Merge pull request #1 from QuanticSchool/working

Initial API gateway and client

api-gateway/.gitignore

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+/api-gateway-env

api-gateway/apis.json

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+[
+    {
+        "api_name": "immortal_memes",
+        "api_type": "HTTP",
+        "integrations": {
+            "0": {"type": "lambda", "region": "us-east-1", "function": "im-health-check"}
+        },
+        "routes": [
+            {"method": "GET", "path": "/health-check", "integration_id": "0"}
+        ]
+    }
+]

api-gateway/application.py

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+# Copyright 2022 Quantic School of Business and technology
+#
+# This Flask application emulates part of the functionality of an
+# AWS API Gateway using Elastic Beanstalk. It was written because
+# the AWS Learner Lab does not allow for the use of API Gateway.
+#
+# The following functionality from the API Gateway is emulated. If
+# a capability isn't specifically mentioned (e.g. a $default stage),
+# assume it's not implemented:
+#
+#    API types: HTTP
+#    Integrations: Lambda
+#    Methods: any (including the ANY method specifier)
+#    Path variables: yes, except for greedy variables.
+#
+# For more information on Flask, see 
+# https://flask.palletsprojects.com/en/2.1.x/. A few notes:
+#
+#    - To initialize a Flask web server, you add routes that the
+#      server will respond to using add_url_rule(). Part of each
+#      URL rule is a view function that gets called when the 
+#      URL path matches the rule.
+#    - When the server processes a request, Flask sets a global
+#      variable named request with the details of the request.
+#
+# This application uses the boto3 library to invoke AWS Lambda
+# functions. You can learn more about boto3 here:
+# https://boto3.amazonaws.com/v1/documentation/api/latest/index.html
+
+from flask import Flask, request
+import json, boto3
+from botocore.config import Config
+
+# Elastic Beanstalk looks for a callable named application
+application = Flask(__name__)
+
+class LambdaInvoker():
+    """Represents a callable invoker for an AWS Lambda function.
+
+    Normally you pass add_url_rule a view_func. However, we needed to
+    have a way to associate the view_func with a particular AWS
+    Lambda function. So we actually make a callable object that
+    has as attributes the Lambda function and path.
+    
+    Attributes:
+        region: A string with the region containing the Lambda to invoke.
+                Note that this feature is untested for cases in which the
+                Lambda is in a different region than the Elastic Beanstalk
+                instance running the API Gateway emulator.
+        function: A string with the name of the Lambda to invoke.
+        path: A string with the URL path for this route.
+    """
+    def __init__(self, region, function, path):
+        self.region = region
+        self.function = function
+        self.path = path
+
+    def __call__(self, **path_params):
+        """Invokes the Lambda.
+        
+        Invokes the Lambda function and returns the response. This is called
+        by Flask based on URL rules added to the application with
+        add_url_rule().
+        
+        Args:
+            path_params: A dictionary with the parameters in the path (e.g. if
+                         the route was specified as /foo/{bar} and the path is
+                         /foo/42, the dictionary will be {"bar": 42}).
+
+        Returns:
+            The response from the Lambda function, or an error message.
+        """
+
+        # build the payload the lambda function expects to see. see
+        # https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-develop-integrations-lambda.html
+        # for details on the payload that an API Gateway sends a Lambda.
+        # we omit requestContext (TODO see about including later) and 
+        # stageVariables (didn't appear in an actual payload sent to 
+        # Lambda from API Gateway). 
+        payload = {
+            "version": "2.0",
+            "routeKey": f"{request.method} {self.path}",
+            "rawPath": request.path,
+            "rawQueryString": str(request.query_string),
+            "cookies": [
+                f"{cookie[0]}={cookie[1]}" for cookie in request.cookies.items()
+            ],
+            "headers": dict(request.headers),
+            "queryStringParameters": dict(request.args),
+            "body": request.get_data(as_text=True),
+            "isBase64Encoded": False
+        }
+
+        if (path_params):
+            payload["pathParameters"] = path_params
+
+        # invoke the Lambda function. We don't need to specify credentials
+        # if we give the Elastic Beanstalk instance a role
+        invoke_config = Config(
+            region_name=self.region
+        )
+        client = boto3.client("lambda", config=invoke_config)
+        response = client.invoke(
+            FunctionName=self.function,
+            InvocationType="RequestResponse",
+            Payload=json.dumps(payload)
+        )
+
+        # now send the response
+        if response["StatusCode"] != 200:
+            return response["FunctionError"], response["StatusCode"]
+        else:
+            return response["Payload"].read()
+
+# convenience function to raise an exception if a required dictionary
+# entry is missing
+def get_required_entry(dictionary, key, exception_text):
+    """Raises an exception if a required dictionary key is missing.
+    
+    Args:
+        dictionary: The dictionary.
+        key: The key.
+        exception_text: The text of the exception.
+        
+    Returns:
+        The value for the given key.
+        
+    Raises:
+        Exception: the key wasn't found.
+    """
+    result = dictionary.get(key)
+
+    if not result:
+        raise Exception(exception_text)
+
+    return result
+
+# load the API(s) from a config file
+config = None
+
+try:
+    with open("apis.json") as config_file:
+        apis = json.load(config_file)
+except Exception as err:
+    err_str = f"Config file error: {err}"
+    application.add_url_rule(
+        "/",
+        endpoint="config_err",
+        view_func=lambda: err_str
+    )
+    apis = []
+
+# build the route handlers
+try:
+    for api in apis:
+        api_name = get_required_entry(
+            api,
+            "api_name",
+            "API missing required api_name"
+        )
+        api_type = get_required_entry(
+            api,
+            "api_type",
+            f"API {api_name} missing required type"
+        )
+
+        if api_type == "HTTP":
+            routes = get_required_entry(
+                api,
+                "routes",
+                f"API {api_name} missing required routes"
+            )
+            integrations = get_required_entry(
+                api,
+                "integrations",
+                f"API {api_name} missing required integrations"
+            )
+
+            for route in routes:
+                method = get_required_entry(
+                    route,
+                    "method",
+                    f"Route in API {api_name} missing required method"
+                )
+
+                if method == "ANY":
+                    method = None
+
+                path = get_required_entry(
+                    route,
+                    "path",
+                    f"Route in API {api_name} missing required path"
+                )
+                integration_id = get_required_entry(
+                    route,
+                    "integration_id",
+                    f"Route in API {api_name} missing required integration_id"
+                )
+                integration = get_required_entry(
+                    integrations,
+                    integration_id,
+                    f"API {api_name} missing integration_id {integration_id}"
+                )
+                integration_type = get_required_entry(
+                    integration,
+                    "type",
+                    f"integration_id {integration_id} missing required type"
+                )
+
+                if integration_type == "lambda":
+                    region = get_required_entry(
+                        integration,
+                        "region",
+                        f"integration_id {integration_id} missing required region"
+                    )
+                    function = get_required_entry(
+                        integration,
+                        "function",
+                        f"integration_id {integration_id} missing required function"
+                    )
+                    application.add_url_rule(
+                        # Flask uses <> for path variable delimiters
+                        path.replace("{", "<").replace("}", ">"), 
+                        endpoint=f"{path}_{region}_{function}",
+                        methods=[method] if method else None,
+                        view_func=LambdaInvoker(region, function, path)
+                    )
+                else:
+                    raise Exception(f"integration type {integration_type} not implemented")
+
+        else:
+            raise Exception(f"api type {api_type} not implemented")
+
+except Exception as err:
+    # reset the application and add an error route
+    application = Flask(__name__)
+    err_str = f"Gateway config error: {err}"
+    application.add_url_rule(
+        "/", 
+        endpoint="config_err", 
+        view_func=lambda: err_str
+    )
+
+# run the app.
+if __name__ == "__main__":
+    application.run()

api-gateway/requirements.txt

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+boto3==1.21.43
+botocore==1.24.43
+click==8.1.2
+colorama==0.4.4
+Flask==2.1.1
+importlib-metadata==4.11.3
+itsdangerous==2.1.2
+Jinja2==3.1.1
+jmespath==1.0.0
+MarkupSafe==2.1.1
+python-dateutil==2.8.2
+s3transfer==0.5.2
+six==1.16.0
+urllib3==1.26.9
+Werkzeug==2.1.1
+zipp==3.8.0

client/.gitignore

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+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+/.pnp
+.pnp.js
+
+# testing
+/coverage
+
+# production
+#/build
+
+# misc
+.DS_Store
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*

client/README.md

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+# Getting Started with Create React App
+
+This project was bootstrapped with [Create React App](https://github.com/facebook/create-react-app).
+
+## Available Scripts
+
+In the project directory, you can run:
+
+### `npm start`
+
+Runs the app in the development mode.\
+Open [http://localhost:3000](http://localhost:3000) to view it in your browser.
+
+The page will reload when you make changes.\
+You may also see any lint errors in the console.
+
+### `npm test`
+
+Launches the test runner in the interactive watch mode.\
+See the section about [running tests](https://facebook.github.io/create-react-app/docs/running-tests) for more information.
+
+### `npm run build`
+
+Builds the app for production to the `build` folder.\
+It correctly bundles React in production mode and optimizes the build for the best performance.
+
+The build is minified and the filenames include the hashes.\
+Your app is ready to be deployed!
+
+See the section about [deployment](https://facebook.github.io/create-react-app/docs/deployment) for more information.
+
+### `npm run eject`
+
+**Note: this is a one-way operation. Once you `eject`, you can't go back!**
+
+If you aren't satisfied with the build tool and configuration choices, you can `eject` at any time. This command will remove the single build dependency from your project.
+
+Instead, it will copy all the configuration files and the transitive dependencies (webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except `eject` will still work, but they will point to the copied scripts so you can tweak them. At this point you're on your own.
+
+You don't have to ever use `eject`. The curated feature set is suitable for small and middle deployments, and you shouldn't feel obligated to use this feature. However we understand that this tool wouldn't be useful if you couldn't customize it when you are ready for it.
+
+## Learn More
+
+You can learn more in the [Create React App documentation](https://facebook.github.io/create-react-app/docs/getting-started).
+
+To learn React, check out the [React documentation](https://reactjs.org/).
+
+### Code Splitting
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/code-splitting](https://facebook.github.io/create-react-app/docs/code-splitting)
+
+### Analyzing the Bundle Size
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/analyzing-the-bundle-size](https://facebook.github.io/create-react-app/docs/analyzing-the-bundle-size)
+
+### Making a Progressive Web App
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/making-a-progressive-web-app](https://facebook.github.io/create-react-app/docs/making-a-progressive-web-app)
+
+### Advanced Configuration
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/advanced-configuration](https://facebook.github.io/create-react-app/docs/advanced-configuration)
+
+### Deployment
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/deployment](https://facebook.github.io/create-react-app/docs/deployment)
+
+### `npm run build` fails to minify
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify](https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify)

client/build/asset-manifest.json

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+{
+  "files": {
+    "main.css": "/static/css/main.80c75857.css",
+    "main.js": "/static/js/main.e1bd46a3.js",
+    "index.html": "/index.html",
+    "main.80c75857.css.map": "/static/css/main.80c75857.css.map",
+    "main.e1bd46a3.js.map": "/static/js/main.e1bd46a3.js.map"
+  },
+  "entrypoints": [
+    "static/css/main.80c75857.css",
+    "static/js/main.e1bd46a3.js"
+  ]
+}

client/build/index.html

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+<!doctype html><html lang="en"><head><meta charset="utf-8"/><link rel="icon" href="/favicon.ico"/><meta name="viewport" content="width=device-width,initial-scale=1"/><meta name="theme-color" content="#000000"/><meta name="description" content="A web app to find memes that will live in immortality."/><link rel="apple-touch-icon" href="/logo192.png"/><link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png"><link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png"><link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png"><link rel="manifest" href="/manifest.json"/><link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous"><title>Immortal Memes!</title><script defer="defer" src="/static/js/main.e1bd46a3.js"></script><link href="/static/css/main.80c75857.css" rel="stylesheet"></head><body><noscript>You need to enable JavaScript to run this app.</noscript><div id="root"></div></body></html>