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Module: vpc-peering-multi-account

Terraform module to create a peering connection between any two VPCs existing in different AWS accounts.

This module supports performing this action from a 3rd account (e.g. a "root" account) by specifying the roles to assume for each member account.

IMPORTANT: AWS allows a multi-account VPC Peering Connection to be deleted from either the requester's or accepter's side. However, Terraform only allows the VPC Peering Connection to be deleted from the requester's side by removing the corresponding aws_vpc_peering_connection resource from your configuration. Read more about this on Terraform's documentation portal.

Screenshots

vpc-peering VPC Peering Connection in the AWS Web Console

Usage

IMPORTANT: Do not pin to master because there may be breaking changes between releases. Instead pin to the release tag (e.g. ?ref=tags/x.y.z) of one of our latest releases.

For a complete example, see examples/complete

module "vpc_peering_cross_account" {
source = "cloudposse/vpc-peering-multi-account/aws"
# Cloud Posse recommends pinning every module to a specific version
# version = "x.x.x"
namespace = "eg"
stage = "dev"
name = "cluster"

requester_aws_assume_role_arn = "arn:aws:iam::XXXXXXXX:role/cross-account-vpc-peering-test"
requester_region = "us-west-2"
requester_vpc_id = "vpc-xxxxxxxx"
requester_allow_remote_vpc_dns_resolution = true

accepter_aws_assume_role_arn = "arn:aws:iam::YYYYYYYY:role/cross-account-vpc-peering-test"
accepter_region = "us-east-1"
accepter_vpc_id = "vpc-yyyyyyyy"
accepter_allow_remote_vpc_dns_resolution = true
}

The arn:aws:iam::XXXXXXXX:role/cross-account-vpc-peering-test requester IAM Role should have the following Trust Policy:

Show Trust Policy
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::XXXXXXXX:root"
},
"Action": "sts:AssumeRole",
"Condition": {}
}
]
}

and the following IAM Policy attached to it:

NOTE: the policy specifies the permissions to create (with terraform plan/apply) and delete (with terraform destroy) all the required resources in the requester AWS account

Show IAM Policy
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ec2:CreateRoute",
"ec2:DeleteRoute"
],
"Resource": "arn:aws:ec2:*:XXXXXXXX:route-table/*"
},
{
"Effect": "Allow",
"Action": [
"ec2:DescribeVpcPeeringConnections",
"ec2:DescribeVpcs",
"ec2:ModifyVpcPeeringConnectionOptions",
"ec2:DescribeSubnets",
"ec2:DescribeVpcAttribute",
"ec2:DescribeRouteTables"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"ec2:AcceptVpcPeeringConnection",
"ec2:DeleteVpcPeeringConnection",
"ec2:CreateVpcPeeringConnection",
"ec2:RejectVpcPeeringConnection"
],
"Resource": [
"arn:aws:ec2:*:XXXXXXXX:vpc-peering-connection/*",
"arn:aws:ec2:*:XXXXXXXX:vpc/*"
]
},
{
"Effect": "Allow",
"Action": [
"ec2:DeleteTags",
"ec2:CreateTags"
],
"Resource": "arn:aws:ec2:*:XXXXXXXX:vpc-peering-connection/*"
}
]
}

where XXXXXXXX is the requester AWS account ID.


The arn:aws:iam::YYYYYYYY:role/cross-account-vpc-peering-test accepter IAM Role should have the following Trust Policy:

Show Trust Policy
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::XXXXXXXX:root"
},
"Action": "sts:AssumeRole",
"Condition": {}
}
]
}

NOTE: The accepter Trust Policy is the same as the requester Trust Policy since it defines who can assume the IAM Role. In the requester case, the requester account ID itself is the trusted entity. For the accepter, the Trust Policy specifies that the requester account ID XXXXXXXX can assume the role in the accepter AWS account YYYYYYYY.

and the following IAM Policy attached to it:

NOTE: the policy specifies the permissions to create (with terraform plan/apply) and delete (with terraform destroy) all the required resources in the accepter AWS account

Show IAM Policy
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ec2:CreateRoute",
"ec2:DeleteRoute"
],
"Resource": "arn:aws:ec2:*:YYYYYYYY:route-table/*"
},
{
"Effect": "Allow",
"Action": [
"ec2:DescribeVpcPeeringConnections",
"ec2:DescribeVpcs",
"ec2:ModifyVpcPeeringConnectionOptions",
"ec2:DescribeSubnets",
"ec2:DescribeVpcAttribute",
"ec2:DescribeRouteTables"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"ec2:AcceptVpcPeeringConnection",
"ec2:DeleteVpcPeeringConnection",
"ec2:CreateVpcPeeringConnection",
"ec2:RejectVpcPeeringConnection"
],
"Resource": [
"arn:aws:ec2:*:YYYYYYYY:vpc-peering-connection/*",
"arn:aws:ec2:*:YYYYYYYY:vpc/*"
]
},
{
"Effect": "Allow",
"Action": [
"ec2:DeleteTags",
"ec2:CreateTags"
],
"Resource": "arn:aws:ec2:*:YYYYYYYY:vpc-peering-connection/*"
}
]
}

where YYYYYYYY is the accepter AWS account ID.

For more information on IAM policies and permissions for VPC peering, see Creating and managing VPC peering connections.

Variables

Required Variables

accepter_region (string) required

Accepter AWS region

requester_aws_assume_role_arn (string) required

Requester AWS Assume Role ARN

requester_region (string) required

Requester AWS region

Optional Variables

accepter_allow_remote_vpc_dns_resolution (bool) optional

Allow accepter VPC to resolve public DNS hostnames to private IP addresses when queried from instances in the requester VPC


Default value: true

accepter_aws_access_key (string) optional

Access key id to use in accepter account


Default value: null

accepter_aws_assume_role_arn (string) optional

Accepter AWS Assume Role ARN


Default value: null

accepter_aws_profile (string) optional

Profile used to assume accepter_aws_assume_role_arn


Default value: ""

accepter_aws_secret_key (string) optional

Secret access key to use in accepter account


Default value: null

accepter_aws_token (string) optional

Session token for validating temporary credentials


Default value: null

accepter_enabled (bool) optional

Flag to enable/disable the accepter side of the peering connection


Default value: true

accepter_subnet_tags (map(string)) optional

Only add peer routes to accepter VPC route tables of subnets matching these tags


Default value: { }

accepter_vpc_id (string) optional

Accepter VPC ID filter


Default value: ""

accepter_vpc_tags (map(string)) optional

Accepter VPC Tags filter


Default value: { }

add_attribute_tag (bool) optional

If true will add additional attribute tag to the requester and accceptor resources


Default value: true

auto_accept (bool) optional

Automatically accept the peering


Default value: true

aws_route_create_timeout (string) optional

Time to wait for AWS route creation specifed as a Go Duration, e.g. 2m


Default value: "5m"

aws_route_delete_timeout (string) optional

Time to wait for AWS route deletion specifed as a Go Duration, e.g. 5m


Default value: "5m"

requester_allow_remote_vpc_dns_resolution (bool) optional

Allow requester VPC to resolve public DNS hostnames to private IP addresses when queried from instances in the accepter VPC


Default value: true

requester_aws_access_key (string) optional

Access key id to use in requester account


Default value: null

requester_aws_profile (string) optional

Profile used to assume requester_aws_assume_role_arn


Default value: ""

requester_aws_secret_key (string) optional

Secret access key to use in requester account


Default value: null

requester_aws_token (string) optional

Session token for validating temporary credentials


Default value: null

requester_subnet_tags (map(string)) optional

Only add peer routes to requester VPC route tables of subnets matching these tags


Default value: { }

requester_vpc_id (string) optional

Requester VPC ID filter


Default value: ""

requester_vpc_tags (map(string)) optional

Requester VPC Tags filter


Default value: { }

skip_metadata_api_check (bool) optional

Don't use the credentials of EC2 instance profile


Default value: false

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

accepter_accept_status

Accepter VPC peering connection request status

accepter_connection_id

Accepter VPC peering connection ID

accepter_subnet_route_table_map

Map of accepter VPC subnet IDs to route table IDs

requester_accept_status

Requester VPC peering connection request status

requester_connection_id

Requester VPC peering connection ID

Dependencies

Requirements

  • terraform, version: >= 1.3
  • aws, version: >= 2.0

Providers

  • aws, version: >= 2.0
  • aws, version: >= 2.0

Modules

NameVersionSourceDescription
accepter0.25.0cloudposse/label/nulln/a
requester0.25.0cloudposse/label/nulln/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: