Add boto3 script to fetch environment variables for development

.gitignore

@@ -9,3 +9,4 @@ infrastructure/cognitolambda/node_modules
 public/*
 /frontend/tsconfig.tsbuildinfo
 .idea/
+.env

DEVELOPMENT.md

@@ -10,6 +10,11 @@ export API_BASE_URL=https://[API_ID].execute-api.us-east-2.amazonaws.com/prod  #
 export ENV=dev
 ```
 
+If you have boto3 installed and have set your AWS credentials, you can run this script to fetch the necessary environment variables:
+```bash
+python3 scripts/generate_env.py $PCUI_STACK_NAME && source .env
+```
+
 If you don't have a virtual environment setup already, you can run from the base dir of the project:
 ```bash
 python3 -m venv venv

scripts/generate_env.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+import boto3
+import sys
+from os import path
+
+try: 
+    pcui_stack_name = sys.argv[1]
+except:
+	raise TypeError("Please provide a base PCUI stack name")
+
+client = boto3.client('cloudformation')
+
+def get_nested_stack_name(logical_id):
+	nested_stack = client.describe_stack_resource(StackName=pcui_stack_name, LogicalResourceId=logical_id)
+	return nested_stack['StackResourceDetail']['PhysicalResourceId']
+
+def get_output(stack_name, output_key):
+	pcui_stack = client.describe_stacks(StackName=stack_name)
+	for output in pcui_stack['Stacks'][0]['Outputs']:
+		if output['OutputKey'] == output_key:
+			return output['OutputValue']
+
+pc_api_stack_name = get_nested_stack_name('ParallelClusterApi')
+pcui_cognito_stack_name = get_nested_stack_name('Cognito')
+outpath = f"{path.dirname(path.dirname(__file__))}/.env"
+
+with open(outpath, 'w') as file:
+	file.write(f"export API_BASE_URL={get_output(pc_api_stack_name, 'ParallelClusterApiInvokeUrl')}\n")
+	file.write("export ENV=dev\n")
+	file.write(f"export SECRET_ID={get_output(pcui_stack_name, 'UserPoolClientSecretName')}\n")
+	file.write("export SITE_URL=http://localhost:5001\n")
+	file.write(f"export AUDIENCE={get_output(pcui_stack_name, 'AppClientId')}\n")
+	file.write(f"export AUTH_PATH={get_output(pcui_cognito_stack_name, 'UserPoolAuthDomain')}")
+
+print(f"Wrote to {outpath}")