add immutability exclusions (#57)

Author: Benbentwo

README.md

@@ -28,7 +28,6 @@ usage: |-
   typically provisioned via the stack for the "artifact" account (typically `auto`, `artifact`, or `corp`) in the primary
   region.
 
-  ```yaml
   components:
     terraform:
       ecr:
@@ -39,7 +38,14 @@ usage: |-
           scan_images_on_push: true
           protected_tags:
             - prod
-          image_tag_mutability: MUTABLE
+          # Tag mutability supports: MUTABLE, IMMUTABLE, IMMUTABLE_WITH_EXCLUSION, MUTABLE_WITH_EXCLUSION
+          image_tag_mutability: IMMUTABLE_WITH_EXCLUSION
+          # When using *_WITH_EXCLUSION, specify exclusions to allow certain tags to be mutable
+          image_tag_mutability_exclusion_filter:
+            - filter: "latest"
+              filter_type: "WILDCARD"
+            - filter: "dev-"
+              filter_type: "WILDCARD"
 
           images:
             - infrastructure

README.yaml

@@ -24,21 +24,22 @@ locals {
 
 module "ecr" {
   source  = "cloudposse/ecr/aws"
-  version = "0.44.0"
+  version = "1.0.0"
 
-  protected_tags                   = var.protected_tags
-  protected_tags_keep_count        = var.protected_tags_keep_count
-  enable_lifecycle_policy          = var.enable_lifecycle_policy
-  default_lifecycle_rules_settings = var.default_lifecycle_rules_settings
-  image_names                      = var.images
-  image_tag_mutability             = var.image_tag_mutability
-  max_image_count                  = var.max_image_count
-  principals_full_access           = compact(concat(module.full_access.principals, [local.ecr_user_arn]))
-  principals_readonly_access       = module.readonly_access.principals
-  principals_lambda                = var.principals_lambda
-  scan_images_on_push              = var.scan_images_on_push
-  use_fullname                     = false
-  replication_configurations       = var.replication_configurations
+  protected_tags                        = var.protected_tags
+  protected_tags_keep_count             = var.protected_tags_keep_count
+  enable_lifecycle_policy               = var.enable_lifecycle_policy
+  default_lifecycle_rules_settings      = var.default_lifecycle_rules_settings
+  image_names                           = var.images
+  image_tag_mutability                  = var.image_tag_mutability
+  image_tag_mutability_exclusion_filter = var.image_tag_mutability_exclusion_filter
+  max_image_count                       = var.max_image_count
+  principals_full_access                = compact(concat(module.full_access.principals, [local.ecr_user_arn]))
+  principals_readonly_access            = module.readonly_access.principals
+  principals_lambda                     = var.principals_lambda
+  scan_images_on_push                   = var.scan_images_on_push
+  use_fullname                          = false
+  replication_configurations            = var.replication_configurations
 
   custom_lifecycle_rules = var.custom_lifecycle_rules
 

src/main.tf

@@ -10,10 +10,35 @@ variable "images" {
 
 variable "image_tag_mutability" {
   type        = string
-  description = "The tag mutability setting for the repository. Must be one of: `MUTABLE` or `IMMUTABLE`"
+  description = "The tag mutability setting for the repository. Must be one of: `MUTABLE`, `IMMUTABLE`, `IMMUTABLE_WITH_EXCLUSION`, or `MUTABLE_WITH_EXCLUSION`"
   default     = "MUTABLE"
 }
 
+variable "image_tag_mutability_exclusion_filter" {
+  type = list(object({
+    filter      = string
+    filter_type = optional(string, "WILDCARD")
+  }))
+  default     = []
+  description = "List of exclusion filters for image tag mutability. Each filter object must contain 'filter' and 'filter_type' attributes. Requires AWS provider >= 6.8.0"
+
+  validation {
+    condition = alltrue([
+      for filter in var.image_tag_mutability_exclusion_filter :
+      contains(["WILDCARD"], filter.filter_type)
+    ])
+    error_message = "filter_type must be `WILDCARD`"
+  }
+
+  validation {
+    condition = alltrue([
+      for filter in var.image_tag_mutability_exclusion_filter :
+      length(trimspace(filter.filter)) > 0
+    ])
+    error_message = "filter value cannot be empty or contain only whitespace."
+  }
+}
+
 variable "max_image_count" {
   type        = number
   description = "Max number of images to store. Old ones will be deleted to make room for new ones."

src/variables.tf

@@ -4,7 +4,7 @@ terraform {
   required_providers {
     aws = {
       source  = "hashicorp/aws"
-      version = ">= 4.9.0, < 6.0.0"
+      version = ">= 6.8.0, < 7.0.0"
     }
   }
 }

src/versions.tf

@@ -20,6 +20,40 @@ type LifecyclePolicyRuleSelection struct {
     CountNumber   int      `json:"countNumber"`
 }
 
+func (s *ComponentSuite) TestImmutabilityExclusions() {
+    const component = "ecr/immutability-exclusions"
+    const stack = "default-test"
+    const awsRegion = "us-east-2"
+
+    suffix := strings.ToLower(random.UniqueId())
+
+    inputs := map[string]interface{}{
+        "images": []string{
+            fmt.Sprintf("infrastructure-%s", suffix),
+            fmt.Sprintf("microservice-a-%s", suffix),
+            fmt.Sprintf("microservice-b-%s", suffix),
+            fmt.Sprintf("microservice-c-%s", suffix),
+        },
+    }
+
+    defer s.DestroyAtmosComponent(s.T(), component, stack, &inputs)
+    options, _ := s.DeployAtmosComponent(s.T(), component, stack, &inputs)
+    assert.NotNil(s.T(), options)
+
+    arnMaps := map[string]string{}
+    atmos.OutputStruct(s.T(), options, "ecr_repo_arn_map", &arnMaps)
+
+    for name := range arnMaps {
+        repository := aws.GetECRRepo(s.T(), awsRegion, name)
+        // Assert new image tag mutability mode is applied
+        assert.EqualValues(s.T(), "IMMUTABLE_WITH_EXCLUSION", repository.ImageTagMutability)
+        // Existing expectations remain
+        assert.True(s.T(), repository.ImageScanningConfiguration.ScanOnPush)
+    }
+
+    s.DriftTest(component, stack, &inputs)
+}
+
 type LifecyclePolicyRule struct {
 	RulePriority int                          `json:"rulePriority"`
 	Description  string                       `json:"description"`

test/component_test.go

@@ -0,0 +1,25 @@
+components:
+  terraform:
+    ecr/immutability-exclusions:
+      metadata:
+        component: target
+      vars:
+        ecr_user_enabled: false
+        enable_lifecycle_policy: true
+        max_image_count: 500
+        scan_images_on_push: true
+        protected_tags:
+          - prod
+        image_tag_mutability: IMMUTABLE_WITH_EXCLUSION
+        image_tag_mutability_exclusion_filter:
+          - filter: "latest"
+            filter_type: "WILDCARD"
+          - filter: "dev-"
+            filter_type: "WILDCARD"
+        images:
+          - infrastructure
+          - microservice-a
+          - microservice-b
+          - microservice-c
+        read_write_account_role_map: {}
+        read_only_account_role_map: {}

test/fixtures/stacks/catalog/usecase/immutability-exclusions.yaml

@@ -2,3 +2,4 @@ import:
   - orgs/default/test/_defaults
   - catalog/usecase/basic
   - catalog/usecase/disabled
+  - catalog/usecase/immutability-exclusions