Allow to restrict S3 access (#143)

* Allow to extend EC2 policy document

* Allow to use modern IAM policy for SSM access

* Fix version constraint for example script

* Add new features usage to example scripts

* Format files

* Update readme file

* Add better sample

* Updated README.md

Co-authored-by: Anton <[email protected]>
Co-authored-by: actions-bot <[email protected]>

Author: 3 people

README.md

@@ -175,6 +175,7 @@ Available targets:
 
 ```
 <!-- markdownlint-restore -->
+<!-- markdownlint-disable -->
 ## Requirements
 
 | Name | Version |
@@ -229,6 +230,7 @@ Available targets:
 | env\_vars | Map of custom ENV variables to be provided to the application running on Elastic Beanstalk, e.g. env\_vars = { DB\_USER = 'admin' DB\_PASS = 'xxxxxx' } | `map(string)` | `{}` | no |
 | environment | Environment, e.g. 'prod', 'staging', 'dev', 'pre-prod', 'UAT' | `string` | `""` | no |
 | environment\_type | Environment type, e.g. 'LoadBalanced' or 'SingleInstance'.  If setting to 'SingleInstance', `rolling_update_type` must be set to 'Time', `updating_min_in_service` must be set to 0, and `loadbalancer_subnets` will be unused (it applies to the ELB, which does not exist in SingleInstance environments) | `string` | `"LoadBalanced"` | no |
+| extended\_ec2\_policy\_document | Extensions or overrides for the IAM role assigned to EC2 instances | `string` | `"{}"` | no |
 | force\_destroy | Force destroy the S3 bucket for load balancer logs | `bool` | `false` | no |
 | health\_streaming\_delete\_on\_terminate | Whether to delete the log group when the environment is terminated. If false, the health data is kept RetentionInDays days. | `bool` | `false` | no |
 | health\_streaming\_enabled | For environments with enhanced health reporting enabled, whether to create a group in CloudWatch Logs for environment health and archive Elastic Beanstalk environment health data. For information about enabling enhanced health, see aws:elasticbeanstalk:healthreporting:system. | `bool` | `false` | no |
@@ -250,6 +252,7 @@ Available targets:
 | managed\_actions\_enabled | Enable managed platform updates. When you set this to true, you must also specify a `PreferredStartTime` and `UpdateLevel` | `bool` | `true` | no |
 | name | Solution name, e.g. 'app' or 'cluster' | `string` | n/a | yes |
 | namespace | Namespace, which could be your organization name, e.g. 'eg' or 'cp' | `string` | `""` | no |
+| prefer\_legacy\_ssm\_policy | Whether to use AmazonEC2RoleforSSM (will soon be deprecated) or AmazonSSMManagedInstanceCore policy | `bool` | `true` | no |
 | preferred\_start\_time | Configure a maintenance window for managed actions in UTC | `string` | `"Sun:10:00"` | no |
 | region | AWS region | `string` | n/a | yes |
 | rolling\_update\_enabled | Whether to enable rolling update | `bool` | `true` | no |
@@ -295,6 +298,7 @@ Available targets:
 | tier | The environment tier |
 | triggers | Autoscaling triggers in use by this environment |
 
+<!-- markdownlint-restore -->
 
 
 

docs/terraform.md

@@ -1,3 +1,4 @@
+<!-- markdownlint-disable -->
 ## Requirements
 
 | Name | Version |
@@ -52,6 +53,7 @@
 | env\_vars | Map of custom ENV variables to be provided to the application running on Elastic Beanstalk, e.g. env\_vars = { DB\_USER = 'admin' DB\_PASS = 'xxxxxx' } | `map(string)` | `{}` | no |
 | environment | Environment, e.g. 'prod', 'staging', 'dev', 'pre-prod', 'UAT' | `string` | `""` | no |
 | environment\_type | Environment type, e.g. 'LoadBalanced' or 'SingleInstance'.  If setting to 'SingleInstance', `rolling_update_type` must be set to 'Time', `updating_min_in_service` must be set to 0, and `loadbalancer_subnets` will be unused (it applies to the ELB, which does not exist in SingleInstance environments) | `string` | `"LoadBalanced"` | no |
+| extended\_ec2\_policy\_document | Extensions or overrides for the IAM role assigned to EC2 instances | `string` | `"{}"` | no |
 | force\_destroy | Force destroy the S3 bucket for load balancer logs | `bool` | `false` | no |
 | health\_streaming\_delete\_on\_terminate | Whether to delete the log group when the environment is terminated. If false, the health data is kept RetentionInDays days. | `bool` | `false` | no |
 | health\_streaming\_enabled | For environments with enhanced health reporting enabled, whether to create a group in CloudWatch Logs for environment health and archive Elastic Beanstalk environment health data. For information about enabling enhanced health, see aws:elasticbeanstalk:healthreporting:system. | `bool` | `false` | no |
@@ -73,6 +75,7 @@
 | managed\_actions\_enabled | Enable managed platform updates. When you set this to true, you must also specify a `PreferredStartTime` and `UpdateLevel` | `bool` | `true` | no |
 | name | Solution name, e.g. 'app' or 'cluster' | `string` | n/a | yes |
 | namespace | Namespace, which could be your organization name, e.g. 'eg' or 'cp' | `string` | `""` | no |
+| prefer\_legacy\_ssm\_policy | Whether to use AmazonEC2RoleforSSM (will soon be deprecated) or AmazonSSMManagedInstanceCore policy | `bool` | `true` | no |
 | preferred\_start\_time | Configure a maintenance window for managed actions in UTC | `string` | `"Sun:10:00"` | no |
 | region | AWS region | `string` | n/a | yes |
 | rolling\_update\_enabled | Whether to enable rolling update | `bool` | `true` | no |
@@ -118,3 +121,4 @@
 | tier | The environment tier |
 | triggers | Autoscaling triggers in use by this environment |
 
+<!-- markdownlint-restore -->

examples/complete/main.tf

@@ -95,4 +95,18 @@ module "elastic_beanstalk_environment" {
 
   additional_settings = var.additional_settings
   env_vars            = var.env_vars
+
+  extended_ec2_policy_document = data.aws_iam_policy_document.minimal_s3_permissions.json
+  prefer_legacy_ssm_policy     = false
+}
+
+data "aws_iam_policy_document" "minimal_s3_permissions" {
+  statement {
+    sid = "AllowS3OperationsOnElasticBeanstalkBuckets"
+    actions = [
+      "s3:ListAllMyBuckets",
+      "s3:GetBucketLocation"
+    ]
+    resources = ["*"]
+  }
 }

examples/complete/versions.tf

@@ -1,5 +1,5 @@
 terraform {
-  required_version = "~> 0.12.0"
+  required_version = ">= 0.12.0"
 
   required_providers {
     aws  = "~> 2.0"

main.tf

@@ -91,7 +91,7 @@ resource "aws_iam_role" "ec2" {
 resource "aws_iam_role_policy" "default" {
   name   = "${module.label.id}-eb-default"
   role   = aws_iam_role.ec2.id
-  policy = data.aws_iam_policy_document.default.json
+  policy = data.aws_iam_policy_document.extended.json
 }
 
 resource "aws_iam_role_policy_attachment" "web_tier" {
@@ -106,7 +106,7 @@ resource "aws_iam_role_policy_attachment" "worker_tier" {
 
 resource "aws_iam_role_policy_attachment" "ssm_ec2" {
   role       = aws_iam_role.ec2.name
-  policy_arn = "arn:aws:iam::aws:policy/service-role/AmazonEC2RoleforSSM"
+  policy_arn = var.prefer_legacy_ssm_policy ? "arn:aws:iam::aws:policy/service-role/AmazonEC2RoleforSSM" : "arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore"
 
   lifecycle {
     create_before_destroy = true
@@ -294,6 +294,11 @@ data "aws_iam_policy_document" "default" {
   }
 }
 
+data "aws_iam_policy_document" "extended" {
+  source_json   = data.aws_iam_policy_document.default.json
+  override_json = var.extended_ec2_policy_document
+}
+
 resource "aws_iam_instance_profile" "ec2" {
   name = "${module.label.id}-eb-ec2"
   role = aws_iam_role.ec2.name

variables.tf

@@ -489,4 +489,16 @@ variable "deployment_timeout" {
   type        = number
   default     = 600
   description = "Number of seconds to wait for an instance to complete executing commands"
-}
+}
+
+variable "extended_ec2_policy_document" {
+  type        = string
+  default     = "{}"
+  description = "Extensions or overrides for the IAM role assigned to EC2 instances"
+}
+
+variable "prefer_legacy_ssm_policy" {
+  type        = bool
+  default     = true
+  description = "Whether to use AmazonEC2RoleforSSM (will soon be deprecated) or AmazonSSMManagedInstanceCore policy"
+}