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Component: tgw/hub

This component is responsible for provisioning an AWS Transit Gateway hub that acts as a centralized gateway for connecting VPCs from other spoke accounts.

Usage

Stack Level: Regional

Here's an example snippet for how to configure and use this component:

components:
terraform:
tgw/hub/defaults:
metadata:
type: abstract
component: tgw/hub
vars:
enabled: true
name: tgw-hub
expose_eks_sg: false
tags:
Team: sre
Service: tgw-hub

tgw/hub:
metadata:
inherits:
- tgw/hub/defaults
component: tgw/hub
vars:
connections:
- account:
tenant: core
stage: network
vpc_component_names:
- vpc-dev
- account:
tenant: core
stage: artifacts
- account:
tenant: core
stage: auto
eks_component_names:
- eks/cluster
- account:
tenant: plat
stage: dev
vpc_component_names:
- vpc
- vpc/data/1
eks_component_names:
- eks/cluster
- account:
tenant: plat
stage: staging
vpc_component_names:
- vpc
- vpc/data/1
eks_component_names:
- eks/cluster
- account:
tenant: plat
stage: prod
vpc_component_names:
- vpc
- vpc/data/1
eks_component_names:
- eks/cluster

To provision the Transit Gateway and all related resources, run the following commands:

atmos terraform plan tgw/hub -s <tenant>-<environment>-network
atmos terraform apply tgw/hub -s <tenant>-<environment>-network

Requirements

NameVersion
terraform>= 1.0.0
aws>= 4.1

Providers

No providers.

Modules

NameSourceVersion
account_mapcloudposse/stack-config/yaml//modules/remote-state1.5.0
ekscloudposse/stack-config/yaml//modules/remote-state1.5.0
iam_roles../../account-map/modules/iam-rolesn/a
tgw_hubcloudposse/transit-gateway/aws0.11.0
thiscloudposse/label/null0.25.0
vpccloudposse/stack-config/yaml//modules/remote-state1.5.0

Resources

No resources.

Inputs

NameDescriptionTypeDefaultRequired
account_map_environment_nameThe name of the environment where account_map is provisionedstring"gbl"no
account_map_stage_nameThe name of the stage where account_map is provisionedstring"root"no
account_map_tenant_nameThe name of the tenant where account_map is provisioned.

If the tenant label is not used, leave this as null.
stringnullno
additional_tag_mapAdditional 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
allow_external_principalsSet true to allow the TGW to be RAM shared with external principals specified in ram_principalsboolfalseno
attributesID 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
connectionsA list of objects to define each TGW connections.

By default, each connection will look for only the default vpc component.
list(object({
account = object({
stage = string
environment = optional(string, "")
tenant = optional(string, "")
})
vpc_component_names = optional(list(string), ["vpc"])
eks_component_names = optional(list(string), [])
}))
[]no
contextSingle 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
delimiterDelimiter to be used between ID elements.
Defaults to - (hyphen). Set to "" to use no delimiter at all.
stringnullno
descriptor_formatsDescribe 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
enabledSet to false to prevent the module from creating any resourcesboolnullno
environmentID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'stringnullno
expose_eks_sgSet true to allow EKS clusters to accept traffic from source accountsbooltrueno
id_length_limitLimit 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.
numbernullno
label_key_caseControls 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.
stringnullno
label_orderThe 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)nullno
label_value_caseControls 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.
stringnullno
labels_as_tagsSet 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
nameID 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.
stringnullno
namespaceID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally uniquestringnullno
ram_principalsA list of AWS account IDs to share the TGW with outside the organizationlist(string)[]no
regex_replace_charsTerraform 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.
stringnullno
regionAWS Regionstringn/ayes
stageID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'stringnullno
tagsAdditional tags (e.g. {'BusinessUnit': 'XYZ'}).
Neither the tag keys nor the tag values will be modified by this module.
map(string){}no
tenantID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is forstringnullno

Outputs

NameDescription
eksAccounts with EKS and EKSs information
tgw_configTransit Gateway config
transit_gateway_arnTransit Gateway ARN
transit_gateway_idTransit Gateway ID
transit_gateway_route_table_idTransit Gateway route table ID
vpcsAccounts with VPC and VPCs information

References