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.

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Makefile Targets

Available targets:

  help                                Help screen
  help/all                            Display help for all targets
  help/short                          This help short screen
  lint                                Lint terraform code

Requirements

Name	Version
terraform	>= 0.13.0
aws	>= 2.55

Providers

Name	Version
aws	>= 2.55

Modules

Name	Source	Version
dns	cloudposse/route53-cluster-hostname/aws	0.12.2
security_group	cloudposse/security-group/aws	0.3.3
this	cloudposse/label/null	0.25.0

Resources

Name	Type
aws_eip.default	resource
aws_iam_instance_profile.default	resource
aws_iam_role.default	resource
aws_iam_role_policy.main	resource
aws_instance.default	resource
aws_ami.default	data source
aws_iam_policy_document.default	data source
aws_iam_policy_document.main	data source
aws_region.default	data source
aws_route53_zone.domain	data source

Inputs

Name	Description	Type	Default	Required
additional_tag_map	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.	map(string)	{}	no
ami	AMI to use for the instance. Setting this will ignore ami_filter and ami_owners.	string	null	no
ami_filter	List of maps used to create the AMI filter for the action runner AMI.	map(list(string))	{ "name": [ "amzn2-ami-hvm-2.*-x86_64-ebs" ] }	no
ami_owners	The list of owners used to select the AMI of action runner instances.	list(string)	[ "amazon" ]	no
assign_eip_address	Assign an Elastic IP address to the instance	bool	true	no
associate_public_ip_address	Whether to associate a public IP to the instance.	bool	false	no
attributes	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.	list(string)	[]	no
context	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.	any	{ "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 }	no
delimiter	Delimiter to be used between ID elements. Defaults to - (hyphen). Set to "" to use no delimiter at all.	string	null	no
descriptor_formats	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).	any	{}	no
disable_api_termination	Enable EC2 Instance Termination Protection	bool	false	no
ebs_block_device_encrypted	Whether to encrypt the EBS block device	bool	true	no
ebs_block_device_volume_size	The volume size (in GiB) to provision for the EBS block device. Creation skipped if size is 0	number	0	no
ebs_delete_on_termination	Whether the EBS volume should be destroyed on instance termination	bool	true	no
ebs_device_name	The name of the EBS block device to mount on the instance	string	"/dev/sdh"	no
enabled	Set to false to prevent the module from creating any resources	bool	null	no
environment	ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'	string	null	no
host_name	The Bastion hostname created in Route53	string	"bastion"	no
id_length_limit	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.	number	null	no
instance_profile	A pre-defined profile to attach to the instance (default is to build our own)	string	""	no
instance_type	Bastion instance type	string	"t2.micro"	no
key_name	Key name	string	""	no
label_key_case	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.	string	null	no
label_order	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.	list(string)	null	no
label_value_case	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.	string	null	no
labels_as_tags	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.	set(string)	[ "default" ]	no
metadata_http_endpoint_enabled	Whether the metadata service is available	bool	true	no
metadata_http_put_response_hop_limit	The desired HTTP PUT response hop limit (between 1 and 64) for instance metadata requests.	number	1	no
metadata_http_tokens_required	Whether or not the metadata service requires session tokens, also referred to as Instance Metadata Service Version 2.	bool	true	no
monitoring	Launched EC2 instance will have detailed monitoring enabled	bool	true	no
name	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.	string	null	no
namespace	ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique	string	null	no
regex_replace_chars	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.	string	null	no
root_block_device_encrypted	Whether to encrypt the root block device	bool	true	no
root_block_device_volume_size	The volume size (in GiB) to provision for the root block device. It cannot be smaller than the AMI it refers to.	number	8	no
security_group_description	The Security Group description.	string	"Bastion host security group"	no
security_group_enabled	Whether to create default Security Group for bastion host.	bool	true	no
security_group_rules	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 .	list(any)	[ { "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" } ]	no
security_group_use_name_prefix	Whether to create a default Security Group with unique name beginning with the normalized prefix.	bool	false	no
security_groups	A list of Security Group IDs to associate with bastion host.	list(string)	[]	no
ssh_user	Default SSH user for this AMI. e.g. ec2-user for Amazon Linux and ubuntu for Ubuntu systems	string	"ec2-user"	no
ssm_enabled	Enable SSM Agent on Host.	bool	true	no
stage	ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'	string	null	no
subnets	AWS subnet IDs	list(string)	n/a	yes
tags	Additional tags (e.g. {'BusinessUnit': 'XYZ'}). Neither the tag keys nor the tag values will be modified by this module.	map(string)	{}	no
tenant	ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for	string	null	no
user_data	User data content. Will be ignored if user_data_base64 is set	list(string)	[]	no
user_data_base64	The Base64-encoded user data to provide when launching the instances. If this is set then user_data will not be used.	string	""	no
user_data_template	User Data template to use for provisioning EC2 Bastion Host	string	"user_data/amazon-linux.sh"	no
vpc_id	VPC ID	string	n/a	yes
zone_id	Route53 DNS Zone ID	string	""	no

Outputs

Name	Description
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

Related Projects

Check out these related projects.

• bastion - 🔒Secure Bastion implemented as Docker Container running Alpine Linux with Google Authenticator & DUO MFA support
• terraform-aws-ec2-instance - Terraform module for providing a general EC2 instance provisioned by Ansible
• terraform-aws-ec2-ami-backup - Terraform module for automatic & scheduled AMI creation

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License

Preamble to the Apache License, Version 2.0

Complete license is available in the LICENSE file.

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