How to fix Error: Invalid lifecycle argument in Terraform

Check your lifecycle block against the complete list of valid Terraform lifecycle arguments:

- create_before_destroy - boolean: Create new resource before destroying old one
- prevent_destroy - boolean: Prevent resource destruction
- ignore_changes - list or 'all': Ignore changes to specific attributes
- replace_triggered_by - list: Replace resource when dependent resource changes
- precondition - block: Check conditions before creating/updating resource
- postcondition - block: Check conditions after lifecycle operations
- action_trigger - block: Automatically invoke actions based on conditions

Correct example:

resource "aws_instance" "example" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"

  lifecycle {
    create_before_destroy = true
    prevent_destroy       = false
    ignore_changes        = [tags]
  }
}

Review your lifecycle block carefully for common typos:

Incorrect:

lifecycle {
  create_destroy = true          # Wrong: should be 'create_before_destroy'
  prevent_remove = true          # Wrong: should be 'prevent_destroy'
  ignore_change = ["tags"]       # Wrong: should be 'ignore_changes'
  replace_on = [aws_iam_role]    # Wrong: should be 'replace_triggered_by'
}

Correct:

lifecycle {
  create_before_destroy = true
  prevent_destroy       = true
  ignore_changes        = ["tags"]
  replace_triggered_by  = [aws_iam_role.example]
}

Ensure you're using the correct block syntax. The lifecycle block should use curly braces { }, not assignment with equals sign.

Incorrect:

resource "aws_instance" "example" {
  lifecycle = {
    prevent_destroy = true
  }
}

Correct:

resource "aws_instance" "example" {
  lifecycle {
    prevent_destroy = true
  }
}

The lifecycle block does not support variables, dynamic blocks, or conditional values. All lifecycle arguments must be static values.

Incorrect (not supported):

variable "prevent_destroy_enabled" {
  type = bool
}

resource "aws_instance" "example" {
  lifecycle {
    prevent_destroy = var.prevent_destroy_enabled  # Variables not allowed!
  }
}

Correct approach - use separate configurations or modules:

resource "aws_instance" "example" {
  lifecycle {
    prevent_destroy = true  # Must be a literal value
  }
}

Be careful not to confuse the lifecycle meta-argument with provider-specific lifecycle_policy arguments. Some AWS resources like S3 and EFS have their own lifecycle_policy arguments that are different from the Terraform lifecycle block.

Terraform lifecycle meta-argument (applies to all resources):

resource "aws_instance" "example" {
  lifecycle {
    prevent_destroy = true
  }
}

AWS-specific lifecycle_policy (for S3 buckets):

resource "aws_s3_bucket_lifecycle_configuration" "example" {
  bucket = aws_s3_bucket.example.id

  rule {
    id     = "rule1"
    status = "Enabled"
    expiration {
      days = 30
    }
  }
}

These are completely different features.

After making corrections, use Terraform's built-in validation command to catch syntax and argument errors early:

terraform validate

This command checks your configuration against Terraform's schema and will report any invalid arguments or syntax issues before you attempt to plan or apply.

If the validation passes, you can safely proceed to planning:

terraform plan