[ec2] Volume construct throws with fresh CDK app

[ddneilson]

If you have an app with an aws-ec2.Volume within it, then that app will throw a failed validation exception during the first fresh run of the app. This is because the VPC is not set up with true availability zones during this first run; instead it is set up with a dummy VPC -

aws-cdk/packages/@aws-cdk/aws-ec2/lib/vpc.ts

Line 1941 in b0f8729

const DUMMY_VPC_PROPS: cxapi.VpcContextResponse = {

Reproduction Steps

0. Set up my AWS temp credentials.
1. mkdir ebs_test; cd ebs_test
2. npx cdk@1.51.0 init --language=typescript app
3. Modify package.json to include "@aws-cdk/aws-ec2": "1.51.0", as a dependency
4. Copy repro case from below into bin/ebs_test.ts (overwriting existing contents)

import * as cdk from '@aws-cdk/core';
import * as ec2 from '@aws-cdk/aws-ec2';
const app = new cdk.App();
const env = {
    account: process.env.CDK_DEFAULT_ACCOUNT,
    region: process.env.CDK_DEFAULT_REGION
}
const stack = new cdk.Stack(app, 'Testing', { env });
const vpc = new ec2.Vpc(stack, 'Vpc');
new ec2.Volume(stack, 'Volume', {
  availabilityZone: vpc.availabilityZones[0],
  size: cdk.Size.gibibytes(8),
});

5. npx cdk@1.51.0 deploy Testing

Error Log

`availabilityZone` is a region followed by a letter (ex: `us-east-1a`), or a token

Environment

• CLI Version : 1.49.1+
• Framework Version: 1.49.1+
• Node.js Version: v10.16.3
• OS : Linux
• Language (Version): all

Other

The Volume code was introduced in #8219

---

This is 🐛 Bug Report

[ericzbeard]

@ddneilson I was not able to repro this issue with 1.51 in us-east-1. The stack created with no errors.

[ddneilson]

@ddneilson I was not able to repro this issue with 1.51 in us-east-1. The stack created with no errors.

@ericzbeard Don't know what to tell you. I can reproduce it every time I try...

0) Set up my AWS temp credentials.

1) mkdir ebs_test; cd ebs_test

2) npx cdk@1.51.0 init --language=typescript app

3) Modify package.json to include "@aws-cdk/aws-ec2": "1.51.0", as a dependency

4) Copy repro case from above into bin/ebs_test.ts (overwriting existing contents)

5) yarn install

6) npx cdk@1.51.0 deploy Testing
npx: installed 217 in 3.547s
`availabilityZone` is a region followed by a letter (ex: `us-east-1a`), or a token

[NetaNir]

When the cdk.context.json file does not exist, like in the case of the first run of a fresh application, the value will be dummy until it will be resolved by the CLI. This the expected behavior, the volume construct should not validate the availabilityZones at all, additionally the dummy# values should not be relied on, as they are not a part of the public API. The right solution here is to remove the validation from the construct.

[ddneilson]

When the cdk.context.json file does not exist, like in the case of the first run of a fresh application, the value will be dummy until it will be resolved by the CLI. This the expected behavior, the volume construct should not validate the availabilityZones at all, additionally the dummy# values should not be relied on, as they are not a part of the public API. The right solution here is to remove the validation from the construct.

That's certainly easy. Will get that up right now as a change to the attached PR.