v4.x to v5.x Changes

Variables

create_vpc -> create
cidr -> cidr_block to match Terraform AWS provider
enable_ipv6 -> assign_generated_ipv6_cidr_block to match Terraform AWS provider
aws_default_route_table.default -> aws_default_route_table.this to align with convention
enable_dhcp_options -> create_dhcp_options to align with conventions

Added destination_prefix_list_id attribute for default route table route(s)
Added var.default_route_table_name variable to allow setting route table name and align with rest of default resources
Added support for aws_default_vpc_dhcp_options

secondary_cidr_blocks was changed from a count/list in the aws_vpc_ipv4_cidr_block_association resource to a for_each/toset(list)
manage_default_security_group default value changed from false to true
Tags for custom names have been updated to coalesce with "default-${var.name}" if a custom name is not provided instead of defaulting to ""
Default route table timeouts that were hardcoded at 5m have been replaced with a variable var.default_route_table_timeouts that default to null

Default network ACLs ingress and egress rules are now cleared when adopted to conform with AWS recommended practices. Users will need to specify ingress/egress rules if they decide to use the default ACL

  terraform state mv 'module.vpc.aws_default_route_table.default[0]' 'module.vpc.aws_default_route_table.this[0]'