Terraform Core Commands

Looking to take your Terraform workflow to the next level? Check out our comprehensive guide to Terraform Core Commands!

In this post, we’ll highlight some of the most commonly used Terraform Core Commands. So whether you’re just getting started with Terraform or you’re looking to up your game, be sure to check out this guide!

Terraform commands

–help is help

Tab completion enabled by terraform -install-autocomplete

Command	What it does?
terraform -install-autocomplete	Enables tab completion
-help	Shows the help files
apply	apply the changes
console	creates and interactive console
destroy	destroys the Terraform-managed infrastructure
fmt	used to rewrite Terraform configuration files
force-unlock	used to remove lock on the state for the current configuration
get	used to download and update modules
graph	used to generate a a graph
import	used to import existing resources
init	used to initilize a working directory
output	used to extract the value of an output variable
plan	used to create an execution plan
providers	used to print information about providers (eg VMware, AWS, HyperV etc etc etc)
push	used to upload your configuration
refresh	used to update the state of a file
show	useds to provide output from a state or plan file
state	used for advanced state management
taint	used to mark resources as tainted
validate	used to validate the syntax of terraform files
untaint	used to unmark a resourse as tainted
workspace	used to manage workspaces

Subcommands

Command	What it does
list	used to list all existing workspaces
select	used to choose different workspaces
new	used to create a new workspace
delete	used to delete and existing workspace

Terraform Syntax

The syntax of Terraform configurations is called HashiCorp Configuration Language (HCL). It is meant to strike a balance between human readable and editable as well as being machine-friendly. For machine-friendliness, Terraform can also read JSON configurations

HCL Syntax (HashiCorp Configuration Language)

Here is an example of HashiCorp Configuration Language (HCL)

# An AMI
variable "ami" {
description = "the AMI to use"
}
/* A multi
line comment. */
resource "aws_instance" "web" {
ami = "${var.ami}"
count = 2
source_dest_check = false
connection {
user = "root"
}
} 

Source: https://www.terraform.io/docs/configuration/syntax.html

JSON Syntax

Terraform also supports JSON which is a machine friendly language

{
"variable": {
"ami": {
"description": "the AMI to use"
}
},
"resource": {
"aws_instance": {
"web": {
"ami": "${var.ami}",
"count": 2,
"source_dest_check": false,
"connection": {
"user": "root"
}
}
}
}
} 

Source: https://www.terraform.io/docs/configuration/syntax.html

Variables

Type or Variable	What it does
"var" prefix	User String Variable Interpolate
"var.MAP["KEY"]	User Map Variable Value of Key
"${var.LIST}"	Value of the list as a list List elements by Index
"self.ATTRIBUTE"	Own Resource
"TYPE.NAME.ATTRIBUTE"	Other Resource
"data.TYPE.NAME.ATTRIBUTE"	Data Source
MODULE.NAME.OUTPUT"	Module outputs
"Count.FIELD"	Count
"path.TYPE"	Path
"terraform.FIELD"	Terraform Meta