IBM Secure Landing Zone VPC module

This module creates the following IBM Cloud® Virtual Private Cloud (VPC) network components:

• VPC: Creates a VPC in a resource group and supports classic access. The VPC and components are specified in the main.tf file.
• Public gateways: Optionally create public gateways in the VPC in each of the three zones of the VPC's region.
• Subnets: Create one to three zones in the subnet.tf file.
• Network ACLs: Create network ACLs with multiple rules. By default, VPC network ACLs can have no more than 25 rules.
• VPN gateways: Create VPN gateways on your subnets by using the vpn_gateways variable. For more information about VPN gateways on VPC, see About site-to-site VPN gateways in the IBM Cloud docs.
• VPN gateway connections: Add connections to a VPN gateway.
• Hub and spoke DNS-sharing model: Optionally create a hub or spoke VPC, with associated custom resolver and DNS resolution binding, as well as a service-to-service authorization policy which supports the hub and spoke VPCs to be in separate accounts. See About DNS sharing for VPE gateways in the IBM Cloud docs for details.

Overview

• terraform-ibm-landing-zone-vpc
• Submodules
  • management-vpc
  • workload-vpc
• Examples
  • Basic Example
  • Default Example
  • Existing VPC and subnets Example
  • Hub and Spoke VPC Example
  • Hub and Spoke VPC with manual DNS resolver Example
  • Landing Zone example
  • No Prefix Example
• Contributing

terraform-ibm-landing-zone-vpc

Presets

In addition to this root module, this repository provides two submodules that call the root module with presets and defaults that are aligned with the general Framework for Financial Services management and workload VPC topologies. See the modules for details.

Usage

module vpc {
  source              = "terraform-ibm-modules/landing-zone-vpc/ibm"
  version             = "X.X.X" # Replace "X.X.X" with a release version to lock into a specific release
  resource_group_id   = var.resource_group_id
  region              = var.region
  prefix              = var.prefix
  tags                = var.tags
  vpc_name            = var.vpc_name
  classic_access      = var.classic_access
  network_acls        = var.network_acls
  use_public_gateways = var.use_public_gateways
  subnets             = var.subnets
  vpn_gateways        = var.vpn_gateways
}

Resource naming

The module automatically generates names for the all provisioned VPC resources using the var.prefix input variable. You can selectively override this behavior by giving explicit names through the following input variables: name (for VPC name), dns_binding_name, dns_instance_name, dns_custom_resolver_name, routing_table_name, public_gateway_name, and vpc_flow_logs_name.

Subnets

You can create a maximum of three zones in the subnet.tf file. The zones are defined as lists in the file, and then are converted to objects before the resources are provisioned. The conversion ensures that the addition or deletion of subnets affects only the added or deleted subnets, as shown in the following example.

module.subnets.ibm_is_subnet.subnet["gcat-multizone-subnet-a"]
module.subnets.ibm_is_subnet.subnet["gcat-multizone-subnet-b"]
module.subnets.ibm_is_subnet.subnet["gcat-multizone-subnet-c"]
module.subnets.ibm_is_vpc_address_prefix.subnet_prefix["gcat-multizone-subnet-a"]
module.subnets.ibm_is_vpc_address_prefix.subnet_prefix["gcat-multizone-subnet-b"]
module.subnets.ibm_is_vpc_address_prefix.subnet_prefix["gcat-multizone-subnet-c"]

Required IAM access policies

You need the following permissions to run this module.

• IAM services
  • VPC Infrastructure services
    • Editor platform access
  • No service access
    • Resource Group <your resource group>
    • Viewer resource group access

To attach access management tags to resources in this module, you need the following permissions.

• IAM Services
  • Tagging service
    • Administrator platform access

Requirements

Name	Version
terraform	>= 1.3.0, <1.7.0
ibm	>= 1.59.0, < 2.0.0
time	>= 0.9.1, < 1.0.0

Modules

Name	Source	Version
dynamic_values	./dynamic_values	n/a
unit_tests	./dynamic_values	n/a

Resources

Name	Type
ibm_dns_custom_resolver.custom_resolver_hub	resource
ibm_iam_authorization_policy.policy	resource
ibm_iam_authorization_policy.vpc_dns_resolution_auth_policy	resource
ibm_is_flow_log.flow_logs	resource
ibm_is_network_acl.network_acl	resource
ibm_is_public_gateway.gateway	resource
ibm_is_security_group_rule.default_vpc_rule	resource
ibm_is_subnet.subnet	resource
ibm_is_subnet_public_gateway_attachment.exist_subnet_gw	resource
ibm_is_vpc.vpc	resource
ibm_is_vpc_address_prefix.address_prefixes	resource
ibm_is_vpc_address_prefix.subnet_prefix	resource
ibm_is_vpc_dns_resolution_binding.vpc_dns_resolution_binding_crn	resource
ibm_is_vpc_dns_resolution_binding.vpc_dns_resolution_binding_id	resource
ibm_is_vpc_routing_table.route_table	resource
ibm_is_vpc_routing_table_route.routing_table_routes	resource
ibm_resource_instance.dns_instance_hub	resource
time_sleep.wait_for_authorization_policy	resource
time_sleep.wait_for_vpc_creation_data	resource
ibm_iam_account_settings.iam_account_settings	data source
ibm_is_subnet.subnet	data source
ibm_is_vpc.vpc	data source
ibm_is_vpc_address_prefixes.get_address_prefixes	data source

Inputs

Name	Description	Type	Default	Required
access_tags	A list of access tags to apply to the VPC resources created by the module. For more information, see https://cloud.ibm.com/docs/account?topic=account-access-tags-tutorial.	list(string)	[]	no
address_prefixes	OPTIONAL - IP range that will be defined for the VPC for a certain location. Use only with manual address prefixes	object({ zone-1 = optional(list(string)) zone-2 = optional(list(string)) zone-3 = optional(list(string)) })	{ "zone-1": null, "zone-2": null, "zone-3": null }	no
classic_access	OPTIONAL - Classic Access to the VPC	bool	false	no
clean_default_sg_acl	Remove all rules from the default VPC security group and VPC ACL (less permissive)	bool	false	no
create_authorization_policy_vpc_to_cos	Create authorisation policy for VPC to access COS. Set as false if authorization policy exists already	bool	false	no
create_subnets	Indicates whether user wants to use existing subnets or create new. Set it to true to create new subnets.	bool	true	no
create_vpc	Indicates whether user wants to use an existing vpc or create a new one. Set it to true to create a new vpc	bool	true	no
default_network_acl_name	OPTIONAL - Name of the Default ACL. If null, a name will be automatically generated	string	null	no
default_routing_table_name	OPTIONAL - Name of the Default Routing Table. If null, a name will be automatically generated	string	null	no
default_security_group_name	OPTIONAL - Name of the Default Security Group. If null, a name will be automatically generated	string	null	no
dns_binding_name	The name to give the provisioned VPC DNS resolution binding. If not set, the module generates a name based on the prefix and name variables.	string	null	no
dns_custom_resolver_name	The name to give the provisioned DNS custom resolver instance. If not set, the module generates a name based on the prefix and name variables.	string	null	no
dns_instance_name	The name to give the provisioned DNS instance. If not set, the module generates a name based on the prefix and name variables.	string	null	no
dns_location	The target location or environment for the DNS instance created to host the custom resolver in a hub-spoke DNS resolution topology. Only used if enable_hub is true and skip_custom_resolver_hub_creation is false (defaults).	string	"global"	no
dns_plan	The plan for the DNS resource instance created to host the custom resolver in a hub-spoke DNS resolution topology. Only used if enable_hub is true and skip_custom_resolver_hub_creation is false (defaults).	string	"standard-dns"	no
enable_hub	Indicates whether this VPC is enabled as a DNS name resolution hub.	bool	false	no
enable_hub_vpc_crn	Indicates whether Hub VPC CRN is passed.	bool	false	no
enable_hub_vpc_id	Indicates whether Hub VPC ID is passed.	bool	false	no
enable_vpc_flow_logs	Flag to enable vpc flow logs. If true, flow log collector will be created	bool	false	no
existing_cos_instance_guid	GUID of the COS instance to create Flow log collector	string	null	no
existing_dns_instance_id	Id of an existing dns instance in which the custom resolver is created. Only relevant if enable_hub is set to true.	string	null	no
existing_storage_bucket_name	Name of the COS bucket to collect VPC flow logs	string	null	no
existing_subnets	The detail of the existing subnets and required mappings to other resources. Required if 'create_subnets' is false.	list(object({ id = string public_gateway = optional(bool, false) }))	[]	no
existing_vpc_id	The ID of the existing vpc. Required if 'create_vpc' is false.	string	null	no
hub_account_id	ID of the hub account for DNS resolution, required if 'skip_spoke_auth_policy' is false.	string	null	no
hub_vpc_crn	Indicates the crn of the hub VPC for DNS resolution. See https://cloud.ibm.com/docs/vpc?topic=vpc-hub-spoke-model. Mutually exclusive with hub_vpc_id.	string	null	no
hub_vpc_id	Indicates the id of the hub VPC for DNS resolution. See https://cloud.ibm.com/docs/vpc?topic=vpc-hub-spoke-model. Mutually exclusive with hub_vpc_crn.	string	null	no
is_flow_log_collector_active	Indicates whether the collector is active. If false, this collector is created in inactive mode.	bool	true	no
manual_servers	The DNS server addresses to use for the VPC, replacing any existing servers. All the entries must either have a unique zone_affinity, or not have a zone_affinity.	list(object({ address = string zone_affinity = optional(string) }))	[]	no
name	Used for the naming of the VPC (if create_vpc is set to true), as well as in the naming for any resources created inside the VPC (unless using one of the optional variables for explicit control over naming).	string	n/a	yes
network_acls	The list of ACLs to create. Provide at least one rule for each ACL.	list( object({ name = string add_ibm_cloud_internal_rules = optional(bool) add_vpc_connectivity_rules = optional(bool) prepend_ibm_rules = optional(bool) rules = list( object({ name = string action = string destination = string direction = string source = string tcp = optional( object({ port_max = optional(number) port_min = optional(number) source_port_max = optional(number) source_port_min = optional(number) }) ) udp = optional( object({ port_max = optional(number) port_min = optional(number) source_port_max = optional(number) source_port_min = optional(number) }) ) icmp = optional( object({ type = optional(number) code = optional(number) }) ) }) ) }) )	[ { "add_ibm_cloud_internal_rules": true, "add_vpc_connectivity_rules": true, "name": "vpc-acl", "prepend_ibm_rules": true, "rules": [] } ]	no
network_cidrs	List of Network CIDRs for the VPC. This is used to manage network ACL rules for cluster provisioning.	list(string)	[ "10.0.0.0/8" ]	no
prefix	The value that you would like to prefix to the name of the resources provisioned by this module. Explicitly set to null if you do not wish to use a prefix. This value is ignored if using one of the optional variables for explicit control over naming.	string	null	no
public_gateway_name	The name to give the provisioned VPC public gateways. If not set, the module generates a name based on the prefix and name variables.	string	null	no
region	The region to which to deploy the VPC	string	n/a	yes
resolver_type	Resolver type. Can be system or manual. For delegated resolver type, see the update_delegated_resolver variable instead.	string	null	no
resource_group_id	The resource group ID where the VPC to be created	string	n/a	yes
routes	OPTIONAL - Allows you to specify the next hop for packets based on their destination address	list( object({ name = string route_direct_link_ingress = optional(bool) route_transit_gateway_ingress = optional(bool) route_vpc_zone_ingress = optional(bool) routes = optional( list( object({ action = optional(string) zone = number destination = string next_hop = string }) )) }) )	[]	no
routing_table_name	The name to give the provisioned routing tables. If not set, the module generates a name based on the prefix and name variables.	string	null	no
security_group_rules	A list of security group rules to be added to the default vpc security group (default empty)	list( object({ name = string direction = string remote = string tcp = optional( object({ port_max = optional(number) port_min = optional(number) }) ) udp = optional( object({ port_max = optional(number) port_min = optional(number) }) ) icmp = optional( object({ type = optional(number) code = optional(number) }) ) }) )	[]	no
skip_custom_resolver_hub_creation	Indicates whether to skip the configuration of a custom resolver in the hub VPC. Only relevant if enable_hub is set to true.	bool	false	no
skip_spoke_auth_policy	Set to true to skip the creation of an authorization policy between the DNS resolution spoke and hub, only enable this if a policy already exists between these two VPCs. See https://cloud.ibm.com/docs/vpc?topic=vpc-vpe-dns-sharing-s2s-auth&interface=ui for more details.	bool	false	no
subnets	List of subnets for the vpc. For each item in each array, a subnet will be created. Items can be either CIDR blocks or total ipv4 addressess. Public gateways will be enabled only in zones where a gateway has been created	object({ zone-1 = list(object({ name = string cidr = string public_gateway = optional(bool) acl_name = string no_addr_prefix = optional(bool, false) # do not automatically add address prefix for subnet, overrides other conditions if set to true })) zone-2 = optional(list(object({ name = string cidr = string public_gateway = optional(bool) acl_name = string no_addr_prefix = optional(bool, false) # do not automatically add address prefix for subnet, overrides other conditions if set to true }))) zone-3 = optional(list(object({ name = string cidr = string public_gateway = optional(bool) acl_name = string no_addr_prefix = optional(bool, false) # do not automatically add address prefix for subnet, overrides other conditions if set to true }))) })	{ "zone-1": [ { "acl_name": "vpc-acl", "cidr": "10.10.10.0/24", "name": "subnet-a", "no_addr_prefix": false, "public_gateway": true } ], "zone-2": [ { "acl_name": "vpc-acl", "cidr": "10.20.10.0/24", "name": "subnet-b", "no_addr_prefix": false, "public_gateway": true } ], "zone-3": [ { "acl_name": "vpc-acl", "cidr": "10.30.10.0/24", "name": "subnet-c", "no_addr_prefix": false, "public_gateway": false } ] }	no
tags	List of Tags for the resource created	list(string)	null	no
update_delegated_resolver	If set to true, and if the vpc is configured to be a spoke for DNS resolution (enable_hub_vpc_crn or enable_hub_vpc_id set), then the spoke VPC resolver will be updated to a delegated resolver.	bool	false	no
use_existing_dns_instance	Whether to use an existing dns instance. If true, existing_dns_instance_id must be set.	bool	false	no
use_public_gateways	Create a public gateway in any of the three zones with true.	object({ zone-1 = optional(bool) zone-2 = optional(bool) zone-3 = optional(bool) })	{ "zone-1": true, "zone-2": false, "zone-3": false }	no
vpc_flow_logs_name	The name to give the provisioned VPC flow logs. If not set, the module generates a name based on the prefix and name variables.	string	null	no

Outputs

Name	Description
cidr_blocks	List of CIDR blocks present in VPC stack
custom_resolver_hub	The custom resolver created for the hub vpc. Only set if enable_hub is set and skip_custom_resolver_hub_creation is false.
dns_endpoint_gateways_by_crn	The list of VPEs that are made available for DNS resolution in the created VPC. Only set if enable_hub is false and enable_hub_vpc_id are true.
dns_endpoint_gateways_by_id	The list of VPEs that are made available for DNS resolution in the created VPC. Only set if enable_hub is false and enable_hub_vpc_id are true.
network_acls	List of shortnames and IDs of network ACLs
public_gateways	Map of public gateways by zone
subnet_detail_list	A list of subnets containing names, CIDR blocks, and zones.
subnet_detail_map	A map of subnets containing IDs, CIDR blocks, and zones
subnet_ids	The IDs of the subnets
subnet_zone_list	A list containing subnet IDs and subnet zones
vpc_crn	CRN of VPC created
vpc_data	Data of the VPC used in this module, created or existing.
vpc_flow_logs	Details of VPC flow logs collector
vpc_id	ID of VPC created
vpc_name	Name of VPC created

Contributing

You can report issues and request features for this module in GitHub issues in the module repo. See Report an issue or request a feature.

To set up your local development environment, see Local development setup in the project documentation.