Terraform fmt for formatting - Step-by-Step Execution

Process Flow - Terraform fmt for formatting

Write Terraform code

↓

Run 'terraform fmt'

↓

Terraform scans files

↓

Detect formatting issues?

No→Exit, files unchanged

Yes↓

Rewrite files with standard format

↓

Exit, files formatted

Terraform fmt checks your code files and rewrites them to follow standard formatting rules, making your code neat and consistent.

Execution Sample

Terraform

terraform fmt

Runs the formatter on Terraform files in the current directory to fix indentation and spacing.

Process Table

Step	Action	Files Checked	Formatting Issues Found	Files Changed
1	Start terraform fmt	main.tf, variables.tf	No	No
2	Check main.tf	main.tf	Yes	Yes
3	Rewrite main.tf with standard format	main.tf	N/A	Yes
4	Check variables.tf	variables.tf	No	No
5	Finish formatting	main.tf, variables.tf	N/A	Yes

💡 All files checked; main.tf reformatted; variables.tf unchanged.

Status Tracker

Variable	Start	After Step 2	After Step 3	Final
main.tf content	Unformatted code	Unformatted code	Formatted code	Formatted code
variables.tf content	Formatted code	Formatted code	Formatted code	Formatted code

Key Moments - 2 Insights

Why does terraform fmt sometimes not change any files?

If the files are already formatted correctly, terraform fmt finds no issues and leaves them unchanged, as shown in step 1 and 4 of the execution table.

Does terraform fmt change the code logic or only formatting?

Terraform fmt only changes spacing and indentation, not the code logic or content, as seen in the variable_tracker where content changes only reflect formatting.

Visual Quiz - 3 Questions

Look at the execution table, at which step does terraform fmt rewrite a file?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Check the 'Action' and 'Files Changed' columns in the execution table.

According to the variable tracker, what is the state of variables.tf after formatting?

A Deleted file

B Unformatted code

C Formatted code

D Partially formatted code

💡 Hint

Look at the 'variables.tf content' row in the variable_tracker after final step.

If main.tf was already formatted, how would the execution table change?

A Step 3 would be skipped with no files changed

B Step 2 would show formatting issues found

C Step 4 would rewrite variables.tf

D Step 5 would show files deleted

💡 Hint

Refer to the 'Formatting Issues Found' and 'Files Changed' columns in the execution table.

Concept Snapshot

terraform fmt
- Command to format Terraform files
- Fixes indentation and spacing
- Does not change code logic
- Runs in current directory by default
- Keeps code neat and consistent

Full Transcript

Terraform fmt is a command that checks your Terraform code files for formatting issues like indentation and spacing. When you run terraform fmt, it scans all Terraform files in the current folder. If it finds files that are not formatted properly, it rewrites them to follow the standard style. If files are already formatted, it leaves them unchanged. This helps keep your code clean and easy to read without changing how it works.

Practice

1. What is the main purpose of the terraform fmt command?

easy

A. To check for syntax errors in Terraform files

B. To deploy infrastructure to the cloud

C. To automatically format Terraform configuration files for readability

D. To destroy all Terraform-managed resources

Solution

1. Step 1: Understand the role of terraform fmt

   This command is designed to clean up and standardize the formatting of Terraform files, making them easier to read and maintain.

2. Step 2: Differentiate from other commands

   Unlike commands that deploy or destroy resources, terraform fmt only changes the file layout without affecting infrastructure.

3. Final Answer:

   To automatically format Terraform configuration files for readability -> Option C

4. Quick Check:

   Formatting = Readability [OK]

Hint: Remember: fmt = format code, not deploy or destroy [OK]

Common Mistakes:

• Confusing fmt with terraform apply
• Thinking fmt checks syntax errors
• Assuming fmt manages resources

2. Which of the following is the correct way to run terraform fmt on all files in the current directory?

easy

A. terraform fmt

B. terraform fmt -recursive

C. terraform fmt -all

D. terraform fmt --format-all

Solution

1. Step 1: Recall default behavior of terraform fmt

   By default, running terraform fmt without flags formats all Terraform files in the current directory.

2. Step 2: Check other options

   Options like -recursive exist to format subdirectories, but -all and --format-all are invalid flags.

3. Final Answer:

   terraform fmt -> Option A

4. Quick Check:

   Default fmt formats current directory [OK]

Hint: No flags needed to format current folder files [OK]

Common Mistakes:

• Using invalid flags like -all or --format-all
• Confusing recursive flag with default behavior
• Expecting fmt to format files outside current directory by default

3. Given this Terraform snippet before formatting:

resource "aws_instance" "example" {
ami = "ami-123456"
instance_type= "t2.micro"
}

What will terraform fmt do to this code?

medium

A. Add comments explaining each line

B. Add spaces around the equals sign and indent the block properly

C. Remove the resource block entirely

D. Change the resource type to "aws_server"

Solution

1. Step 1: Identify formatting issues

   The snippet lacks spaces around the equals sign and proper indentation inside the resource block.

2. Step 2: Understand what terraform fmt fixes

   It adds spaces around operators and indents blocks correctly but does not change resource types or add comments.

3. Final Answer:

   Add spaces around the equals sign and indent the block properly -> Option B

4. Quick Check:

   Fmt fixes spacing and indentation [OK]

Hint: Fmt fixes spacing and indentation, not content [OK]

Common Mistakes:

• Thinking fmt changes resource types
• Expecting fmt to add comments
• Assuming fmt deletes code blocks

4. You ran terraform fmt but your Terraform files still look messy. What is the most likely reason?

medium

A. Terraform fmt does not change file formatting

B. Terraform fmt only works on .tfvars files

C. Your files have syntax errors preventing formatting

D. You ran terraform fmt in the wrong directory

Solution

1. Step 1: Check where terraform fmt runs

   The command formats files in the current directory by default, so running it elsewhere won't affect your target files.

2. Step 2: Eliminate other options

   Terraform fmt does change formatting, works on .tf files, and does not require syntax correctness to format.

3. Final Answer:

   You ran terraform fmt in the wrong directory -> Option D

4. Quick Check:

   Run fmt where files are located [OK]

Hint: Run fmt in folder with your Terraform files [OK]

Common Mistakes:

• Assuming fmt fixes syntax errors
• Thinking fmt works on .tfvars files only
• Expecting fmt to format files outside current folder

5. You want to ensure all Terraform files in your project and all subfolders are formatted consistently before committing code. Which command should you use?

hard

A. terraform fmt -recursive

B. terraform fmt -all

C. terraform fmt --check

D. terraform fmt --init

Solution

1. Step 1: Understand recursive formatting

   The -recursive flag tells terraform fmt to format files in the current directory and all subdirectories.

2. Step 2: Review other options

   -all and --init are invalid flags; --check only verifies formatting without changing files.

3. Final Answer:

   terraform fmt -recursive -> Option A

4. Quick Check:

   Recursive flag formats all folders [OK]

Hint: Use -recursive to format all subfolders [OK]

Common Mistakes:

• Using invalid flags like -all
• Confusing --check with formatting action
• Trying to use --init for formatting