Improve the AWS tagging in Terraform

[ben851]

Description

As a developer/operator of Notify, I want every resource that we create under the infrastructure as code in AWS to be tagged consistently across all environments

WHY

Consistent tagging allows operators the ability to quickly locate, identify, and track resources within AWS.

WHAT

We can investigate default tagging policies within AWS so that all resources that are created are automatically tagged with pre-determined default tags. We can then remove a lot of tagging objects from the terraform code, and only add tags on individual resources as required.

VALUE

Consistent tagging will ensure that we are fully aware of what resources are doing and what solution they are a part of. It will allow us to create management scripts that can target specific resources, which would be good for eliminating toil and environment automation.

Acceptance Criteria

• All future resources are automatically tagged as per the tagging policies defined in terraform.

QA Steps

• Deploy new resources and ensure resource tagging is done correctly
• Deploy the tagging policy to existing resources and ensure that they are tagged correctly

[jimleroyer]

Hey team! Please add your planning poker estimate with Zenhub @ben851 @sastels

[jimleroyer]

Seems like a duplicate of
https://app.zenhub.com/workspaces/notify-planning-core-6411dfb7c95fb80014e0cab0/issues/gh/cds-snc/notification-planning-core/9

[ben851]

Rated a little higher than the team, in Azure, automatic tagging policies were not very easy to set up. Maybe (hopefully) it's different in AWS

[sastels]

investigated a bit. AWS supports declaring default tags in the provider, however they're currently buggy. SRE spent some time looking into them but gave up because of the problems. The terraform folks plan to have the bugs fixed in the next major release of terraform (v5). See this Slack thread for more info.

Suggest we wait until version 5 of terraform is released.