Local state behavior in Terraform - Step-by-Step Execution

Process Flow - Local state behavior

Terraform Init

↓

First terraform apply

↓

Local State File Created

↓

Subsequent Runs Read Local State

↓

Detect Changes & Plan

↓

Apply Changes & Update State

↓

Repeat

Terraform initializes with 'terraform init'. The first 'terraform apply' creates the local state file. Subsequent runs read and update this file locally to detect changes and plan updates.

Execution Sample

Terraform

terraform init
terraform apply
terraform apply

Initialize Terraform, apply resources creating local state, then apply again to detect no changes.

Process Table

Step	Action	State File Exists?	State Content	Result
1	terraform init	No	None	Terraform initialized (.terraform directory created), no state file created
2	terraform apply (first)	No	None	Resources created, state file created with resource info
3	terraform apply (second)	Yes	Has resource info	No changes detected, nothing applied

💡 No changes detected on second apply, so execution stops.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3
local_state_file	None	None	Created with resource data	Unchanged, contains resource data

Key Moments - 2 Insights

Why does Terraform not recreate resources on the second apply?

Because the local state file already has the resource info from the first apply (see execution_table step 3), Terraform knows the resources exist and skips creation.

What happens if the local state file is deleted before the second apply?

Terraform will think no resources exist and try to recreate them, since it has no local record (local_state_file variable would be None).

Visual Quiz - 3 Questions

Look at the execution table, what is the state content after the first terraform apply?

A None

B Has resource info

C Empty

D Corrupted

💡 Hint

Check the 'State Content' column in row 2 of the execution_table.

At which step does the local state file get created?

A Step 3

B Step 1

C Step 2

D Before Step 1

💡 Hint

Look at the 'State File Exists?' column in the execution_table for step 2.

If the local state file is deleted after step 2, what will happen on the next apply?

A Terraform will detect no changes and do nothing

B Terraform will recreate all resources

C Terraform will fail with an error

D Terraform will update the state file without changes

💡 Hint

Refer to key_moments explanation about missing local state file.

Concept Snapshot

Terraform local state behavior:
- terraform init initializes working directory
- First terraform apply creates local state file with resource info
- Subsequent applies read local state to detect changes
- No changes means no resource recreation
- Deleting local state causes Terraform to lose track of resources

Full Transcript

Terraform uses a local state file to keep track of resources it manages. 'terraform init' initializes the working directory but does not create the state file. The first 'terraform apply' creates resources and the local state file with their details. On the second 'terraform apply', Terraform reads the local state file, sees the resources already exist, and detects no changes, so it does nothing. If the local state file is deleted, Terraform will think no resources exist and try to recreate them on the next apply.

Practice

1. What does Terraform's local state file primarily store?

easy

A. Information about resources Terraform manages on your computer

B. User credentials for cloud providers

C. Terraform configuration files

D. Logs of Terraform commands executed

Solution

1. Step 1: Understand Terraform state purpose

   The state file keeps track of resources Terraform creates or manages.

2. Step 2: Identify local state file role

   Local state stores this info on your computer for Terraform to know current resource status.

3. Final Answer:

   Information about resources Terraform manages on your computer -> Option A

4. Quick Check:

   Local state = resource info stored locally [OK]

Hint: Local state stores resource info on your PC, not configs or logs [OK]

Common Mistakes:

• Confusing state file with configuration files
• Thinking state stores user credentials
• Assuming state file contains command logs

2. Which of the following is the correct way to specify a local state file path in Terraform CLI?

easy

A. terraform apply -state-file=./myterraform.tfstate

B. terraform apply --state-file ./myterraform.tfstate

C. terraform apply --state ./myterraform.tfstate

D. terraform apply -state=./myterraform.tfstate

Solution

1. Step 1: Recall Terraform CLI syntax for state file

   The correct flag to specify state file path is '-state=path'.

2. Step 2: Match the correct option

   terraform apply -state=./myterraform.tfstate uses '-state=./myterraform.tfstate' which is valid syntax.

3. Final Answer:

   terraform apply -state=./myterraform.tfstate -> Option D

4. Quick Check:

   Use '-state=' flag to specify local state file [OK]

Hint: Use '-state=' flag to set local state file path [OK]

Common Mistakes:

• Using '--state-file' which is invalid
• Using '--state' without '=' sign
• Confusing flag names

3. Given this Terraform command sequence on a local state setup:

terraform init
terraform apply
terraform state rm aws_instance.example
terraform apply

What happens after the second terraform apply?

medium

A. Terraform deletes the aws_instance.example resource from the cloud

B. Terraform ignores aws_instance.example and makes no changes

C. Terraform recreates the aws_instance.example resource

D. Terraform throws an error about missing resource

Solution

1. Step 1: Understand 'terraform state rm' effect

   This command removes the resource from the state file but does not delete it in the cloud.

2. Step 2: Analyze second 'terraform apply'

   Terraform sees the resource missing in state, so it plans to create it again.

3. Final Answer:

   Terraform recreates the aws_instance.example resource -> Option C

4. Quick Check:

   Removing from state causes resource to be recreated [OK]

Hint: Removing resource from state makes Terraform recreate it [OK]

Common Mistakes:

• Thinking 'state rm' deletes resource in cloud
• Assuming Terraform ignores missing state entries
• Expecting an error on apply

4. You run Terraform with local state and get this error:
Error: Failed to load state: open terraform.tfstate: permission denied
What is the most likely cause and fix?

medium

A. The state file permissions prevent access; fix file permissions

B. The state file is locked by another process; wait and retry

C. The state file is corrupted; delete and reinitialize Terraform

D. Terraform version mismatch; upgrade Terraform to latest

Solution

1. Step 1: Interpret the error message

   'permission denied' means Terraform cannot read or write the state file due to OS permissions.

2. Step 2: Determine the fix

   Adjust file permissions to allow Terraform access to the state file.

3. Final Answer:

   The state file permissions prevent access; fix file permissions -> Option A

4. Quick Check:

   Permission denied = fix file permissions [OK]

Hint: Permission denied means fix file access rights [OK]

Common Mistakes:

• Assuming state file is locked by another process
• Deleting state file without backup
• Blaming Terraform version without checking permissions

5. You want to share your Terraform project with a teammate but keep using local state. What is the best practice to avoid state conflicts?

hard

A. Share the local state file directly via email or chat

B. Use a remote backend like Terraform Cloud or S3 for state storage

C. Each teammate runs Terraform independently with their own local state

D. Manually merge local state files before each apply

Solution

1. Step 1: Understand local state sharing risks

   Local state files are not designed for sharing; conflicts and overwrites can occur.

2. Step 2: Identify best practice for team collaboration

   Using a remote backend centralizes state and prevents conflicts.

3. Final Answer:

   Use a remote backend like Terraform Cloud or S3 for state storage -> Option B

4. Quick Check:

   Remote backend avoids local state conflicts in teams [OK]

Hint: Use remote backend to share state safely in teams [OK]

Common Mistakes:

• Sharing local state file directly causing conflicts
• Each teammate using separate local states causing drift
• Trying to manually merge state files