Skip to main content

Component: vpc

This component is responsible for provisioning a VPC and corresponding Subnets. Additionally, VPC Flow Logs can optionally be enabled for auditing purposes. See the existing VPC configuration documentation for the provisioned subnets.


Stack Level: Regional

Here's an example snippet for how to use this component.

# catalog/vpc/defaults or catalog/vpc
type: abstract
component: vpc
workspace_enabled: true
enabled: true
name: vpc
- "a"
- "b"
- "c"
nat_gateway_enabled: true
nat_instance_enabled: false
max_subnet_count: 3
vpc_flow_logs_enabled: true
vpc_flow_logs_bucket_environment_name: <environment>
vpc_flow_logs_bucket_stage_name: audit
vpc_flow_logs_traffic_type: "ALL"
subnet_type_tag_key: ""
assign_generated_ipv6_cidr_block: true
- catalog/vpc

component: vpc
- vpc/defaults
ipv4_primary_cidr_block: ""


terraform>= 1.0.0
aws>= 4.9.0


aws>= 4.9.0




aws_caller_identity.currentdata source
aws_eip.eipdata source


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.
assign_generated_ipv6_cidr_blockWhen true, assign AWS generated IPv6 CIDR block to the VPC. Conflicts with ipv6_ipam_pool_id.boolfalseno
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.
availability_zone_idsList of Availability Zones IDs where subnets will be created. Overrides availability_zones.
Can be the full name, e.g. use1-az1, or just the part after the AZ ID region code, e.g. -az1,
to allow reusable values across regions. Consider contention for resources and spot pricing in each AZ when selecting.
Useful in some regions when using only some AZs and you want to use the same ones across multiple accounts.
availability_zonesList of Availability Zones (AZs) where subnets will be created. Ignored when availability_zone_ids is set.
Can be the full name, e.g. us-east-1a, or just the part after the region, e.g. a to allow reusable values across regions.
The order of zones in the list must be stable or else Terraform will continually make changes.
If no AZs are specified, then max_subnet_count AZs will be selected in alphabetical order.
If max_subnet_count > 0 and length(var.availability_zones) > max_subnet_count, the list
will be truncated. We recommend setting availability_zones and max_subnet_count explicitly as constant
(not computed) values for predictability, consistency, and stability.
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.
"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": [
"name": null,
"namespace": null,
"regex_replace_chars": null,
"stage": null,
"tags": {},
"tenant": null
delimiterDelimiter to be used between ID elements.
Defaults to - (hyphen). Set to "" to use no delimiter at all.
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).
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
gateway_vpc_endpointsA list of Gateway VPC Endpoints to provision into the VPC. Only valid values are "dynamodb" and "s3".set(string)[]no
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.
interface_vpc_endpointsA list of Interface VPC Endpoints to provision into the VPC.set(string)[]no
ipv4_additional_cidr_block_associationsIPv4 CIDR blocks to assign to the VPC.
ipv4_cidr_block can be set explicitly, or set to null with the CIDR block derived from ipv4_ipam_pool_id using ipv4_netmask_length.
Map keys must be known at plan time, and are only used to track changes.
ipv4_cidr_block = string
ipv4_ipam_pool_id = string
ipv4_netmask_length = number
ipv4_cidr_block_association_timeoutsTimeouts (in go duration format) for creating and destroying IPv4 CIDR block associations
create = string
delete = string
ipv4_cidrsLists of CIDRs to assign to subnets. Order of CIDRs in the lists must not change over time.
Lists may contain more CIDRs than needed.
private = list(string)
public = list(string)
ipv4_primary_cidr_blockThe primary IPv4 CIDR block for the VPC.
Either ipv4_primary_cidr_block or ipv4_primary_cidr_block_association must be set, but not both.
ipv4_primary_cidr_block_associationConfiguration of the VPC's primary IPv4 CIDR block via IPAM. Conflicts with ipv4_primary_cidr_block.
One of ipv4_primary_cidr_block or ipv4_primary_cidr_block_association must be set.
Additional CIDR blocks can be set via ipv4_additional_cidr_block_associations.
ipv4_ipam_pool_id = string
ipv4_netmask_length = number
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.
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.
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.
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.
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.
map_public_ip_on_launchInstances launched into a public subnet should be assigned a public IP addressbooltrueno
max_subnet_countSets the maximum amount of subnets to deploy. 0 will deploy a subnet for every provided availability zone (in region_availability_zones variable) within the regionnumber0no
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.
namespaceID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally uniquestringnullno
nat_eip_aws_shield_protection_enabledEnable or disable AWS Shield Advanced protection for NAT EIPs. If set to 'true', a subscription to AWS Shield Advanced must exist in this account.boolfalseno
nat_gateway_enabledFlag to enable/disable NAT gatewaysbooltrueno
nat_instance_ami_idA list optionally containing the ID of the AMI to use for the NAT instance.
If the list is empty (the default), the latest official AWS NAT instance AMI
will be used. NOTE: The Official NAT instance AMI is being phased out and
does not support NAT64. Use of a NAT gateway is recommended instead.
nat_instance_enabledFlag to enable/disable NAT instancesboolfalseno
nat_instance_typeNAT Instance typestring"t3.micro"no
public_subnets_enabledIf false, do not create public subnets.
Since NAT gateways and instances must be created in public subnets, these will also not be created when false.
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.
regionAWS Regionstringn/ayes
stageID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'stringnullno
subnet_type_tag_keyKey for subnet type tag to provide information about the type of subnets, e.g. cpco/subnet/type=private or cpcp/subnet/type=publicstringn/ayes
subnets_per_az_countThe number of subnet of each type (public or private) to provision per Availability Zone.number1no
subnets_per_az_namesThe subnet names of each type (public or private) to provision per Availability Zone.
This variable is optional.
If a list of names is provided, the list items will be used as keys in the outputs named_private_subnets_map, named_public_subnets_map,
named_private_route_table_ids_map and named_public_route_table_ids_map
tagsAdditional tags (e.g. {'BusinessUnit': 'XYZ'}).
Neither the tag keys nor the tag values will be modified by this module.
tenantID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is forstringnullno
vpc_flow_logs_bucket_environment_nameThe name of the environment where the VPC Flow Logs bucket is provisionedstring""no
vpc_flow_logs_bucket_stage_nameThe stage (account) name where the VPC Flow Logs bucket is provisionedstring""no
vpc_flow_logs_bucket_tenant_nameThe name of the tenant where the VPC Flow Logs bucket is provisioned.

If the tenant label is not used, leave this as null.
vpc_flow_logs_enabledEnable or disable the VPC Flow Logsbooltrueno
vpc_flow_logs_log_destination_typeThe type of the logging destination. Valid values: cloud-watch-logs, s3string"s3"no
vpc_flow_logs_traffic_typeThe type of traffic to capture. Valid values: ACCEPT, REJECT, ALLstring"ALL"no


availability_zonesList of Availability Zones where subnets were created
az_private_subnets_mapMap of AZ names to list of private subnet IDs in the AZs
az_public_subnets_mapMap of AZ names to list of public subnet IDs in the AZs
interface_vpc_endpointsList of Interface VPC Endpoints in this VPC.
max_subnet_countMaximum allowed number of subnets before all subnet CIDRs need to be recomputed
nat_eip_protectionsList of AWS Shield Advanced Protections for NAT Elastic IPs.
nat_gateway_idsNAT Gateway IDs
nat_gateway_public_ipsNAT Gateway public IPs
nat_instance_idsNAT Instance IDs
private_route_table_idsPrivate subnet route table IDs
private_subnet_cidrsPrivate subnet CIDRs
private_subnet_idsPrivate subnet IDs
public_route_table_idsPublic subnet route table IDs
public_subnet_cidrsPublic subnet CIDRs
public_subnet_idsPublic subnet IDs
route_tablesRoute tables info map
subnetsSubnets info map
vpcVPC info map
vpc_cidrVPC CIDR
vpc_default_network_acl_idThe ID of the network ACL created by default on VPC creation
vpc_default_security_group_idThe ID of the security group created by default on VPC creation
vpc_idVPC ID