Add support for image_tag_mutability_exclusion_filter in ECR repositories

[Copilot]

This PR implements support for the image_tag_mutability_exclusion_filter feature in AWS ECR repositories, allowing fine-grained control over tag mutability settings.

Problem

ECR repositories previously only supported global image_tag_mutability settings (MUTABLE or IMMUTABLE), which applied to all tags uniformly. This created limitations in scenarios where users needed mixed mutability - for example, keeping production tags immutable while allowing development tags like latest, dev-*, or feature-* to be mutable.

Solution

Added comprehensive support for image_tag_mutability_exclusion_filter which allows users to define specific tag patterns that should be excluded from the repository's global mutability setting.

Key Changes

1. New Variable: Added image_tag_mutability_exclusion_filter variable with proper type definition:

   image_tag_mutability_exclusion_filter = [
     {
       filter      = "latest"
       filter_type = "WILDCARD"
     },
     {
       filter      = "dev-"
       filter_type = "WILDCARD"
     }
   ]

2. Dynamic Resource Block: Implemented dynamic block in aws_ecr_repository resource to conditionally apply exclusion filters.

3. Comprehensive Validation: Added validation rules to ensure:

   • filter_type must be a valid value (WILDCARD)
   • filter values cannot be empty or whitespace-only

4. Provider Version Update: Updated minimum AWS provider version to >= 6.8.0 to support this feature across all modules and examples.

Usage Example

module "ecr" {
  source = "cloudposse/ecr/aws"
  
  namespace              = "company"
  stage                  = "prod"
  name                   = "api"
  image_tag_mutability   = "IMMUTABLE_WITH_EXCLUSIONS"
  
  # Allow specific tag patterns to be mutable while keeping others immutable
  image_tag_mutability_exclusion_filter = [
    {
      filter      = "latest"
      filter_type = "WILDCARD"
    },
    {
      filter      = "dev-"
      filter_type = "WILDCARD"
    }
  ]
}

This enables scenarios where production tags remain immutable for safety, while development and utility tags maintain flexibility for iterative workflows.

Documentation

Updated README.md with comprehensive documentation including:

• Advanced usage examples showing real-world scenarios
• Provider version requirements and migration notes
• Complete variable reference in the inputs table

Testing

• ✅ All Terraform validation passes
• ✅ Formatting checks pass across all modules
• ✅ Variable validation correctly catches invalid configurations
• ✅ Examples updated and validated
• ✅ Backward compatibility maintained

Breaking Changes

This is an additive feature that defaults to an empty list, preserving existing behavior.

HOWEVER the AWS Provider is updated two major versions.

Requirements

• AWS Provider >= 6.8.0 (updated across all modules and examples)
• Terraform >= 0.13.0 (unchanged)

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• checkpoint-api.hashicorp.com
  • Triggering command: terraform version (dns block)
  • Triggering command: terraform init (dns block)
  • Triggering command: terraform fmt -check (dns block)
• esm.ubuntu.com
  • Triggering command: /usr/lib/apt/methods/https (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

This pull request was created as a result of the following prompt from Copilot chat.

Implement support for image_tag_mutability_exclusion_filter in the AWS ECR repository resource in main.tf. This entails:

• Adding a new variable to the module for configuring exclusion filters.
• Using a dynamic block for image_tag_mutability_exclusion_filter in the resource, referencing the new variable(s).
• Documenting the new variable(s) in the README.md, with usage examples and a note about the minimum AWS provider version (>= 6.8.0).
• Updating versions.tf to bump the minimum AWS provider version to 6.8.0.
• Updating changelog and examples if needed.

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[mergify]

This pull request was automatically closed as it no longer contains any changes.

This typically happens when another merged pull request has already included this request's
proposed modifications into the default branch.

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[github-actions]

These changes were released in v1.0.0.