»Command: console

The terraform console command provides an interactive console for evaluating expressions.

»Usage

Usage: terraform console [options]

This command provides an interactive command-line console for evaluating and experimenting with expressions. You can use it to test interpolations before using them in configurations and to interact with any values currently saved in state. If the current state is empty or has not yet been created, you can use the console to experiment with the expression syntax and built-in functions. The console holds a lock on the state, and you will not be able to use the console while performing other actions that modify state.

To close the console, enter the exit command or press Control-C or Control-D.

For configurations using the local backend only, terraform console accepts the legacy command line option -state.

»Scripting

The terraform console command can be used in non-interactive scripts by piping newline-separated commands to it. Only the output from the final command is printed unless an error occurs earlier.

For example:

$ echo 'split(",", "foo,bar,baz")' | terraform console
tolist([
  "foo",
  "bar",
  "baz",
])

$ echo 'split(",", "foo,bar,baz")' | terraform console
tolist([
  "foo",
  "bar",
  "baz",
])

»Remote State

If remote state is used by the current backend, Terraform will read the state for the current workspace from the backend before evaluating any expressions.

»Examples

The terraform console command will read the Terraform configuration in the current working directory and the Terraform state file from the configured backend so that interpolations can be tested against both the values in the configuration and the state file.

With the following main.tf:

variable "apps" {
  type = map(any)
  default = {
    "foo" = {
      "region" = "us-east-1",
    },
    "bar" = {
      "region" = "eu-west-1",
    },
    "baz" = {
      "region" = "ap-south-1",
    },
  }
}

resource "random_pet" "example" {
  for_each = var.apps
}

variable "apps" {
  type = map(any)
  default = {
    "foo" = {
      "region" = "us-east-1",
    },
    "bar" = {
      "region" = "eu-west-1",
    },
    "baz" = {
      "region" = "ap-south-1",
    },
  }
}

resource "random_pet" "example" {
  for_each = var.apps
}

Executing terraform console will drop you into an interactive shell where you can test interpolations to:

Print a value from a map:

> var.apps.foo
{
  "region" = "us-east-1"
}

> var.apps.foo
{
  "region" = "us-east-1"
}

Filter a map based on a specific value:

> { for key, value in var.apps : key => value if value.region == "us-east-1" }
{
  "foo" = {
    "region" = "us-east-1"
  }
}

> { for key, value in var.apps : key => value if value.region == "us-east-1" }
{
  "foo" = {
    "region" = "us-east-1"
  }
}

Check if certain values may not be known until apply:

> random_pet.example
(known after apply)

> random_pet.example
(known after apply)

Test various functions:

> cidrnetmask("172.16.0.0/12")
"255.240.0.0"

> cidrnetmask("172.16.0.0/12")
"255.240.0.0"