Provisioner failure behavior in Terraform - Step-by-Step Execution

Process Flow - Provisioner failure behavior

Start Terraform Apply

↓

Create Resource

↓

Run Provisioner

↓

Provisioner Success?

No→Handle Failure

↓

Fail or Continue

↓

Resource Ready

↓

End

Terraform creates a resource, runs the provisioner, then checks if it succeeded. On failure, it either stops or continues based on settings.

Execution Sample

Terraform

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

  provisioner "local-exec" {
    command = "exit 1"
  }
}

This Terraform code creates an AWS instance and runs a local-exec provisioner that fails (exit 1).

Process Table

Step	Action	Provisioner Result	Behavior
1	Start terraform apply	N/A	Begin resource creation
2	Create aws_instance.example	N/A	Resource creation started
3	Run local-exec provisioner	Failure (exit 1)	Provisioner failed
4	Check failure handling	Failure detected	Terraform stops apply by default
5	Apply terminates	N/A	Resource creation rolled back

💡 Provisioner failed and Terraform stopped apply, rolling back resource creation

Status Tracker

Variable	Start	After Step 2	After Step 3	Final
Resource State	Not created	Creating	Provisioner failed	Rolled back
Provisioner Status	Not run	Not run	Failed	Failed

Key Moments - 2 Insights

Why does Terraform stop the apply when the provisioner fails?

By default, Terraform treats provisioner failure as a critical error and stops the apply to avoid inconsistent state, as shown in step 4 of the execution_table.

Can Terraform continue if a provisioner fails?

Yes, if you set 'on_failure = "continue"' in the provisioner block, Terraform will continue despite failure. This is not shown in the sample but changes behavior after step 4.

Visual Quiz - 3 Questions

Look at the execution_table, what is the provisioner result at step 3?

A Failure (exit 1)

B Success

C Not run

D Skipped

💡 Hint

Check the 'Provisioner Result' column at step 3 in the execution_table.

At which step does Terraform decide to stop the apply due to provisioner failure?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Look at the 'Behavior' column to see when Terraform stops, in step 4.

If 'on_failure = continue' was set, how would the behavior at step 4 change?

A Terraform would stop apply immediately

B Provisioner would not run

C Terraform would continue apply despite failure

D Resource creation would be skipped

💡 Hint

Refer to key_moments about continuing on provisioner failure.

Concept Snapshot

Terraform runs provisioners after resource creation.
If a provisioner fails, Terraform stops apply by default.
Use 'on_failure = continue' to continue despite failure.
Failure causes resource rollback to keep state consistent.

Full Transcript

Terraform applies start by creating resources. After creation, provisioners run to perform extra setup. If a provisioner fails, Terraform detects this failure and stops the apply process to avoid inconsistent infrastructure. This means the resource creation is rolled back. However, you can configure provisioners with 'on_failure = continue' to let Terraform continue even if the provisioner fails. This behavior ensures your infrastructure state remains reliable and predictable.