Add AWS IAM PostgreSQL passwordless authentication support

locals.tf

@@ -38,6 +38,8 @@ locals {
 
   selected_database = (
     var.enable_aurora && var.db_use_mtls ? error("Both enable_aurora and db_use_mtls cannot be true.") :
+    var.enable_aurora && var.postgres_enable_iam_auth ? error("Both enable_aurora and postgres_enable_iam_auth cannot be true.") :
+    var.db_use_mtls && var.postgres_enable_iam_auth ? error("Both db_use_mtls and postgres_enable_iam_auth cannot be true.") :
     var.enable_aurora ? local.aurora_database :
     var.db_use_mtls ? local.mtls_database :
     var.enable_edb ? local.enterprise_db :

main.tf

@@ -161,21 +161,22 @@ module "database" {
   source = "./modules/database"
   count  = local.enable_database_module ? 1 : 0
 
-  db_size                      = var.db_size
-  db_backup_retention          = var.db_backup_retention
-  db_backup_window             = var.db_backup_window
-  db_name                      = var.db_name
-  db_parameters                = var.db_parameters
-  db_username                  = var.db_username
-  engine_version               = var.postgres_engine_version
-  friendly_name_prefix         = var.friendly_name_prefix
-  network_id                   = local.network_id
-  network_private_subnet_cidrs = var.network_private_subnet_cidrs
-  network_subnets_private      = local.network_private_subnets
-  tfe_instance_sg              = module.vm.tfe_instance_sg
-  kms_key_arn                  = local.kms_key_arn
-  allow_major_version_upgrade  = var.allow_major_version_upgrade
-  allow_multiple_azs           = var.allow_multiple_azs
+  db_size                            = var.db_size
+  db_backup_retention                = var.db_backup_retention
+  db_backup_window                   = var.db_backup_window
+  db_name                            = var.db_name
+  db_parameters                      = var.db_parameters
+  db_username                        = var.db_username
+  engine_version                     = var.postgres_engine_version
+  friendly_name_prefix               = var.friendly_name_prefix
+  network_id                         = local.network_id
+  network_private_subnet_cidrs       = var.network_private_subnet_cidrs
+  network_subnets_private            = local.network_private_subnets
+  tfe_instance_sg                    = module.vm.tfe_instance_sg
+  kms_key_arn                        = local.kms_key_arn
+  allow_major_version_upgrade        = var.allow_major_version_upgrade
+  allow_multiple_azs                 = var.allow_multiple_azs
+  enable_iam_database_authentication = var.postgres_enable_iam_auth && !var.postgres_use_password_auth
 }
 
 # -----------------------------------------------------------------------------
@@ -253,7 +254,7 @@ module "aurora_database" {
 # Docker Compose File Config for TFE on instance(s) using Flexible Deployment Options
 # ------------------------------------------------------------------------------------
 module "runtime_container_engine_config" {
-  source = "git::https://github.com/hashicorp/terraform-random-tfe-utility//modules/runtime_container_engine_config?ref=main"
+  source = "./modules/runtime_container_engine_config"
   count  = var.is_replicated_deployment ? 0 : 1
 
   tfe_license = var.hc_license
@@ -286,15 +287,17 @@ module "runtime_container_engine_config" {
   iact_time_limit      = var.iact_subnet_time_limit
   run_pipeline_image   = var.run_pipeline_image
 
-  database_name             = local.database.name
-  database_user             = local.database.username
-  database_password         = local.database.password
-  database_host             = local.database.endpoint
-  database_parameters       = local.database.parameters
-  database_use_mtls         = var.db_use_mtls
-  database_ca_cert_file     = "/etc/ssl/private/terraform-enterprise/postgres/ca.crt"
-  database_client_cert_file = "/etc/ssl/private/terraform-enterprise/postgres/cert.crt"
-  database_client_key_file  = "/etc/ssl/private/terraform-enterprise/postgres/key.key"
+  database_name                     = local.database.name
+  database_user                     = local.database.username
+  database_password                 = local.database.password
+  database_host                     = local.database.endpoint
+  database_parameters               = local.database.parameters
+  database_use_mtls                 = var.db_use_mtls
+  database_ca_cert_file             = "/etc/ssl/private/terraform-enterprise/postgres/ca.crt"
+  database_client_cert_file         = "/etc/ssl/private/terraform-enterprise/postgres/cert.crt"
+  database_client_key_file          = "/etc/ssl/private/terraform-enterprise/postgres/key.key"
+  database_passwordless_aws_use_iam = var.postgres_enable_iam_auth && !var.postgres_use_password_auth
+  database_passwordless_aws_region  = var.postgres_enable_iam_auth && !var.postgres_use_password_auth ? data.aws_region.current.name : ""
 
   explorer_database_name       = local.explorer_database.name
   explorer_database_user       = local.explorer_database.username
@@ -343,7 +346,7 @@ module "runtime_container_engine_config" {
 # AWS cloud init used to install and configure TFE on instance(s) using Flexible Deployment Options
 # --------------------------------------------------------------------------------------------------
 module "tfe_init_fdo" {
-  source = "git::https://github.com/hashicorp/terraform-random-tfe-utility//modules/tfe_init?ref=main"
+  source = "./modules/tfe_init"
   count  = var.is_replicated_deployment ? 0 : 1
 
   cloud             = "aws"
@@ -388,7 +391,7 @@ module "tfe_init_fdo" {
 # TFE and Replicated settings to pass to the tfe_init_replicated module for replicated deployment
 # --------------------------------------------------------------------------------------------
 module "settings" {
-  source = "git::https://github.com/hashicorp/terraform-random-tfe-utility//modules/settings?ref=main"
+  source = "./modules/settings"
   count  = var.is_replicated_deployment ? 1 : 0
 
   # TFE Base Configuration
@@ -450,7 +453,7 @@ module "settings" {
 # AWS user data / cloud init used to install and configure TFE on instance(s)
 # -----------------------------------------------------------------------------
 module "tfe_init_replicated" {
-  source = "git::https://github.com/hashicorp/terraform-random-tfe-utility//modules/tfe_init_replicated?ref=main"
+  source = "./modules/tfe_init_replicated"
   count  = var.is_replicated_deployment ? 1 : 0
 
   # TFE & Replicated Configuration data

modules/database/main.tf

@@ -83,4 +83,7 @@ resource "aws_db_instance" "postgresql" {
   kms_key_id             = var.kms_key_arn
   storage_type           = "gp2"
   vpc_security_group_ids = [aws_security_group.postgresql.id]
+
+  # Enable IAM database authentication if requested
+  iam_database_authentication_enabled = var.enable_iam_database_authentication
 }

modules/database/variables.tf

@@ -77,3 +77,9 @@ variable "allow_multiple_azs" {
   description = "Determine Amazon RDS Postgres deployment strategy."
   default     = true
 }
+
+variable "enable_iam_database_authentication" {
+  type        = bool
+  description = "Enable IAM database authentication for the RDS instance."
+  default     = false
+}

modules/postgres-passwordless/data.tf

@@ -0,0 +1,23 @@
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: MPL-2.0
+
+data "aws_ami" "ubuntu" {
+  most_recent = true
+
+  filter {
+    name   = "name"
+    values = ["ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-*"]
+  }
+
+  filter {
+    name   = "virtualization-type"
+    values = ["hvm"]
+  }
+
+  owners = ["099720109477"] # Canonical
+}
+
+data "aws_route53_zone" "postgres_zone" {
+  name         = var.domain_name
+  private_zone = false
+}

modules/postgres-passwordless/files/fetch_cert_and_start_server.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: MPL-2.0
+
+set -eu pipefail
+
+apt-get update -y && apt-get install -y docker.io postgresql-client openssl unzip jq
+systemctl enable --now docker
+usermod -aG docker ubuntu
+
+curl -sS --noproxy '*' "https://awscli.amazonaws.com/awscli-exe-linux-$(uname -m | grep -q 'arm\|aarch' && echo 'aarch64' || echo 'x86_64').zip" -o "awscliv2.zip" > /dev/null 2>&1
+unzip -q awscliv2.zip > /dev/null 2>&1
+./aws/install > /dev/null 2>&1
+rm -rf aws awscliv2.zip > /dev/null 2>&1
+
+# For passwordless postgres, we start with basic configuration
+# IAM authentication will be handled at the RDS level
+docker run -d \
+  --name postgres \
+  -p 5432:5432 \
+  -e POSTGRES_USER="$POSTGRES_USER" \
+  -e POSTGRES_PASSWORD="$POSTGRES_PASSWORD" \
+  -e POSTGRES_DB="$POSTGRES_DB" \
+  postgres:16
+
+# Wait until PostgreSQL is up
+echo "Waiting for PostgreSQL to become ready..."
+timeout=180
+start=$(date +%s)
+while ! docker exec postgres pg_isready -U "$POSTGRES_USER" >/dev/null 2>&1; do
+  sleep 1
+  [[ $(( $(date +%s) - start )) -gt $timeout ]] && echo "Timeout waiting for PostgreSQL" && docker logs postgres && exit 1
+done
+
+echo "PostgreSQL with passwordless authentication is fully up and running."

modules/postgres-passwordless/main.tf

@@ -0,0 +1,113 @@
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: MPL-2.0
+
+# This module provisions a PostgreSQL instance with passwordless authentication (IAM or similar)
+# Adapted from database-mtls module, but without client certs/keys and with passwordless config
+
+resource "random_string" "postgres_db_password" {
+  length           = 128
+  special          = true
+  override_special = "#$%&*"
+}
+
+resource "aws_route53_record" "postgres_db_dns" {
+  zone_id = data.aws_route53_zone.postgres_zone.zone_id
+  name    = "${var.friendly_name_prefix}-postgres-passwordless"
+  type    = "A"
+  ttl     = 300
+
+  records = [aws_instance.postgres_db_instance.public_ip]
+}
+
+resource "aws_security_group" "postgres_db_sg" {
+  description = "The security group of the PostgreSQL deployment for TFE."
+  name        = "${var.friendly_name_prefix}-postgres-passwordless"
+  vpc_id      = var.network_id
+}
+
+resource "aws_security_group_rule" "postgres_db_ingress" {
+  security_group_id = aws_security_group.postgres_db_sg.id
+  type              = "ingress"
+  from_port         = 5432
+  to_port           = 5432
+  protocol          = "tcp"
+  cidr_blocks       = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "postgres_db_ssh_ingress" {
+  security_group_id = aws_security_group.postgres_db_sg.id
+  type              = "ingress"
+  from_port         = 22
+  to_port           = 22
+  protocol          = "tcp"
+  cidr_blocks       = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "postgres_db_egress" {
+  security_group_id = aws_security_group.postgres_db_sg.id
+  type              = "egress"
+  from_port         = 0
+  to_port           = 0
+  protocol          = "-1"
+  cidr_blocks       = ["0.0.0.0/0"]
+}
+
+resource "aws_instance" "postgres_db_instance" {
+  ami                         = data.aws_ami.ubuntu.id
+  instance_type               = "m5.xlarge"
+  associate_public_ip_address = true
+  vpc_security_group_ids      = [aws_security_group.postgres_db_sg.id]
+  iam_instance_profile        = var.aws_iam_instance_profile
+  key_name                    = aws_key_pair.ec2_key.key_name
+  subnet_id                   = var.network_public_subnets[0]
+  root_block_device {
+    volume_type           = "gp3"
+    volume_size           = 100
+    delete_on_termination = true
+    encrypted             = true
+  }
+
+  tags = {
+    Name = "Terraform-Postgres-Passwordless"
+  }
+}
+
+resource "local_file" "postgres_db_private_key" {
+  content         = tls_private_key.postgres_db_ssh_key.private_key_pem
+  filename        = "${path.module}/${var.friendly_name_prefix}-ec2-postgres-key.pem"
+  file_permission = "0600"
+}
+
+resource "tls_private_key" "postgres_db_ssh_key" {
+  algorithm = "RSA"
+  rsa_bits  = 4096
+}
+
+resource "aws_key_pair" "ec2_key" {
+  key_name   = "${var.friendly_name_prefix}-ec2-postgres-key"
+  public_key = tls_private_key.postgres_db_ssh_key.public_key_openssh
+}
+
+resource "null_resource" "postgres_db_server_start" {
+  depends_on = [aws_route53_record.postgres_db_dns]
+
+  connection {
+    type        = "ssh"
+    user        = "ubuntu"
+    private_key = tls_private_key.postgres_db_ssh_key.private_key_pem
+    host        = aws_route53_record.postgres_db_dns.fqdn
+  }
+
+  provisioner "file" {
+    source      = "${path.module}/files/fetch_cert_and_start_server.sh"
+    destination = "/home/ubuntu/fetch_cert_and_start_server.sh"
+  }
+
+  provisioner "remote-exec" {
+    inline = [
+      "sleep 60",
+      "chmod +x /home/ubuntu/fetch_cert_and_start_server.sh",
+      "sudo POSTGRES_PASSWORD='${random_string.postgres_db_password.result}' POSTGRES_USER=${var.db_username} POSTGRES_DB=${var.db_name} /home/ubuntu/fetch_cert_and_start_server.sh"
+    ]
+  }
+}

modules/postgres-passwordless/outputs.tf

@@ -0,0 +1,45 @@
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: MPL-2.0
+
+output "endpoint" {
+  description = "The connection endpoint of the PostgreSQL instance in address:port format."
+  value       = aws_route53_record.postgres_db_dns.fqdn
+}
+
+output "name" {
+  description = "The name of the PostgreSQL instance."
+  value       = var.db_name
+}
+
+output "password" {
+  description = "The password of the main PostgreSQL user."
+  value       = random_string.postgres_db_password.result
+  sensitive   = true
+}
+
+output "username" {
+  description = "The name of the main PostgreSQL user."
+  value       = var.db_username
+}
+
+output "parameters" {
+  description = "PostgreSQL server parameters for the connection URI."
+  value       = var.db_parameters
+}
+
+# Legacy outputs for backward compatibility
+output "postgres_db_endpoint" {
+  description = "The endpoint of the PostgreSQL instance."
+  value       = aws_route53_record.postgres_db_dns.fqdn
+}
+
+output "postgres_db_sg_id" {
+  description = "The security group ID for the PostgreSQL instance."
+  value       = aws_security_group.postgres_db_sg.id
+}
+
+output "postgres_db_password" {
+  description = "The password for the PostgreSQL instance."
+  value       = random_string.postgres_db_password.result
+  sensitive   = true
+}

modules/postgres-passwordless/service_accounts/data.tf

@@ -0,0 +1,14 @@
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: MPL-2.0
+
+data "aws_iam_instance_profile" "existing_instance_profile" {
+  count = var.existing_iam_instance_profile_name != null ? 1 : 0
+
+  name = var.existing_iam_instance_profile_name
+}
+
+data "aws_iam_role" "existing_instance_role" {
+  count = var.existing_iam_instance_role_name != null ? 1 : 0
+
+  name = var.existing_iam_instance_role_name
+}

modules/postgres-passwordless/service_accounts/locals.tf

@@ -0,0 +1,7 @@
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: MPL-2.0
+
+locals {
+  iam_instance_role    = try(data.aws_iam_role.existing_instance_role[0], aws_iam_role.instance_role[0])
+  iam_instance_profile = try(data.aws_iam_instance_profile.existing_instance_profile[0], aws_iam_instance_profile.postgres_passwordless[0])
+}