Plan output reading in Terraform - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to show the Terraform plan output.

Terraform

terraform [1]

Drag options to blanks, or click blank then click option'

Aplan

Bdestroy

Capply

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'apply' runs the changes instead of showing them.

Using 'destroy' deletes resources instead of planning.

Using 'init' initializes the working directory but does not show plan.

The terraform plan command shows the changes Terraform will make without applying them.

2fill in blank

medium

Complete the code to save the Terraform plan output to a file.

Terraform

terraform plan -out=[1]

Drag options to blanks, or click blank then click option'

Aplan.txt

Bstate.tf

Ctfplan

Doutput.json

Attempts:

3 left

💡 Hint

Common Mistakes

Using a .txt or .json extension is not standard for plan files.

Using 'state.tf' is incorrect as it relates to state files, not plans.

The -out option saves the plan to a file, commonly named tfplan.

3fill in blank

hard

Fix the error in the command to apply a saved Terraform plan.

Terraform

terraform [1] tfplan

Drag options to blanks, or click blank then click option'

Aplan

Bapply

Cinit

Ddestroy

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'plan' again only shows the plan, does not apply.

Using 'init' initializes but does not apply.

Using 'destroy' deletes resources instead of applying.

The terraform apply command applies the changes from a saved plan file.

4fill in blank

hard

Fill both blanks to output the Terraform plan in JSON format.

Terraform

terraform [1] [2]

Drag options to blanks, or click blank then click option'

Aplan

Bapply

C-json

Dformat

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'apply' instead of 'plan' will apply changes.

Using '-format' is not a valid Terraform option.

Use terraform plan -json to output the plan in JSON format.

5fill in blank

hard

Fill all three blanks to read and show the Terraform plan output file.

Terraform

terraform [1] [2] [3]

Drag options to blanks, or click blank then click option'

Ashow

B-json

Ctfplan

D-out

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-out' instead of '-json' will not format output as JSON.

Using 'apply' instead of 'show' will apply changes.

The command terraform show -json tfplan reads and displays the saved plan in JSON format.

Practice

1. What does the terraform plan command primarily show before applying changes?

easy

A. The current cost of your cloud resources

B. The changes Terraform will make to your infrastructure

C. The list of all Terraform providers installed

D. The history of previous Terraform apply commands

Solution

1. Step 1: Understand the purpose of terraform plan

   This command previews the changes Terraform will perform on your infrastructure without applying them.

2. Step 2: Compare options with command purpose

   Only The changes Terraform will make to your infrastructure correctly describes this preview of changes. Other options describe unrelated information.

3. Final Answer:

   The changes Terraform will make to your infrastructure -> Option B

4. Quick Check:

   Plan shows changes = B [OK]

Hint: Plan shows what changes will happen before apply [OK]

Common Mistakes:

• Confusing plan with apply
• Thinking plan shows costs
• Assuming plan shows provider list

2. In Terraform plan output, what does the symbol ~ indicate?

easy

A. Resource will be updated

B. Resource will be created

C. Resource will be deleted

D. Resource will be ignored

Solution

1. Step 1: Recall Terraform plan symbols

   The symbol ~ means a resource will be updated (changed in place).

2. Step 2: Match symbol to meaning

   + means create, - means delete, so ~ must mean update.

3. Final Answer:

   Resource will be updated -> Option A

4. Quick Check:

   ~ means update = A [OK]

Hint: Remember + create, ~ update, - delete symbols [OK]

Common Mistakes:

• Mixing up ~ with + or -
• Thinking ~ means delete
• Assuming ~ means no change

3. Given this Terraform plan output snippet:

  # aws_instance.web will be updated in-place
  ~ resource "aws_instance" "web" {
      instance_type = "t2.micro" -> "t2.small"
    }

What does this output mean?

medium

A. The instance type will change from t2.micro to t2.small

B. No changes will be made to the instance

C. The instance will be deleted and recreated

D. The instance will be created new

Solution

1. Step 1: Analyze the plan output details

   The symbol ~ shows an in-place update. The instance_type changes from "t2.micro" to "t2.small".

2. Step 2: Interpret the meaning

   This means the existing instance will be updated to the new type without deletion.

3. Final Answer:

   The instance type will change from t2.micro to t2.small -> Option A

4. Quick Check:

   ~ means update, instance_type changed = C [OK]

Hint: Look for ~ and arrow showing old -> new value [OK]

Common Mistakes:

• Thinking resource will be deleted
• Ignoring the arrow showing value change
• Assuming no change because resource exists

4. You see this Terraform plan output:

  # aws_s3_bucket.example will be deleted
  - resource "aws_s3_bucket" "example" {
      bucket = "my-bucket"
    }

But you want to keep the bucket. What should you do?

medium

A. Ignore the plan and continue

B. Remove the resource from your Terraform config

C. Run terraform apply immediately

D. Add lifecycle rule with prevent_destroy to the resource

Solution

1. Step 1: Understand the delete plan

   The plan shows the bucket will be deleted, but you want to keep it.

2. Step 2: Use lifecycle prevent_destroy

   Adding a lifecycle block with prevent_destroy = true stops accidental deletion.

3. Final Answer:

   Add lifecycle rule with prevent_destroy to the resource -> Option D

4. Quick Check:

   Use prevent_destroy to block deletes = A [OK]

Hint: Use lifecycle prevent_destroy to stop unwanted deletes [OK]

Common Mistakes:

• Removing resource causes deletion
• Applying plan deletes bucket
• Ignoring plan risks data loss

5. You run terraform plan and see:

  # aws_security_group.sg will be replaced
  - resource "aws_security_group" "sg" {
      name = "old-sg"
    }
  + resource "aws_security_group" "sg" {
      name = "new-sg"
    }

What does this mean and why does Terraform replace the resource instead of updating it?

hard

A. Terraform will fail because name change is not allowed

B. Terraform updates the resource in place changing the name

C. Terraform deletes and recreates because the name attribute is immutable

D. Terraform ignores the change because names can be duplicated

Solution

1. Step 1: Analyze the plan output for replacement

   The plan shows the resource will be deleted (-) and a new one created (+) with a different name.

2. Step 2: Understand why replacement occurs

   Some attributes like security group name are immutable, so Terraform must replace the resource to change them.

3. Final Answer:

   Terraform deletes and recreates because the name attribute is immutable -> Option C

4. Quick Check:

   Immutable attribute change causes replacement = D [OK]

Hint: Immutable attribute changes cause resource replacement [OK]

Common Mistakes:

• Thinking Terraform updates name in place
• Assuming name can be duplicated
• Believing plan will fail on name change