Override Tags Reference

Tags with the simfra: prefix let you create AWS resources with exact IDs. Override tags are extracted during resource creation, applied to the resource ID, and then stripped - they never appear in API responses such as DescribeTags or ListTags.

For usage examples and Terraform patterns, see Resource ID Overrides.

Tag Reference

Tag	Resource	Applied During	Format	Example Value
`simfra:KeyId`	KMS Key	`CreateKey`	UUID	`12345678-1234-1234-1234-123456789012`
`simfra:VpcId`	VPC	`CreateVpc`	`vpc-` + 8-32 hex chars	`vpc-0abc123def456789ab`
`simfra:DefaultSecurityGroupId`	Default Security Group	`CreateVpc` (auto-created with VPC)	`sg-` + hex	`sg-0abc123def456789ab`
`simfra:MainRouteTableId`	Main Route Table	`CreateVpc` (auto-created with VPC)	`rtb-` + hex	`rtb-0abc123def456789ab`
`simfra:DefaultNetworkAclId`	Default Network ACL	`CreateVpc` (auto-created with VPC)	`acl-` + hex	`acl-0abc123def456789ab`
`simfra:SubnetId`	Subnet	`CreateSubnet`	`subnet-` + hex	`subnet-0abc123def456789ab`
`simfra:InstanceId`	EC2 Instance	`RunInstances`	`i-` + hex (comma-separated for multiple)	`i-0abc123def456789ab`
`simfra:GroupId`	Security Group	`CreateSecurityGroup`	`sg-` + hex	`sg-0abc123def456789ab`
`simfra:InternetGatewayId`	Internet Gateway	`CreateInternetGateway`	`igw-` + hex	`igw-0abc123def456789ab`

Rules

Validation - Override values are validated for correct format. A simfra:VpcId value of bad-id is rejected with an error.
Uniqueness - Duplicate IDs are rejected. If a resource with the given ID already exists, the create operation fails.
Stripping - Override tags are consumed and discarded. Only non-simfra: tags are stored on the resource.
Optional - When no simfra: tags are present, resources get auto-generated IDs as usual.
VPC compound overrides - CreateVpc accepts multiple override tags in the same tag set. The VPC ID, default security group, main route table, and default NACL can all be pinned in a single call.
Multi-instance - simfra:InstanceId accepts comma-separated values when launching multiple instances with RunInstances (one ID per instance, in order).