}
Example: Create a file on a local host where Terraform is installed.
resource is the reserved word and is the block name. Each resource is uniquely defined by the combination of the resource type and name. In our example:
- "local_file" is a predefined string which denotes the resource type:
- local - resource provider (by convention, resource type names start with their provider's preferred local name)
- file - resource type
- "foo" is the logical resource name; this is a local name that can be used from the same Terraform module
Inside the curly braces (resource block) are arguments for resource. They are specific for the given resource type. In this example, we are using local_file | Resources | hashicorp/local | Terraform Registry.
- local
- aws
- azure
- gcp
- ...
Each resource type has its own set of arguments.
Example: Create Amazon Machine Image (AMI)
aws-ec2.tf:
Example: S3
aws-s3.tf:
- write .tf file
- (optional) run terraform fmt command which scans .tf files in current working directory and formats them in the canonical format. This improves the readability of configuration files.
- run terraform init command. It:
- checks the .tf config file
- initializes the working directory containing .tf file
- from .tf file it finds out what type of resource(s) we want to create
- it initializes specified providers - it downloads plugin(s) required in order to work on these resources
- is a safe command. It can be many times without affecting the infrastructure that is being deployed.
- (optional) run terraform validate to validate configuration file syntax
- run terraform plan command in order to review the execution plan
- run terraform apply command to apply changes
- run terraform show command in order to see the changes made; it prints the current state of the infrastructure; it prints all resources and values of their attributes. Use -json flag to print it in JSON format.
- run terraform destroy to destroy created resources
terraform init
. .. create_local_file_demo.tf
resource "local_file" "foo" {
filename = "${path.cwd}/temp/foo.txt"
content = "This is a text content of the foo file!"
}
Initializing the backend...
Initializing provider plugins...
- Finding latest version of hashicorp/local...
- Installing hashicorp/local v2.2.2...
- Installed hashicorp/local v2.2.2 (signed by HashiCorp)
Terraform has created a lock file .terraform.lock.hcl to record the provider
selections it made above. Include this file in your version control repository
so that Terraform can guarantee to make the same selections by default when
you run "terraform init" in the future.
Terraform has been successfully initialized!
You may now begin working with Terraform. Try running "terraform plan" to see
any changes that are required for your infrastructure. All Terraform commands
should now work.
If you ever set or change modules or backend configuration for Terraform,
rerun this command to reinitialize your working directory. If you forget, other
commands will detect it and remind you to do so if necessary.
. .. create_local_file_demo.tf .terraform .terraform.lock.hcl
-rwxr-xr-x 1 bojan bojan 13864960 Mar 28 13:27 providers/registry.terraform.io/hashicorp/local/2.2.2/linux_amd64/terraform-provider-local_v2.2.2_x5
# This file is maintained automatically by "terraform init".
# Manual edits may be lost in future updates.
provider "registry.terraform.io/hashicorp/local" {
version = "2.2.2"
hashes = [
"h1:5UYW2wJ320IggrzLt8tLD6MowePqycWtH1b2RInHZkE=",
"zh:027e4873c69da214e2fed131666d5de92089732a11d096b68257da54d30b6f9d",
"zh:0ba2216e16cfb72538d76a4c4945b4567a76f7edbfef926b1c5a08d7bba2a043",
"zh:1fee8f6aae1833c27caa96e156cf99a681b6f085e476d7e1b77d285e21d182c1",
"zh:2e8a3e72e877003df1c390a231e0d8e827eba9f788606e643f8e061218750360",
"zh:719008f9e262aa1523a6f9132adbe9eee93c648c2981f8359ce41a40e6425433",
"zh:78d5eefdd9e494defcb3c68d282b8f96630502cac21d1ea161f53cfe9bb483b3",
"zh:9a70fdbe6ef955c4919a4519caca116f34c19c7ddedd77990fbe4f80fe66dc84",
"zh:abc412423d670cbb6264827fa80e1ffdc4a74aff3f19ba6a239dd87b85b15bec",
"zh:ae953a62c94d2a2a0822e5717fafc54e454af57bd6ed02cd301b9786765c1dd3",
"zh:be0910bdf46698560f9e86f51a4ff795c62c02f8dc82b2b1dab77a0b3a93f61e",
"zh:e58f9083b7971919b95f553227adaa7abe864fce976f0166cf4d65fc17257ff2",
"zh:ff4f77cbdbb22cc98182821c7ef84dce16298ab0e997d5c7fae97247f7a4bcb0",
]
}
terraform validate
terraform plan
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
+ create
Terraform will perform the following actions:
# local_file.foo will be created
+ resource "local_file" "foo" {
+ content = "This is a text content of the foo file!"
+ directory_permission = "0777"
+ file_permission = "0777"
+ filename = "/home/bojan/dev/github/demo-terraform/local_resources_demo/temp/foo.txt"
+ id = (known after apply)
}
Plan: 1 to add, 0 to change, 0 to destroy.
Note: You didn't use the -out option to save this plan, so Terraform can't guarantee to take exactly these actions if you run "terraform apply" now.
terraform apply
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
+ create
Terraform will perform the following actions:
# local_file.foo will be created
+ resource "local_file" "foo" {
+ content = "This is a text content of the foo file!"
+ directory_permission = "0777"
+ file_permission = "0777"
+ filename = "/home/bojan/dev/github/demo-terraform/local_resources_demo/temp/foo.txt"
+ id = (known after apply)
}
Plan: 1 to add, 0 to change, 0 to destroy.
Do you want to perform these actions?
Terraform will perform the actions described above.
Only 'yes' will be accepted to approve.
Enter a value: yes
local_file.foo: Creating...
local_file.foo: Creation complete after 0s [id=db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e]
Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
This is a text content of the foo file!
{
"version": 4,
"terraform_version": "1.1.7",
"serial": 1,
"lineage": "921cfa36-9ad5-9a2e-66db-d2ef62e7509b",
"outputs": {},
"resources": [
{
"mode": "managed",
"type": "local_file",
"name": "foo",
"provider": "provider[\"registry.terraform.io/hashicorp/local\"]",
"instances": [
{
"schema_version": 0,
"attributes": {
"content": "This is a text content of the foo file!",
"content_base64": null,
"directory_permission": "0777",
"file_permission": "0777",
"filename": "/home/bojan/dev/github/demo-terraform/local_resources_demo/temp/foo.txt",
"id": "db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e",
"sensitive_content": null,
"source": null
},
"sensitive_attributes": [],
"private": "bnVsbA=="
}
]
}
]
}
terraform show
# local_file.foo:
resource "local_file" "foo" {
content = "This is a text content of the foo file!"
directory_permission = "0777"
file_permission = "0777"
filename = "/home/bojan/dev/github/demo-terraform/local_resources_demo/temp/foo.txt"
id = "db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e"
}
Updating already created resources
resource "local_file" "foo" {
filename = "${path.cwd}/temp/foo.txt"
content = "This is a text content of the foo file!"
}
local_file.foo: Refreshing state... [id=db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e]
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
-/+ destroy and then create replacement
Terraform will perform the following actions:
# local_file.foo must be replaced
-/+ resource "local_file" "foo" {
~ file_permission = "0777" -> "0700" # forces replacement
~ id = "db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e" -> (known after apply)
# (3 unchanged attributes hidden)
}
Plan: 1 to add, 0 to change, 1 to destroy.
Note: You didn't use the -out option to save this plan, so Terraform can't guarantee to take exactly these actions if you run "terraform apply" now.
local_file.foo: Refreshing state... [id=db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e]
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
-/+ destroy and then create replacement
Terraform will perform the following actions:
# local_file.foo must be replaced
-/+ resource "local_file" "foo" {
~ file_permission = "0777" -> "0700" # forces replacement
~ id = "db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e" -> (known after apply)
# (3 unchanged attributes hidden)
}
Plan: 1 to add, 0 to change, 1 to destroy.
Do you want to perform these actions?
Terraform will perform the actions described above.
Only 'yes' will be accepted to approve.
Enter a value: yes
local_file.foo: Destroying... [id=db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e]
local_file.foo: Destruction complete after 0s
local_file.foo: Creating...
local_file.foo: Creation complete after 0s [id=db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e]
Apply complete! Resources: 1 added, 0 changed, 1 destroyed.
total 12
-rwx------ 1 bojan bojan 39 Mar 28 16:17 foo.txt
Deleting resources
local_file.foo: Refreshing state... [id=db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e]
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
- destroy
Terraform will perform the following actions:
# local_file.foo will be destroyed
- resource "local_file" "foo" {
- content = "This is a text content of the foo file!" -> null
- directory_permission = "0777" -> null
- file_permission = "0700" -> null
- filename = "/home/bojan/dev/github/demo-terraform/local_resources_demo/temp/foo.txt" -> null
- id = "db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e" -> null
}
Plan: 0 to add, 0 to change, 1 to destroy.
Do you really want to destroy all resources?
Terraform will destroy all your managed infrastructure, as shown above.
There is no undo. Only 'yes' will be accepted to confirm.
Enter a value: yes
local_file.foo: Destroying... [id=db5ca40b5588d44e9ec6c1b4005e11a6fd0c910e]
local_file.foo: Destruction complete after 0s
Destroy complete! Resources: 1 destroyed.
Configuration Directory
- main.tf - main config file containing definition of resources
- variables.tf - contains variable declarations
- outputs.tf - contains outputs from resources
- provider.tf - contains provider definitions
Debugging (Logging)
- INFO
- WARNING
- ERROR
- DEBUG
- TRACE (most verbose)
- set TF_LOG_PATH environment variable to a path to the log file
- make sure that TF_LOG is set