Deleting a resource from Template when using CDK Override?

[chadinwork]

Referencing the documentation here: https://aws.github.io/copilot-cli/docs/developing/overrides/cdk/

If we would like to delete a Resource from the template (this.template) how do we do that?

The documentation example shows us how to add new resources to a template, and how to delete a resource property, but not how to delete a resource.

Thank you!

[KollaAdithya]

Hello @chadinwork !

For example this sample adds a property to EnvironmentMangerRole

CDK overrides sample

import * as cdk from 'aws-cdk-lib'; import * as path from 'path'; import { aws_iam as iam } from 'aws-cdk-lib';

interface TransformedStackProps extends cdk.StackProps {
readonly appName: string;
readonly envName: string;
}

export class TransformedStack extends cdk.Stack {
public readonly template: cdk.cloudformation_include.CfnInclude;
public readonly appName: string;
public readonly envName: string;

constructor (scope: cdk.App, id: string, props: TransformedStackProps) {
    super(scope, id, props);
    this.template = new cdk.cloudformation_include.CfnInclude(this, 'Template', {
        templateFile: path.join('.build', 'in.yml'),
    });
    this.appName = props.appName;
    this.envName = props.envName;
    this.transformEnvironmentManagerRole();
}

transformEnvironmentManagerRole() {
    const environmentManagerRole = this.template.getResource("EnvironmentManagerRole") as iam.CfnRole;
    if (this.envName === "prod") {
        let assumeRolePolicy = environmentManagerRole.assumeRolePolicyDocument
        let statements = assumeRolePolicy.Statement
        statements.push({
             "Effect": "Allow",
             "Principal": { "Service": "ec2.amazonaws.com" },
             "Action": "sts:AssumeRole"
        })
    }
}

}

If you want to delete this property added to EnvironmentManagerRole you can just remove the transformEnvironmentManagerRole() on the CDK construct.

If you run copilot env deploy --name prod this will be delete the property set as a part of CDK overrides on EnvironmentMangerRole.

[chadinwork]

I'm not looking to delete a property. I'm looking to delete a resource. Such as delete a Cloudwatch Log Group.

[KollaAdithya]

Hi @chadinwork !
For example with this cdk L1 construct I am creating a new log group from CDK overrides in the service CloudFormation stack.


import * as cdk from 'aws-cdk-lib';
import * as logs from 'aws-cdk-lib/aws-logs';
import * as path from 'path';

interface TransformedStackProps extends cdk.StackProps {
  readonly appName: string;
  readonly envName: string;
}

export class TransformedStack extends cdk.Stack {
  public readonly template: cdk.cloudformation_include.CfnInclude;
  public readonly appName: string;
  public readonly envName: string;

  constructor(scope: cdk.App, id: string, props: TransformedStackProps) {
    super(scope, id, props);
    this.template = new cdk.cloudformation_include.CfnInclude(this, 'Template', {
      templateFile: path.join('.build', 'in.yml'),
    });
    this.appName = props.appName;
    this.envName = props.envName;
    this.addnewLoggroupResource();
  }

  addnewLoggroupResource() {
    // Create a new LogGroup
    const newLogGroup = new logs.LogGroup(this, 'MyLogGroup', {
      logGroupName: this.appName+"LogGroup",
      retention: logs.RetentionDays.FIVE_MONTHS,
    });
  }
}



After just removing the this.addnewLoggroupResource() and running copilot svc deploy again will just delete the log group created.

let me know if this helps!

[KollaAdithya]

May be i misinterpreted the question. sorry for all the churn.
If you want to delete the default LogGroup created by Copilot you can use this override

import * as cdk from 'aws-cdk-lib';
import * as path from 'path';

interface TransformedStackProps extends cdk.StackProps {
  readonly appName: string;
  readonly envName: string;
}

export class TransformedStack extends cdk.Stack {
  public readonly template: cdk.cloudformation_include.CfnInclude;
  public readonly appName: string;
  public readonly envName: string;

  constructor(scope: cdk.App, id: string, props: TransformedStackProps) {
    super(scope, id, props);
    this.template = new cdk.cloudformation_include.CfnInclude(this, 'Template', {
      templateFile: path.join('.build', 'in.yml'),
    });
    this.appName = props.appName;
    this.envName = props.envName;
    this.template.node.tryRemoveChild("LogGroup")
  }
}

[KollaAdithya]

I also created this PR (#5153) that will update our docs to showcase this example on deletion of a resource.

[chadinwork]

Thank you so much!