Terraform State

What is Terraform State?

Terraform stores information about your infrastructure within a state file.

Terraform uses state to determine which changes to make to your infrastructure, based on the HCL configuration it finds in your code. Changes in state will lead to the resources being modified, added or removed.

Before any changes are applied to your infrastructure, Terraform performs a refresh to sync the current state, in order to check for any resources’ that may have encountered configuration drifts.

State Commands

You can view and manipulate Terraform state using the terraform state command.

Command	Description
list	List resources in the state
mv	Move an item in the state
pull	Pull current state and output to stdout
push	Update remote state from a local state file
replace-provider	Replace provider in the state
rm	Remove instances from the state
show	Show a resource in the state

Examples

Listing all resources in the state

Example terraform state list output

data.aws_ami.latest_amazon_linux
data.aws_vpc_endpoint_service.s3
aws_instance.web_server
aws_internet_gateway.igw
aws_route.public_route
aws_route_table.private
aws_route_table.public
aws_route_table_association.private["eu-west-2a"]
aws_route_table_association.private["eu-west-2b"]
aws_route_table_association.private["eu-west-2c"]
aws_route_table_association.public["eu-west-2a"]
aws_route_table_association.public["eu-west-2b"]
aws_route_table_association.public["eu-west-2c"]
aws_security_group.web_server
aws_subnet.private["eu-west-2a"]
aws_subnet.private["eu-west-2b"]
aws_subnet.private["eu-west-2c"]
aws_subnet.public["eu-west-2a"]
aws_subnet.public["eu-west-2b"]
aws_subnet.public["eu-west-2c"]
aws_vpc.vpc
aws_vpc_endpoint.s3
aws_vpc_endpoint_route_table_association.s3_az_association

Getting details of a specific resource

Example terraform state show aws_vpc.vpc output

resource "aws_vpc" "vpc" {
    arn                                  = "arn:aws:ec2:eu-west-2:<id>:vpc/vpc-05f087bb5414aab4c"
    assign_generated_ipv6_cidr_block     = false
    cidr_block                           = "192.168.0.0/16"
    default_network_acl_id               = "acl-017e916dbee0b5d63"
    default_route_table_id               = "rtb-06b2809db725c55ef"
    default_security_group_id            = "sg-0b5a4febc36710404"
    dhcp_options_id                      = "dopt-6c222d04"
    enable_dns_hostnames                 = true
    enable_dns_support                   = true
    enable_network_address_usage_metrics = false
    id                                   = "vpc-05f087bb5414aab4c"
    instance_tenancy                     = "default"
    ipv6_netmask_length                  = 0
    main_route_table_id                  = "rtb-06b2809db725c55ef"
    owner_id                             = "<id>"
    tags                                 = {
        "App"    = "webapp"
        "Name"   = "webapp-vpc"
        "Prefix" = "webapp"
        "Region" = "eu-west-2"
    }
    tags_all                             = {
        "App"    = "webapp"
        "Name"   = "webapp-vpc"
        "Prefix" = "webapp"
        "Region" = "eu-west-2"
    }
}