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Module: ec2-bastion-server

Terraform module to define a generic Bastion host with parameterized user_data and support for AWS SSM Session Manager for remote access with IAM authentication.

Variables​

Required Variables​

subnets (list(string)) required

AWS subnet IDs

vpc_id (string) required

VPC ID

Optional Variables​

ami (string) optional

AMI to use for the instance. Setting this will ignore ami_filter and ami_owners.


Default value: null

ami_filter (map(list(string))) optional

List of maps used to create the AMI filter for the action runner AMI.


Default value:

{
  "name": [
    "amzn2-ami-hvm-2.*-x86_64-ebs"
  ]
}
ami_owners (list(string)) optional

The list of owners used to select the AMI of action runner instances.


Default value:

[
  "amazon"
]
assign_eip_address (bool) optional

Assign an Elastic IP address to the instance


Default value: true

associate_public_ip_address (bool) optional

Whether to associate a public IP to the instance.


Default value: false

disable_api_termination (bool) optional

Enable EC2 Instance Termination Protection


Default value: false

ebs_block_device_encrypted (bool) optional

Whether to encrypt the EBS block device


Default value: true

ebs_block_device_volume_size (number) optional

The volume size (in GiB) to provision for the EBS block device. Creation skipped if size is 0


Default value: 0

ebs_delete_on_termination (bool) optional

Whether the EBS volume should be destroyed on instance termination


Default value: true

ebs_device_name (string) optional

The name of the EBS block device to mount on the instance


Default value: "/dev/sdh"

ebs_snapshot_id (string) optional

The snapshot id to use for the EBS block device


Default value: ""

host_name (string) optional

The Bastion hostname created in Route53


Default value: "bastion"

instance_profile (string) optional

A pre-defined profile to attach to the instance (default is to build our own)


Default value: ""

instance_type (string) optional

Bastion instance type


Default value: "t2.micro"

key_name (string) optional

Key name


Default value: ""

metadata_http_endpoint_enabled (bool) optional

Whether the metadata service is available


Default value: true

metadata_http_put_response_hop_limit (number) optional

The desired HTTP PUT response hop limit (between 1 and 64) for instance metadata requests.


Default value: 1

metadata_http_tokens_required (bool) optional

Whether or not the metadata service requires session tokens, also referred to as Instance Metadata Service Version 2.


Default value: true

monitoring (bool) optional

Launched EC2 instance will have detailed monitoring enabled


Default value: true

root_block_device_encrypted (bool) optional

Whether to encrypt the root block device


Default value: true

root_block_device_volume_size (number) optional

The volume size (in GiB) to provision for the root block device. It cannot be smaller than the AMI it refers to.


Default value: 8

security_group_description (string) optional

The Security Group description.


Default value: "Bastion host security group"

security_group_enabled (bool) optional

Whether to create default Security Group for bastion host.


Default value: true

security_group_rules (list(any)) optional

A list of maps of Security Group rules.
The values of map is fully complated with aws_security_group_rule resource.
To get more info see https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/security_group_rule .



Default value:

[
  {
    "cidr_blocks": [
      "0.0.0.0/0"
    ],
    "description": "Allow all outbound traffic",
    "from_port": 0,
    "protocol": -1,
    "to_port": 0,
    "type": "egress"
  },
  {
    "cidr_blocks": [
      "0.0.0.0/0"
    ],
    "description": "Allow all inbound to SSH",
    "from_port": 22,
    "protocol": "tcp",
    "to_port": 22,
    "type": "ingress"
  }
]
security_group_use_name_prefix (bool) optional

Whether to create a default Security Group with unique name beginning with the normalized prefix.


Default value: false

security_groups (list(string)) optional

A list of Security Group IDs to associate with bastion host.


Default value: [ ]

ssh_user (string) optional

Default SSH user for this AMI. e.g. ec2-user for Amazon Linux and ubuntu for Ubuntu systems


Default value: "ec2-user"

ssm_enabled (bool) optional

Enable SSM Agent on Host.


Default value: true

user_data (list(string)) optional

User data content. Will be ignored if user_data_base64 is set


Default value: [ ]

user_data_base64 (string) optional

The Base64-encoded user data to provide when launching the instances. If this is set then user_data will not be used.


Default value: ""

user_data_template (string) optional

User Data template to use for provisioning EC2 Bastion Host


Default value: "user_data/amazon-linux.sh"

zone_id (string) optional

Route53 DNS Zone ID


Default value: ""

Context Variables​

The following variables are defined in the context.tf file of this module and part of the terraform-null-label pattern.

additional_tag_map (map(string)) optional

Additional key-value pairs to add to each map in tags_as_list_of_maps. Not added to tags or id.
This is for some rare cases where resources want additional configuration of tags
and therefore take a list of maps with tag key, value, and additional configuration.


Required: No

Default value: { }

attributes (list(string)) optional

ID element. Additional attributes (e.g. workers or cluster) to add to id,
in the order they appear in the list. New attributes are appended to the
end of the list. The elements of the list are joined by the delimiter
and treated as a single ID element.


Required: No

Default value: [ ]

context (any) optional

Single object for setting entire context at once.
See description of individual variables for details.
Leave string and numeric variables as null to use default value.
Individual variable settings (non-null) override settings in context object,
except for attributes, tags, and additional_tag_map, which are merged.


Required: No

Default value:

{
  "additional_tag_map": {},
  "attributes": [],
  "delimiter": null,
  "descriptor_formats": {},
  "enabled": true,
  "environment": null,
  "id_length_limit": null,
  "label_key_case": null,
  "label_order": [],
  "label_value_case": null,
  "labels_as_tags": [
    "unset"
  ],
  "name": null,
  "namespace": null,
  "regex_replace_chars": null,
  "stage": null,
  "tags": {},
  "tenant": null
}
delimiter (string) optional

Delimiter to be used between ID elements.
Defaults to - (hyphen). Set to "" to use no delimiter at all.


Required: No

Default value: null

descriptor_formats (any) optional

Describe additional descriptors to be output in the descriptors output map.
Map of maps. Keys are names of descriptors. Values are maps of the form
\{<br/> format = string<br/> labels = list(string)<br/> \}
(Type is any so the map values can later be enhanced to provide additional options.)
format is a Terraform format string to be passed to the format() function.
labels is a list of labels, in order, to pass to format() function.
Label values will be normalized before being passed to format() so they will be
identical to how they appear in id.
Default is {} (descriptors output will be empty).


Required: No

Default value: { }

enabled (bool) optional

Set to false to prevent the module from creating any resources
Required: No

Default value: null

environment (string) optional

ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'
Required: No

Default value: null

id_length_limit (number) optional

Limit id to this many characters (minimum 6).
Set to 0 for unlimited length.
Set to null for keep the existing setting, which defaults to 0.
Does not affect id_full.


Required: No

Default value: null

label_key_case (string) optional

Controls the letter case of the tags keys (label names) for tags generated by this module.
Does not affect keys of tags passed in via the tags input.
Possible values: lower, title, upper.
Default value: title.


Required: No

Default value: null

label_order (list(string)) optional

The order in which the labels (ID elements) appear in the id.
Defaults to ["namespace", "environment", "stage", "name", "attributes"].
You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present.


Required: No

Default value: null

label_value_case (string) optional

Controls the letter case of ID elements (labels) as included in id,
set as tag values, and output by this module individually.
Does not affect values of tags passed in via the tags input.
Possible values: lower, title, upper and none (no transformation).
Set this to title and set delimiter to "" to yield Pascal Case IDs.
Default value: lower.


Required: No

Default value: null

labels_as_tags (set(string)) optional

Set of labels (ID elements) to include as tags in the tags output.
Default is to include all labels.
Tags with empty values will not be included in the tags output.
Set to [] to suppress all generated tags.
Notes:
The value of the name tag, if included, will be the id, not the name.
Unlike other null-label inputs, the initial setting of labels_as_tags cannot be
changed in later chained modules. Attempts to change it will be silently ignored.


Required: No

Default value:

[
  "default"
]
name (string) optional

ID element. Usually the component or solution name, e.g. 'app' or 'jenkins'.
This is the only ID element not also included as a tag.
The "name" tag is set to the full id string. There is no tag with the value of the name input.


Required: No

Default value: null

namespace (string) optional

ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique
Required: No

Default value: null

regex_replace_chars (string) optional

Terraform regular expression (regex) string.
Characters matching the regex will be removed from the ID elements.
If not set, "/[^a-zA-Z0-9-]/" is used to remove all characters other than hyphens, letters and digits.


Required: No

Default value: null

stage (string) optional

ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'
Required: No

Default value: null

tags (map(string)) optional

Additional tags (e.g. {'BusinessUnit': 'XYZ'}).
Neither the tag keys nor the tag values will be modified by this module.


Required: No

Default value: { }

tenant (string) optional

ID element (Rarely used, not included by default). A customer identifier, indicating who this instance of a resource is for
Required: No

Default value: null

Outputs​

arn

ARN of the instance

hostname

DNS hostname

id

Disambiguated ID of the instance

instance_id

Instance ID

name

Instance name

private_dns

Private DNS of instance

private_ip

Private IP of the instance

public_dns

Public DNS of instance (or DNS of EIP)

public_ip

Public IP of the instance (or EIP)

role

Name of AWS IAM Role associated with the instance

security_group_arn

Bastion host Security Group ARN

security_group_id

Bastion host Security Group ID

security_group_ids

IDs on the AWS Security Groups associated with the instance

security_group_name

Bastion host Security Group name

ssh_user

SSH user

Dependencies​

Requirements​

  • terraform, version: >= 0.13.0
  • aws, version: >= 2.55

Providers​

  • aws, version: >= 2.55

Modules​

NameVersionSourceDescription
dns0.12.2cloudposse/route53-cluster-hostname/awsn/a
security_group0.3.3cloudposse/security-group/awsn/a
this0.25.0cloudposse/label/nulln/a

Resources​

The following resources are used by this module:

Data Sources​

The following data sources are used by this module: