---
layout: "aws"
page_title: "AWS: aws_instance"
sidebar_current: "docs-aws-resource-instance"
description: |-
  Provides an EC2 instance resource. This allows instances to be created, updated, and deleted. Instances also support provisioning.
---

# aws\_instance

Provides an EC2 instance resource. This allows instances to be created, updated,
and deleted. Instances also support [provisioning](/docs/provisioners/index.html).

## Example Usage

```
# Create a new instance of the ami-1234 on an m1.small node
# with an AWS Tag naming it "HelloWorld"
resource "aws_instance" "web" {
    ami = "ami-1234"
    instance_type = "m1.small"
    tags {
        Name = "HelloWorld"
    }
}
```

## Argument Reference

The following arguments are supported:

* `ami` - (Required) The AMI to use for the instance.
* `availability_zone` - (Optional) The AZ to start the instance in.
* `ebs_optimized` - (Optional) If true, the launched EC2 instance will be
     EBS-optimized.
* `instance_type` - (Required) The type of instance to start
* `key_name` - (Optional) The key name to use for the instance.
* `security_groups` - (Optional) A list of security group IDs or names to associate with.
   If you are within a non-default VPC, you'll need to use the security group ID. Otherwise,
   for EC2 and the default VPC, use the security group name.
* `subnet_id` - (Optional) The VPC Subnet ID to launch in.
* `associate_public_ip_address` - (Optional) Associate a public ip address with an instance in a VPC.
* `private_ip` - (Optional) Private IP address to associate with the
     instance in a VPC.
* `source_dest_check` - (Optional) Controls if traffic is routed to the instance when
  the destination address does not match the instance. Used for NAT or VPNs. Defaults true.
* `user_data` - (Optional) The user data to provide when launching the instance.
* `iam_instance_profile` - (Optional) The IAM Instance Profile to
  launch the instance with.
* `tags` - (Optional) A mapping of tags to assign to the resource.
* `root_block_device` - (Optional) Customize details about the root block
  device of the instance. See [Block Devices](#block-devices) below for details.
* `ebs_block_device` - (Optional) Additional EBS block devices to attach to the
  instance.  See [Block Devices](#block-devices) below for details.
* `ephemeral_block_device` - (Optional) Customize Ephemeral (also known as
  "Instance Store") volumes on the instance. See [Block Devices](#block-devices) below for details.


<a id="block-devices"></a>
## Block devices

Each of the `*_block_device` attributes controls a portion of the AWS
Instance's "Block Device Mapping". It's a good idea to familiarize yourself with [AWS's Block Device
Mapping docs](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html)
to understand the implications of using these attributes.

The `root_block_device` mapping supports the following:

* `volume_type` - (Optional) The type of volume. Can be `"standard"`, `"gp2"`,
  or `"io1"`. (Default: `"standard"`).
* `volume_size` - (Optional) The size of the volume in gigabytes.
* `iops` - (Optional) The amount of provisioned
  [IOPS](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-io-characteristics.html).
  This must be set with a `volume_type` of `"io1"`.
* `delete_on_termination` - (Optional) Whether the volume should be destroyed
  on instance termination (Default: `true`).

Modifying any of the `root_block_device` settings requires resource
replacement.

Each `ebs_block_device` supports the following:

* `device_name` - The name of the device to mount.
* `snapshot_id` - (Optional) The Snapshot ID to mount.
* `volume_type` - (Optional) The type of volume. Can be `"standard"`, `"gp2"`,
  or `"io1"`. (Default: `"standard"`).
* `volume_size` - (Optional) The size of the volume in gigabytes.
* `iops` - (Optional) The amount of provisioned
  [IOPS](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-io-characteristics.html).
  This must be set with a `volume_type` of `"io1"`.
* `delete_on_termination` - (Optional) Whether the volume should be destroyed
  on instance termination (Default: `true`).
* `encrypted` - (Optional) Enables [EBS
  encryption](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html)
  on the volume (Default: `false`).

Modifying any `ebs_block_device` currently requires resource replacement.

Each `ephemeral_block_device` supports the following:

* `device_name` - The name of the block device to mount on the instance.
* `virtual_name` - The [Instance Store Device
  Name](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/InstanceStorage.html#InstanceStoreDeviceNames)
  (e.g. `"ephemeral0"`)

Each AWS Instance type has a different set of Instance Store block devices
available for attachment. AWS [publishes a
list](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/InstanceStorage.html#StorageOnInstanceTypes)
of which ephemeral devices are available on each type. The devices are always
identified by the `virtual_name` in the format `"ephemeral{0..N}"`.


~> **NOTE:** Because AWS [does not expose Instance Store mapping
details](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html#bdm-instance-metadata)
via an externally accessible API, `ephemeral_block_device` configuration may
only be applied at instance creation time, and changes to configuration of
existing resources cannot be detected by Terraform. Updates to Instance Store
block device configuration can be manually triggered by using the [`taint`
command](/docs/commands/taint.html).


## Attributes Reference

The following attributes are exported:

* `id` - The instance ID.
* `availability_zone` - The availability zone of the instance.
* `key_name` - The key name of the instance
* `private_dns` - The Private DNS name of the instance
* `private_ip` - The private IP address.
* `public_dns` - The public DNS name of the instance
* `public_ip` - The public IP address.
* `security_groups` - The associated security groups.
* `subnet_id` - The VPC subnet ID.