feat: new aws_ecs_clusters datasource

[taufort]

Description

This datasource aims at getting all ECS clusters ARNs associated with an AWS account. It can be useful to get ECS clusters in case you don't know their names (in that case, the existing datasource aws_ecs_cluster won't be much help - see https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/ecs_cluster).

I was trying to set up centralized VPC flow logs in an AWS organization to send all flow logs to one common S3 bucket. On some AWS accounts in this organization, ECS clusters may exist or not. In case ECS clusters exist, I wanted to have ECS flow logs fields sent to the bucket (the ECS fields can be found here: https://docs.aws.amazon.com/vpc/latest/userguide/flow-log-records.html#flow-logs-fields). But to have those ECS fields in the flow logs, at least one ECS cluster must exist on the AWS account, else the Flow log cannot be created.

So, I came up with a workaround using a null_resource and a local-exec provisioner (using AWS CLI commands in it to get the list of ECS Clusters in the account) in order to be able to switch between 2 VPC flow logs format in case an ECS cluster exists on an AWS account. This way, I'm able to have ECS fields added in the flow log with the same code base as when no ECS cluster exists on the AWS account.

This new datasource will help me get rid of this workaround which is clearly not ideal.

Relations

I did not find a ticket related to the creation of this datasource.

Output from Acceptance Testing

❯ make testacc TESTS=TestAccECSClustersDataSource_basic PKG=ecs
make: Verifying source code with gofmt...
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go1.23.3 test ./internal/service/ecs/... -v -count 1 -parallel 20 -run='TestAccECSClustersDataSource_basic'  -timeout 360m
2024/12/19 17:56:58 Initializing Terraform AWS Provider...
=== RUN   TestAccECSClustersDataSource_basic
=== PAUSE TestAccECSClustersDataSource_basic
=== CONT  TestAccECSClustersDataSource_basic
--- PASS: TestAccECSClustersDataSource_basic (28.33s)
PASS
ok      github.com/hashicorp/terraform-provider-aws/internal/service/ecs        28.566s

[github-actions]

Community Note

Voting for Prioritization

• Please vote on this pull request by adding a 👍 reaction to the original post to help the community and maintainers prioritize this pull request.
• Please see our prioritization guide for information on how we prioritize.
• Please do not leave "+1" or other comments that do not add relevant new information or questions, they generate extra noise for issue followers and do not help prioritize the request.

For Submitters

• Review the contribution guide relating to the type of change you are making to ensure all of the necessary steps have been taken.
• For new resources and data sources, use skaff to generate scaffolding with comments detailing common expectations.
• Whether or not the branch has been rebased will not impact prioritization, but doing so is always a welcome surprise.

[ewbankkit]

LGTM 🚀.

% make testacc TESTARGS='-run=TestAccECSClustersDataSource_' PKG=ecs
make: Verifying source code with gofmt...
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go1.23.3 test ./internal/service/ecs/... -v -count 1 -parallel 20  -run=TestAccECSClustersDataSource_ -timeout 360m
2024/12/23 12:14:32 Initializing Terraform AWS Provider...
=== RUN   TestAccECSClustersDataSource_basic
=== PAUSE TestAccECSClustersDataSource_basic
=== CONT  TestAccECSClustersDataSource_basic
--- PASS: TestAccECSClustersDataSource_basic (22.21s)
PASS
ok  	github.com/hashicorp/terraform-provider-aws/internal/service/ecs	27.765s

[nam054]

LGTM 🚀

[ewbankkit]

@taufort Thanks for the contribution 🎉 👏.