ec2-provider

Simple Flask API with Flask on EC2

This is a simple REST API authored in Python with Flask. The actual API is less important than the connection mechansim that it provides. The aim of this is to demonstrate how to access this API using a VPC Endpoint from another AWS Account.

Setting up

1. Export three environment variables:

   API_GATEWAY_ACCOUNT_ARN is the ARN for the account which owns the single API Gateway HTTP API. We will call this the "API Gateway Account". That API Gateway will be created later using a different repo/CDK code. Note that this stack must be created first.

   $ export API_GATEWAY_ACCOUNT_ARN="arn:aws:iam::111111111111:root"
   $ export AWS_ACCOUNT=333333333333
   $ export AWS_REGION=us-west-2

2. Deploy the two stacks. This can be done via the Makefile with make deploy, or manually with cdk deploy --all.

   Make note of the outputs from the todo-stack. You will need this value when setting up the Global API Gateway stack:

   ec2-provider.ec2vpcendpointservicename = com.amazonaws.vpce.us-west-2.vpce-svc-xxxxxxxxxxxxxxxxx

3. Once deployed, there will be two stacks: 1) VPC Stack and 2) Todo API stack. Remember that the EC2 instances live in private subnets and the only way to get network access is to be inside the VPC. You should see that 2 of 2 instances are in service when looking at the Network Load Balancer in the AWS console. You can optionally create a bastion host within the VPC and make http requests to the network load balancer.

   Without a bastion host, you will access this Todo API via the global API Gateway endpoint created from the Global API Gateway application.

   $ # assuming you have a bastion host
   $ ssh -i your-key-pair.pem ec2-user@ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
   >
   > # fetch all of the items
   > curl http://nlb-xxxxxxxxxxxxxxxx.elb.us-west-2.amazonaws.com:8080
   >
   > # create new todos
   > curl -d data=one http://nlb-xxxxxxxxxxxxxxxx.elb.us-west-2.amazonaws.com:8080
   > curl -d data=two http://nlb-xxxxxxxxxxxxxxxx.elb.us-west-2.amazonaws.com:8080
   > curl -d data=three http://nlb-xxxxxxxxxxxxxxxx.elb.us-west-2.amazonaws.com:8080
   >
   > # fetch them again
   > curl http://nlb-xxxxxxxxxxxxxxxx.elb.us-west-2.amazonaws.com:8080
   >
   > # fetch a single item
   > curl http://nlb-xxxxxxxxxxxxxxxx.elb.us-west-2.amazonaws.com:8080/ab234df
   >