diff --git a/modules/aws/ami/README.md b/modules/aws/ami/README.md
new file mode 100644
index 00000000000..61f43f421e8
--- /dev/null
+++ b/modules/aws/ami/README.md
@@ -0,0 +1,27 @@
+# Container Linux AMI Module
+
+This [Terraform][] [module][] supports `latest` versions for [Container Linux][container-linux] release channels and returns an appropriate [AMI][].
+
+## Example
+
+From the module directory:
+
+```console
+$ terraform init
+$ terraform apply --var region=us-east-1
+$ terraform output id
+ami-ab6963d4
+$ terraform apply --var region=us-east-1 --var release_channel=alpha
+$ terraform output id
+ami-985953e7
+$ terraform apply --var region=us-east-2 --var release_channel=alpha --var release_version=1814.0.0
+$ terraform output id
+ami-c25f66a7
+```
+
+When you're done, clean up by removing the `.terraform` directory created by `init` and the `terraform.tfstate*` files created by `apply`.
+
+[AMI]: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AMIs.html
+[container-linux]: https://coreos.com/os/docs/latest/
+[module]: https://www.terraform.io/docs/modules/
+[Terraform]: https://www.terraform.io/
diff --git a/modules/aws/ami/main.tf b/modules/aws/ami/main.tf
new file mode 100644
index 00000000000..1593457145e
--- /dev/null
+++ b/modules/aws/ami/main.tf
@@ -0,0 +1,38 @@
+provider "aws" {
+  region  = "${var.region}"
+  version = "1.8.0"
+}
+
+locals {
+  ami_owner = "595879546273"
+  arn       = "aws"
+}
+
+module "container_linux" {
+  source = "../../container_linux"
+
+  release_channel = "${var.release_channel}"
+  release_version = "${var.release_version}"
+}
+
+data "aws_ami" "coreos_ami" {
+  filter {
+    name   = "name"
+    values = ["CoreOS-${var.release_channel}-${module.container_linux.version}-*"]
+  }
+
+  filter {
+    name   = "architecture"
+    values = ["x86_64"]
+  }
+
+  filter {
+    name   = "virtualization-type"
+    values = ["hvm"]
+  }
+
+  filter {
+    name   = "owner-id"
+    values = ["${local.ami_owner}"]
+  }
+}
diff --git a/modules/aws/ami/outputs.tf b/modules/aws/ami/outputs.tf
new file mode 100644
index 00000000000..b6ed23ce383
--- /dev/null
+++ b/modules/aws/ami/outputs.tf
@@ -0,0 +1,4 @@
+output "id" {
+  value       = "${data.aws_ami.coreos_ami.image_id}"
+  description = "The selected CoreOS Container Linux AMI ID."
+}
diff --git a/modules/aws/ami/variables.tf b/modules/aws/ami/variables.tf
new file mode 100644
index 00000000000..5b84b10cdd5
--- /dev/null
+++ b/modules/aws/ami/variables.tf
@@ -0,0 +1,30 @@
+variable "region" {
+  type = "string"
+
+  description = <<EOF
+This is the AWS region.
+It is passed through to the Terraform aws provider: https://www.terraform.io/docs/providers/aws/#region
+EOF
+}
+
+variable "release_channel" {
+  type    = "string"
+  default = "stable"
+
+  description = <<EOF
+The Container Linux update channel.
+
+Examples: `stable`, `beta`, `alpha`
+EOF
+}
+
+variable "release_version" {
+  type    = "string"
+  default = "latest"
+
+  description = <<EOF
+The Container Linux version to use. Set to `latest` to select the latest available version for the selected update channel.
+
+Examples: `latest`, `1465.6.0`
+EOF
+}
diff --git a/modules/aws/etcd/README.md b/modules/aws/etcd/README.md
index 4b1ed7c0f67..4776ff2d9a0 100644
--- a/modules/aws/etcd/README.md
+++ b/modules/aws/etcd/README.md
@@ -7,10 +7,14 @@ Read the [etcd recommended hardware guide][hardware] for best performance.
 ## Example
 
 ```hcl
-provider "aws" {
+locals {
   region = "us-east-1"
 }
 
+provider "aws" {
+  region = "${local.region}"
+}
+
 resource "aws_s3_bucket" "etcd_ignition" {
 }
 
@@ -50,6 +54,7 @@ module "etcd" {
   cluster_id     = "123"
   cluster_name   = "my-cluster"
   instance_count = "3"
+  region         = "${local.region}"
   s3_bucket      = "${aws_s3_bucket.etcd_ignition.id}"
   sg_ids         = ["${aws_security_group.etcd.id}"]
   subnets        = ["${aws_subnet.example.id}"]
diff --git a/modules/aws/etcd/nodes.tf b/modules/aws/etcd/nodes.tf
index 99429f67e94..96be2cc39d6 100644
--- a/modules/aws/etcd/nodes.tf
+++ b/modules/aws/etcd/nodes.tf
@@ -1,37 +1,15 @@
 locals {
-  ami_owner = "595879546273"
-  arn       = "aws"
+  arn = "aws"
 }
 
-module "container_linux" {
-  source = "../../container_linux"
+module "ami" {
+  source = "../ami"
 
+  region          = "${var.region}"
   release_channel = "${var.container_linux_channel}"
   release_version = "${var.container_linux_version}"
 }
 
-data "aws_ami" "coreos_ami" {
-  filter {
-    name   = "name"
-    values = ["CoreOS-${var.container_linux_channel}-${module.container_linux.version}-*"]
-  }
-
-  filter {
-    name   = "architecture"
-    values = ["x86_64"]
-  }
-
-  filter {
-    name   = "virtualization-type"
-    values = ["hvm"]
-  }
-
-  filter {
-    name   = "owner-id"
-    values = ["${local.ami_owner}"]
-  }
-}
-
 resource "aws_iam_instance_profile" "etcd" {
   name = "${var.cluster_name}-etcd-profile"
 
@@ -106,7 +84,7 @@ EOF
 
 resource "aws_instance" "etcd_node" {
   count = "${var.instance_count}"
-  ami   = "${coalesce(var.ec2_ami, data.aws_ami.coreos_ami.image_id)}"
+  ami   = "${coalesce(var.ec2_ami, module.ami.id)}"
 
   iam_instance_profile   = "${aws_iam_instance_profile.etcd.name}"
   instance_type          = "${var.ec2_type}"
diff --git a/modules/aws/etcd/variables.tf b/modules/aws/etcd/variables.tf
index 60ddda55dfc..f4aae123447 100644
--- a/modules/aws/etcd/variables.tf
+++ b/modules/aws/etcd/variables.tf
@@ -24,6 +24,15 @@ variable "instance_count" {
   default = "3"
 }
 
+variable "region" {
+  type = "string"
+
+  description = <<EOF
+This is the AWS region.
+It is passed through to the Terraform aws provider: https://www.terraform.io/docs/providers/aws/#region
+EOF
+}
+
 variable "ssh_key" {
   type    = "string"
   default = ""
diff --git a/modules/aws/master-asg/master.tf b/modules/aws/master-asg/master.tf
index aef72b9e850..0fadf1db1c8 100644
--- a/modules/aws/master-asg/master.tf
+++ b/modules/aws/master-asg/master.tf
@@ -1,28 +1,13 @@
 locals {
-  ami_owner = "595879546273"
-  arn       = "aws"
+  arn = "aws"
 }
 
-data "aws_ami" "coreos_ami" {
-  filter {
-    name   = "name"
-    values = ["CoreOS-${var.container_linux_channel}-${var.container_linux_version}-*"]
-  }
-
-  filter {
-    name   = "architecture"
-    values = ["x86_64"]
-  }
+module "ami" {
+  source = "../ami"
 
-  filter {
-    name   = "virtualization-type"
-    values = ["hvm"]
-  }
-
-  filter {
-    name   = "owner-id"
-    values = ["${local.ami_owner}"]
-  }
+  region          = "${var.region}"
+  release_channel = "${var.container_linux_channel}"
+  release_version = "${var.container_linux_version}"
 }
 
 resource "aws_autoscaling_group" "masters" {
@@ -61,7 +46,7 @@ resource "aws_autoscaling_group" "masters" {
 
 resource "aws_launch_configuration" "master_conf" {
   instance_type               = "${var.ec2_type}"
-  image_id                    = "${coalesce(var.ec2_ami, data.aws_ami.coreos_ami.image_id)}"
+  image_id                    = "${coalesce(var.ec2_ami, module.ami.id)}"
   name_prefix                 = "${var.cluster_name}-master-"
   key_name                    = "${var.ssh_key}"
   security_groups             = ["${var.master_sg_ids}"]
diff --git a/modules/aws/master-asg/variables.tf b/modules/aws/master-asg/variables.tf
index 35b325a2851..f0b9314fbe3 100644
--- a/modules/aws/master-asg/variables.tf
+++ b/modules/aws/master-asg/variables.tf
@@ -76,6 +76,15 @@ variable "aws_lbs" {
   default     = []
 }
 
+variable "region" {
+  type = "string"
+
+  description = <<EOF
+This is the AWS region.
+It is passed through to the Terraform aws provider: https://www.terraform.io/docs/providers/aws/#region
+EOF
+}
+
 variable "root_volume_iops" {
   type        = "string"
   default     = "100"
diff --git a/modules/aws/worker-asg/variables.tf b/modules/aws/worker-asg/variables.tf
index 9ef40767344..2883de0dfcc 100644
--- a/modules/aws/worker-asg/variables.tf
+++ b/modules/aws/worker-asg/variables.tf
@@ -58,6 +58,15 @@ variable "autoscaling_group_extra_tags" {
   default     = []
 }
 
+variable "region" {
+  type = "string"
+
+  description = <<EOF
+This is the AWS region.
+It is passed through to the Terraform aws provider: https://www.terraform.io/docs/providers/aws/#region
+EOF
+}
+
 variable "root_volume_type" {
   type        = "string"
   description = "The type of volume for the root block device."
diff --git a/modules/aws/worker-asg/worker.tf b/modules/aws/worker-asg/worker.tf
index fa9540db501..ef415a44ae3 100644
--- a/modules/aws/worker-asg/worker.tf
+++ b/modules/aws/worker-asg/worker.tf
@@ -1,33 +1,18 @@
 locals {
-  ami_owner = "595879546273"
-  arn       = "aws"
+  arn = "aws"
 }
 
-data "aws_ami" "coreos_ami" {
-  filter {
-    name   = "name"
-    values = ["CoreOS-${var.container_linux_channel}-${var.container_linux_version}-*"]
-  }
-
-  filter {
-    name   = "architecture"
-    values = ["x86_64"]
-  }
+module "ami" {
+  source = "../ami"
 
-  filter {
-    name   = "virtualization-type"
-    values = ["hvm"]
-  }
-
-  filter {
-    name   = "owner-id"
-    values = ["${local.ami_owner}"]
-  }
+  region          = "${var.region}"
+  release_channel = "${var.container_linux_channel}"
+  release_version = "${var.container_linux_version}"
 }
 
 resource "aws_launch_configuration" "worker_conf" {
   instance_type        = "${var.ec2_type}"
-  image_id             = "${coalesce(var.ec2_ami, data.aws_ami.coreos_ami.image_id)}"
+  image_id             = "${coalesce(var.ec2_ami, module.ami.id)}"
   name_prefix          = "${var.cluster_name}-worker-"
   key_name             = "${var.ssh_key}"
   security_groups      = ["${var.sg_ids}"]
diff --git a/steps/etcd/aws/etcd.tf b/steps/etcd/aws/etcd.tf
index abb355292b0..a5d00792864 100644
--- a/steps/etcd/aws/etcd.tf
+++ b/steps/etcd/aws/etcd.tf
@@ -58,6 +58,7 @@ module "etcd" {
   ec2_type                = "${var.tectonic_aws_etcd_ec2_type}"
   extra_tags              = "${var.tectonic_aws_extra_tags}"
   instance_count          = "${length(data.template_file.etcd_hostname_list.*.id)}"
+  region                  = "${var.tectonic_aws_region}"
   root_volume_iops        = "${var.tectonic_aws_etcd_root_volume_iops}"
   root_volume_size        = "${var.tectonic_aws_etcd_root_volume_size}"
   root_volume_type        = "${var.tectonic_aws_etcd_root_volume_type}"
diff --git a/steps/joining_workers/aws/workers.tf b/steps/joining_workers/aws/workers.tf
index de29ed68004..b391f8bc0c5 100644
--- a/steps/joining_workers/aws/workers.tf
+++ b/steps/joining_workers/aws/workers.tf
@@ -28,6 +28,7 @@ module "workers" {
   extra_tags                   = "${var.tectonic_aws_extra_tags}"
   instance_count               = "${var.tectonic_worker_count}"
   load_balancers               = "${var.tectonic_aws_worker_load_balancers}"
+  region                       = "${var.tectonic_aws_region}"
   root_volume_iops             = "${var.tectonic_aws_worker_root_volume_iops}"
   root_volume_size             = "${var.tectonic_aws_worker_root_volume_size}"
   root_volume_type             = "${var.tectonic_aws_worker_root_volume_type}"
diff --git a/steps/masters/aws/main.tf b/steps/masters/aws/main.tf
index e30bc61f65b..ecd699ca8ad 100644
--- a/steps/masters/aws/main.tf
+++ b/steps/masters/aws/main.tf
@@ -39,6 +39,7 @@ module "masters" {
   master_sg_ids                = "${concat(var.tectonic_aws_master_extra_sg_ids, list(local.sg_id))}"
   private_endpoints            = "${local.private_endpoints}"
   public_endpoints             = "${local.public_endpoints}"
+  region                       = "${var.tectonic_aws_region}"
   root_volume_iops             = "${var.tectonic_aws_master_root_volume_iops}"
   root_volume_size             = "${var.tectonic_aws_master_root_volume_size}"
   root_volume_type             = "${var.tectonic_aws_master_root_volume_type}"