Add iam_only variable and remove import blocks

Author: ale210

.github/workflows/terraform-apply.yaml

@@ -38,4 +38,5 @@ jobs:
       with:
         path: terraform
         backend_config_file: terraform/prod.backend.tfvars
+        variables: iam_only = false
         auto_approve: ${{ github.event_name == 'workflow_dispatch' }}

.github/workflows/terraform-plan.yaml

@@ -34,3 +34,4 @@ jobs:
       with:
         path: terraform
         backend_config_file: terraform/prod.backend.tfvars
+        variables: iam_only = false

CONTRIBUTING.md

@@ -260,6 +260,15 @@ Remember to match these values to the ones in your backend state (and replace US
 ### **Terraform Setup and Execution Instructions**
 Make the required changes and execute them to see the changes in your own AWS account
 
+**Note:** By default this configuration manages IAM resources only (`iam_only = true`). The CloudTrail trails and log buckets in `cloudtrail.tf` belong to the Hack for LA AWS account and are skipped, so you don't need to set anything for a test run in your own account. Everything else is still created in your account, including:
+ * every IAM user this repo declares
+ * the `ops-leads` group, with `AdministratorAccess` attached
+ * a GitHub Actions OIDC provider. AWS allows only one per account, so `terraform apply` fails with `EntityAlreadyExists` if your account already has one.
+
+Run `terraform destroy` when you are finished to remove them.
+
+**Note:** Any plan or apply against the Hack for LA AWS account must pass `-var iam_only=false`. The GitHub Actions workflows already do this.
+
 - Change into `terraform` directory with 
 
 ```bash

terraform/aws-custom-policies-legacy.tf

@@ -9,7 +9,8 @@
 //
 // ManageAccessKeys is attached to the ops-leads group by
 // aws_iam_group_policy_attachment.manageAccessKeys in aws-groups.tf, which
-// still refers to it by literal ARN. That attachment is unchanged here.
+// refers to this resource's arn rather than a literal ARN, so it also resolves
+// in a contributor's own AWS account.
 
 resource "aws_iam_policy" "manage_access_keys" {
   name = "ManageAccessKeys"
@@ -19,8 +20,3 @@ resource "aws_iam_policy" "manage_access_keys" {
   description = "Policy for creating, listing, and updating Access Keys"
   policy      = file("${path.module}/aws-custom-policies/existing-policies/manage-access-keys-policy.json")
 }
-
-import {
-  to = aws_iam_policy.manage_access_keys
-  id = "arn:aws:iam::035866691871:policy/ManageAccessKeys"
-}

terraform/aws-groups-legacy.tf

@@ -13,8 +13,3 @@
 resource "aws_iam_group" "project_leads" {
   name = "project-leads"
 }
-
-import {
-  to = aws_iam_group.project_leads
-  id = "project-leads"
-}

terraform/aws-groups.tf

@@ -10,7 +10,7 @@ module "iam_read_only_group" {
   }
 }
 
-//import ops-leads group
+// ops-leads group
 resource "aws_iam_group" "ops_leads_group" {
 	name = "ops-leads"
 }
@@ -22,7 +22,7 @@ resource "aws_iam_group_policy_attachment" "admin"{
 
 resource "aws_iam_group_policy_attachment" "manageAccessKeys"{
 	group = aws_iam_group.ops_leads_group.name
-	policy_arn = "arn:aws:iam::035866691871:policy/ManageAccessKeys"
+	policy_arn = aws_iam_policy.manage_access_keys.arn
 } 
 
 

terraform/aws-users-legacy.tf

@@ -21,13 +21,3 @@ resource "aws_iam_user" "fangyiliu" {
 resource "aws_iam_user" "jack_pashayan" {
   name = "jack.pashayan"
 }
-
-import {
-  to = aws_iam_user.fangyiliu
-  id = "fangyiliu"
-}
-
-import {
-  to = aws_iam_user.jack_pashayan
-  id = "jack.pashayan"
-}

terraform/cloudtrail.tf

@@ -17,6 +17,13 @@
 // indefinitely), and the disagreement over log file validation, which is reproduced below
 // rather than resolved.
 //
+// Everything here is skipped unless var.iam_only is false (see variables.tf). The bucket
+// names, bucket policies and the backend bucket selector all belong to the Hack for LA
+// account, so none of this can be created in a contributor's own AWS account. The CI
+// workflows set iam_only = false. The trails and buckets carry prevent_destroy so that a
+// run against the Hack for LA account which forgets to do the same fails at plan time
+// instead of planning to destroy the account's audit logging.
+//
 // A bucket is not one resource. Since AWS provider v4 the policy, public access block,
 // encryption and ownership controls are each their own resource with their own import --
 // the same trap terraform/import.tf in hackforla/incubator documents.
@@ -26,7 +33,13 @@
 // ---------------------------------------------------------------------------
 
 resource "aws_s3_bucket" "tf_backend_logs" {
+  count = var.iam_only ? 0 : 1
+
   bucket = "aws-cloudtrail-logs-035866691871-4b8654bf"
+
+  lifecycle {
+    prevent_destroy = true
+  }
 }
 
 // Reproduced verbatim from the live bucket. These two statements are what let CloudTrail
@@ -38,7 +51,9 @@ resource "aws_s3_bucket" "tf_backend_logs" {
 // equivalent to AWS, and both are left exactly as stored. Normalising them would be a
 // change to a live policy for no behavioural gain.
 resource "aws_s3_bucket_policy" "tf_backend_logs" {
-  bucket = aws_s3_bucket.tf_backend_logs.id
+  count = var.iam_only ? 0 : 1
+
+  bucket = aws_s3_bucket.tf_backend_logs[0].id
 
   policy = jsonencode({
     Version = "2012-10-17"
@@ -73,7 +88,9 @@ resource "aws_s3_bucket_policy" "tf_backend_logs" {
 }
 
 resource "aws_s3_bucket_public_access_block" "tf_backend_logs" {
-  bucket = aws_s3_bucket.tf_backend_logs.id
+  count = var.iam_only ? 0 : 1
+
+  bucket = aws_s3_bucket.tf_backend_logs[0].id
 
   block_public_acls       = true
   block_public_policy     = true
@@ -84,7 +101,9 @@ resource "aws_s3_bucket_public_access_block" "tf_backend_logs" {
 // blocked_encryption_types is deliberately not set. The provider reads it back as
 // ["SSE-C"] on both buckets but it is computed, so leaving it out produces no diff.
 resource "aws_s3_bucket_server_side_encryption_configuration" "tf_backend_logs" {
-  bucket = aws_s3_bucket.tf_backend_logs.id
+  count = var.iam_only ? 0 : 1
+
+  bucket = aws_s3_bucket.tf_backend_logs[0].id
 
   rule {
     apply_server_side_encryption_by_default {
@@ -98,7 +117,9 @@ resource "aws_s3_bucket_server_side_encryption_configuration" "tf_backend_logs"
 // equivalent resource is declared for it below -- declaring one would create it rather
 // than import it, which is a live change.
 resource "aws_s3_bucket_ownership_controls" "tf_backend_logs" {
-  bucket = aws_s3_bucket.tf_backend_logs.id
+  count = var.iam_only ? 0 : 1
+
+  bucket = aws_s3_bucket.tf_backend_logs[0].id
 
   rule {
     object_ownership = "BucketOwnerEnforced"
@@ -109,8 +130,10 @@ resource "aws_s3_bucket_ownership_controls" "tf_backend_logs" {
 // the provider's default_tags would plan to REMOVE it, which is why this is the one
 // resource in this file carrying a tags block.
 resource "aws_cloudtrail" "tf_backend_logs" {
+  count = var.iam_only ? 0 : 1
+
   name                          = "devops-security-tf-backend-logs"
-  s3_bucket_name                = aws_s3_bucket.tf_backend_logs.id
+  s3_bucket_name                = aws_s3_bucket.tf_backend_logs[0].id
   include_global_service_events = true
   is_multi_region_trail         = true
   enable_log_file_validation    = true
@@ -133,20 +156,32 @@ resource "aws_cloudtrail" "tf_backend_logs" {
   tags = {
     project = "devops-security"
   }
+
+  lifecycle {
+    prevent_destroy = true
+  }
 }
 
 // ---------------------------------------------------------------------------
 // management-events -- the account's management events
 // ---------------------------------------------------------------------------
 
 resource "aws_s3_bucket" "management_events" {
+  count = var.iam_only ? 0 : 1
+
   bucket = "aws-cloudtrail-logs-035866691871-6539ef03"
+
+  lifecycle {
+    prevent_destroy = true
+  }
 }
 
 // Verbatim from the live bucket, including the "AWS:SourceArn" spelling -- see the note on
 // the policy above.
 resource "aws_s3_bucket_policy" "management_events" {
-  bucket = aws_s3_bucket.management_events.id
+  count = var.iam_only ? 0 : 1
+
+  bucket = aws_s3_bucket.management_events[0].id
 
   policy = jsonencode({
     Version = "2012-10-17"
@@ -181,7 +216,9 @@ resource "aws_s3_bucket_policy" "management_events" {
 }
 
 resource "aws_s3_bucket_public_access_block" "management_events" {
-  bucket = aws_s3_bucket.management_events.id
+  count = var.iam_only ? 0 : 1
+
+  bucket = aws_s3_bucket.management_events[0].id
 
   block_public_acls       = true
   block_public_policy     = true
@@ -190,7 +227,9 @@ resource "aws_s3_bucket_public_access_block" "management_events" {
 }
 
 resource "aws_s3_bucket_server_side_encryption_configuration" "management_events" {
-  bucket = aws_s3_bucket.management_events.id
+  count = var.iam_only ? 0 : 1
+
+  bucket = aws_s3_bucket.management_events[0].id
 
   rule {
     apply_server_side_encryption_by_default {
@@ -203,8 +242,10 @@ resource "aws_s3_bucket_server_side_encryption_configuration" "management_events
 // Log file validation is off on this trail and on for the other. That inconsistency is
 // reproduced rather than resolved -- turning it on is a live change and its own ticket.
 resource "aws_cloudtrail" "management_events" {
+  count = var.iam_only ? 0 : 1
+
   name                          = "management-events"
-  s3_bucket_name                = aws_s3_bucket.management_events.id
+  s3_bucket_name                = aws_s3_bucket.management_events[0].id
   include_global_service_events = true
   is_multi_region_trail         = true
   enable_log_file_validation    = false
@@ -217,4 +258,8 @@ resource "aws_cloudtrail" "management_events" {
       equals = ["Management"]
     }
   }
+
+  lifecycle {
+    prevent_destroy = true
+  }
 }

terraform/imports.tf

@@ -0,0 +1,12 @@
+// Defaults to true so that a contributor running this against their own AWS account,
+// which is how changes are tested (see CONTRIBUTING.md), gets IAM resources only. The
+// resources in cloudtrail.tf are specific to the Hack for LA account and cannot be
+// created anywhere else.
+//
+// Any plan or apply against the Hack for LA account MUST set this to false. Both CI
+// workflows do. See hackforla/devops-security#196.
+variable "iam_only" {
+  description = "Manage IAM resources only, skipping the Hack for LA account's CloudTrail trails and log buckets. Set to false for the Hack for LA account."
+  type        = bool
+  default     = true
+}