Import block syntax (Terraform 1.5+) - Step-by-Step Execution

Process Flow - Import block syntax (Terraform 1.5+)

Write import block

↓

Run terraform apply

↓

Terraform reads import block

↓

Terraform imports resource state

↓

Resource state linked to config

↓

Terraform plan shows no changes

↓

Done

The import block tells Terraform to link existing resources to the config during apply, so state is updated without manual CLI import.

Execution Sample

Terraform

import {
  id = "resource-id"
  to = aws_s3_bucket.example
}

This import block links an existing AWS S3 bucket with id 'resource-id' to the Terraform resource aws_s3_bucket.example.

Process Table

Step	Action	Input	Terraform Behavior	Result
1	Read import block	import { id = "resource-id" to = aws_s3_bucket.example }	Terraform parses import block	Import info stored for apply
2	terraform apply starts		Terraform prepares to import resource	Ready to import resource state
3	Import resource state	id = resource-id	Terraform fetches existing resource state	State linked to aws_s3_bucket.example
4	Update state file		Terraform updates local state with imported resource	State file now includes resource
5	Plan after import		Terraform compares config and state	No changes detected
6	Apply completes		Terraform finishes without creating or destroying	Resource managed by Terraform now
7	Exit	No more steps	Import process complete	Terraform state and config synced

💡 Import block processed, resource state linked, no further changes needed.

Status Tracker

Variable	Start	After Step 3	After Step 4	Final
import_block	Not read	Parsed with id and to	Used to fetch resource state	Processed and cleared
terraform_state	Empty for resource	Resource state fetched	State file updated	State synced with config

Key Moments - 3 Insights

Why doesn't Terraform create a new resource when using the import block?

Because the import block tells Terraform to link an existing resource by its ID, so Terraform updates the state instead of creating a new resource. See execution_table step 3 and 4.

What happens if the resource ID in the import block is incorrect?

Terraform will fail to fetch the resource state during apply (step 3), causing an error and stopping the import process.

Does the import block change the Terraform configuration files?

No, the import block only affects state linking during apply. The configuration remains the same. This is shown in step 5 where plan shows no changes.

Visual Quiz - 3 Questions

Look at the execution_table, at which step does Terraform link the existing resource state to the configuration?

A Step 2

B Step 3

C Step 5

D Step 6

💡 Hint

Check the 'Terraform Behavior' column for when resource state is fetched and linked.

According to variable_tracker, what is the state of terraform_state after step 4?

A Empty for resource

B Resource state fetched

C State file updated

D State synced with config

💡 Hint

Look at the 'terraform_state' row and the 'After Step 4' column.

If the import block is missing the 'to' attribute, what would happen during execution?

A Terraform would fail to parse the import block

B Terraform would import the resource anyway

C Terraform would create a new resource

D Terraform would skip the import silently

💡 Hint

Refer to execution_table step 1 where Terraform parses the import block.

Concept Snapshot

Import block syntax (Terraform 1.5+):
import {
  id = "resource-id"
  to = resource_type.resource_name
}
Use in config to link existing resources during terraform apply.
No manual CLI import needed.
Terraform updates state to manage resource without recreating.

Full Transcript

The import block in Terraform 1.5+ allows you to link existing cloud resources to your Terraform configuration automatically during terraform apply. You write an import block specifying the resource ID and the resource address in your config. When you run terraform apply, Terraform reads this block, fetches the existing resource state, and updates the local state file. This means Terraform now manages the resource without creating or destroying it. The plan after import shows no changes, confirming the resource is linked. If the import block is incorrect or missing required fields, Terraform will fail during parsing or import. This feature simplifies managing existing infrastructure by avoiding manual CLI import commands.

Practice

1. What is the main purpose of the import block in Terraform 1.5+?

easy

A. To create new resources automatically

B. To delete resources from the cloud provider

C. To let Terraform track existing resources without recreating them

D. To backup Terraform state files

Solution

1. Step 1: Understand the import block purpose

   The import block is designed to connect Terraform state with existing cloud resources.

2. Step 2: Differentiate from other actions

   It does not create or delete resources but tracks them to avoid recreation.

3. Final Answer:

   To let Terraform track existing resources without recreating them -> Option C

4. Quick Check:

   Import block = track existing resources [OK]

Hint: Import block links Terraform to existing resources [OK]

Common Mistakes:

• Thinking import creates new resources
• Confusing import with resource deletion
• Assuming import backs up state files

2. Which of the following is the correct syntax for an import block in Terraform 1.5+?

easy

A. import {
target = aws_instance.example
value = "i-1234567890abcdef0"
}

B. import {
to = aws_instance.example
id = "i-1234567890abcdef0"
}

C. import {
resource = aws_instance.example
key = "i-1234567890abcdef0"
}

D. import {
name = aws_instance.example
identifier = "i-1234567890abcdef0"
}

Solution

1. Step 1: Recall import block keys

   The import block uses to for the Terraform resource and id for the cloud resource ID.

2. Step 2: Match syntax with options

   Only import { to = aws_instance.example id = "i-1234567890abcdef0" } uses to and id correctly.

3. Final Answer:

   import { to = aws_instance.example id = "i-1234567890abcdef0" } -> Option B

4. Quick Check:

   Import keys = to and id [OK]

Hint: Remember keys: to = resource, id = cloud ID [OK]

Common Mistakes:

• Using wrong keys like resource or target
• Confusing id with identifier
• Missing quotes around the id value

3. Given this import block:

import {
  to = aws_s3_bucket.mybucket
  id = "my-existing-bucket"
}

What will Terraform do after applying this import block?

medium

A. Track the existing S3 bucket 'my-existing-bucket' without creating it

B. Create a new S3 bucket named 'my-existing-bucket'

C. Delete the S3 bucket 'my-existing-bucket'

D. Throw a syntax error due to missing resource configuration

Solution

1. Step 1: Understand import block effect

   The import block links Terraform state to an existing resource by its ID without creating or deleting it.

2. Step 2: Confirm behavior after import

   Terraform will track the existing bucket named 'my-existing-bucket' safely.

3. Final Answer:

   Track the existing S3 bucket 'my-existing-bucket' without creating it -> Option A

4. Quick Check:

   Import block = track existing resource [OK]

Hint: Import links state to existing resource, no creation [OK]

Common Mistakes:

• Assuming import creates new resources
• Thinking import deletes resources
• Confusing import with resource configuration

4. You wrote this import block:

import {
  to = aws_instance.web
  id = i-0abcd1234efgh5678
}

Terraform gives an error when applying. What is the likely cause?

medium

A. Terraform 1.5+ does not support import blocks

B. The to value should be the cloud resource ID

C. The import block must be inside a resource block

D. The id value is missing quotes

Solution

1. Step 1: Check syntax for id value

   The id value must be a string, so it requires quotes around it.

2. Step 2: Identify error cause

   Missing quotes around i-0abcd1234efgh5678 causes a syntax error.

3. Final Answer:

   The id value is missing quotes -> Option D

4. Quick Check:

   id value must be quoted string [OK]

Hint: Always quote id values in import blocks [OK]

Common Mistakes:

• Not quoting string IDs
• Confusing to and id values
• Placing import block inside resource block

5. You want to import an existing Azure resource group with ID "/subscriptions/123/resourceGroups/mygroup" into Terraform resource azurerm_resource_group.main. Which import block is correct and follows best practices?

hard

A. import {
to = azurerm_resource_group.main
id = "/subscriptions/123/resourceGroups/mygroup"
}

resource "azurerm_resource_group" "main" {
name = "mygroup"
location = "eastus"
}

B. import {
to = azurerm_resource_group.main
id = "mygroup"
}

resource "azurerm_resource_group" "main" {
name = "mygroup"
location = "eastus"
}

C. import {
to = azurerm_resource_group.main
id = "/subscriptions/123/resourceGroups/mygroup"
}

resource "azurerm_resource_group" "main" {
location = "eastus"
}

D. import {
to = azurerm_resource_group.main
id = "mygroup"
}

resource "azurerm_resource_group" "main" {
location = "eastus"
}

Solution

1. Step 1: Use full resource ID in import block

   The id must be the full Azure resource ID string to correctly identify the resource.

2. Step 2: Provide matching resource configuration

   After import, the resource block must include all required attributes like name and location to manage the resource safely.

3. Final Answer:

   Import block with full ID and resource block with name and location -> Option A

4. Quick Check:

   Full ID + matching config = correct import [OK]

Hint: Use full resource ID and matching config after import [OK]

Common Mistakes:

• Using partial ID instead of full resource ID
• Omitting required resource attributes after import
• Assuming import block replaces resource configuration