,62612312345
EOF

# Create main.py
cat << EOF >> /usr/local/user_api/main.py
import csv
from fastapi import FastAPI, status
from fastapi.responses import JSONResponse, RedirectResponse
from dynamo_model import UserModel

app = FastAPI(
    title="User API Service",
    description="User management API",
    version="1.0.0",
)

def get_user_details(first_name=None, last_name=None, get_all=False):
    return_data = list()
    if get_all:
        result = UserModel.scan()
    else:
        result = UserModel.query(first_name, UserModel.last_name == last_name)
        
    for x in result:
        return_data.append(x)
        
    return return_data
        
@app.get("/health")
def health():
    return JSONResponse(status_code=status.HTTP_200_OK, content={"Status": "Healthy"})

@app.get("/")
def root():
    return RedirectResponse(url='/docs')
    
@app.get("/user/")
def return_user_data(first: str, last: str):
    """
    Returns user information for a specific user
    """
    try:
        user_details = get_user_details(first_name=first, last_name=last)[0]
        return JSONResponse({
            "FirstName": user_details.first_name,
            "LastName": user_details.last_name,
            "PhoneNumber": user_details.phone,
            "EmailAddress": user_details.email
        })
    except:
        return JSONResponse(status_code=status.HTTP_404_NOT_FOUND, content={"Response": "User not found"})

@app.get("/all_users")
def get_all_users():
    all_users = get_user_details(get_all=True)
    return_data = list()
    for user_details in all_users:
        return_data.append({
            "FirstName": user_details.first_name,
            "LastName": user_details.last_name,
            "PhoneNumber": user_details.phone,
            "EmailAddress": user_details.email
        })
    return return_data

@app.post("/load_db")
def load_data():
    try:
        with open('./users.csv', 'r') as csvfile:
            csv_data = csv.reader(csvfile)
            for row in csv_data:
                UserModel(
                    first_name=row[0], 
                    last_name=row[1],
                    email=row[2],
                    phone=row[3]
                ).save()
        return JSONResponse(status_code=status.HTTP_200_OK, content={"Status": "Success"})
    except Exception as e:
        print(e)
        return JSONResponse(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, content={"Status": "Failed"})
        
        
if __name__ == '__main__':
    import uvicorn
    uvicorn.run("main:app", host="0.0.0.0", port=8080, log_level="info")
EOF

# Adding dynamodb data model class
cat << EOF >> /usr/local/user_api/dynamo_model.py
from pynamodb.models import Model
from pynamodb.attributes import UnicodeAttribute
from os import getenv

def get_region():
    from requests import get
    from json import loads
    try:
        region = loads(get('http://169.254.169.254/latest/dynamic/instance-identity/document').text).get('region')
    except:
        region = 'us-west-2'
    return region

class UserModel(Model):
    """
    User table
    """
    class Meta:
        table_name = getenv('DYNAMO_TABLE')
        region = get_region()
        
    email = UnicodeAttribute(null=True)
    phone = UnicodeAttribute(null=True)
    first_name = UnicodeAttribute(hash_key=True)
    last_name = UnicodeAttribute(range_key=True)

EOF

# Making application files executable
chmod +x /usr/local/user_api/main.py
chmod +x /usr/local/user_api/dynamo_model.py