Adding Cloudfront addon fails

[vbarba]

Hi,

I am using the following template to add Cloudfront CDN in front of Load Balanced Web Service:

Parameters:
  App:
    Type: String
    Description: Your application's name.
  Env:
    Type: String
    Description: The environment name your service, job, or workflow is being deployed to.
  Name:
    Type: String
    Description: The name of the service, job, or workflow being deployed.
Resources:
  myDistribution:
    Type: 'AWS::CloudFront::Distribution'
    Properties:
      DistributionConfig:
        Origins:
        - DomainName:
            Fn::ImportValue:
              !Sub "${App}-${Env}-PublicLoadBalancerDNS"       
          Id: myCustomOrigin          
          CustomOriginConfig:
            HTTPPort: 80
            OriginProtocolPolicy: http-only
        Enabled: true
        Comment: !Sub "{$App}-${Env}-${Name}"
        DefaultCacheBehavior:
          TargetOriginId: myCustomOrigin
          ViewerProtocolPolicy: allow-all
          ForwardedValues:
            QueryString: false
            Cookies:
              Forward: all
        ViewerCertificate:
          CloudFrontDefaultCertificate: true

This works when the service was deployed before, but fails if this is deployed together for the first time because the

           Fn::ImportValue:
              !Sub "${App}-${Env}-PublicLoadBalancerDNS" 

Is not available until de Load Balanced Service is deployed.

Do you have any advice with this situation?

Thanks

[efekarakus]

Hi @vbarba 👋

Thanks for the issue! One way that might help mitigate the issue is possible to sleep in the cloudformation template before the myDistribution resource is created. We might be able to leverage the new CommandRunner resource type to do this.

1. Install CommandRunner to the CloudFormation registry: https://aws.amazon.com/blogs/mt/running-bash-commands-in-aws-cloudformation-templates/

2. Add a timer resource:

Resources:
  Waiter:
    Type: AWSUtility::CloudFormation::CommandRunner
    Properties:
      Command: 'sleep 4m'

  myDistribution:
    Type: 'AWS::CloudFront::Distribution'
    DependsOn: Waiter
    Properties: ...

3. If that works, we might be able to refine the Command to loop only until the load balancer is created.

We'll investigate in the mean time on our end if there is a simpler solution. Sorry for the inconvenience 🙇

[vbarba]

Hi,

I think that installing the CommandRunner into every account I need to deploy this is more complex than deploy the service itself. Also, create a EC2 instance (thats what CR do) to just run the sleep command is overkill.

At this moment, I moved this addon to the backend service and I deploy first the frontend (without addon) and then the backend (with the cdn addon).

Would be add a "DependsOn" to the Custom resource on the Nested stack possibility? This would enable the option to use the Exports from environment stack in the LoadBalancer type services addons.

Thanks!

[efekarakus]

Yea, that solution sounds good to us! We'll implement a fix

[efekarakus]

This is now released in https://github.com/aws/copilot-cli/releases/tag/v1.2.0!