Ignore Secret Rotation

Adds ignore_changes for the database credential attribute on RDS instances and Aurora clusters. A rotated or regenerated password stops showing as a diff on every plan.

Why this rule exists

A regenerated random_password, a rotated Secrets Manager or Vault data source, or a variable supplied differently per runner gives Terraform a new value on every plan. Each plan proposes resetting the database password, and an apply that goes through resets it for real.

The fix is ignore_changes on the credential attribute, and a lifecycle block cannot be passed into an upstream module as a variable.

Related Terraform and OpenTofu issues

Limitations this rule answers

Per-module pages under Workarounds where this rule is the answer, each with the native workaround first and the diff the rule makes:

• RDS: Terraform wants to reset the database password on every plan

Affected resources

What this rule does

Adds a lifecycle { ignore_changes = [...] } block to each matching resource. Terraform and OpenTofu will ignore external changes to the listed attributes on subsequent plans.

Ignored attributes: password Adds a lifecycle { ignore_changes = [...] } block to each matching resource. Terraform and OpenTofu will ignore external changes to the listed attributes on subsequent plans.

Ignored attributes: master_password

Before and after

Before (upstream module):

resource "aws_db_instance" "this" {
  # ... resource configuration ...

  tags = var.tags
}

After (with Ignore Secret Rotation applied):

resource "aws_db_instance" "this" {
  # ... resource configuration ...

  tags = var.tags

  lifecycle {
    ignore_changes = [password]
  }
}

Before (upstream module):

resource "aws_db_instance" "this" {
  # ... resource configuration ...

  tags = var.tags
}

After (with Ignore Secret Rotation applied):

resource "aws_db_instance" "this" {
  # ... resource configuration ...

  tags = var.tags

  lifecycle {
    ignore_changes = [master_password]
  }
}

The only change is the rule transformation. All existing arguments, outputs, and module behavior remain identical.

The example above is illustrative. To see this rule run for real, open it in the Rules Playground — it applies lifecycle_ignore_secret_rotation to a reviewed upstream module that actually declares the resources this rule targets, and shows the diff the registry would serve. No account needed.

Known limits

• Only password on aws_db_instance and master_password on aws_rds_cluster. Other engines and resources are not touched.
• Does not rotate anything and does not manage the secret. It only stops Terraform from writing the attribute back.
• Each attribute list is a parameter; an organization can set one to [] to contribute nothing for that resource type.
• Only .tf and .tofu files are read. Modules written in JSON syntax (.tf.json, .tofu.json) are left untouched.
• Only the module's own directory and its first-level modules/* submodules are processed. Modules that this module calls by source URL are separate downloads and are handled on their own request.

Default configuration

These are the values the rule ships with. They are not settable from a module source URL: ?rules= carries rule names only, so a per-request enable uses exactly the defaults below. Your organization sets them per rule, in its Baseline or in a ruleset, from the Operational Rules page; see Baseline rules and rulesets.

The rule's definition

The HCL this rule is written in - its parameters, their shipped defaults, and the transformers it runs - is published at lifecycle_ignore_secret_rotation, alongside every other selectable rule.

How to enable

On a framework host, per request:

Add ?rules=lifecycle_ignore_secret_rotation to your HTTPS module source, using the id exactly as written.

module "example" {
  source = "https://soc2.compliance.tf/terraform-aws-modules/s3-bucket/aws?version=5.0.0&rules=lifecycle_ignore_secret_rotation"
}

A ?rules= list is either all bare names, which replace your organization's rules for that download, or all - prefixed names, which subtract from them. Mixing the two is refused with a 400 rather than silently treated as a replacement. To add this rule on top of your organization's rules instead, use ?add_rules=lifecycle_ignore_secret_rotation; a bare ?rules= list cannot be combined with it, because a bare list already replaced the set there was something to add to.

The + add prefix was removed. It reached the registry only when written %2B, and a literal + in a query string decodes to a space everywhere, so ?rules=+lifecycle_ignore_secret_rotation arrived as a bare name with a leading space — one step from silently replacing your organization's rules. Any +, in either spelling, is now a 400 naming ?add_rules=.

On your organization's host:

Add the rule to the organization's Baseline, which applies to every module served from the bare organization form <alias>.compliance.tf/<namespace>/<name>/<provider>, or to a named ruleset that one module selects with ?ruleset=<name> on the HTTPS form of that address. A project environment (<alias>.compliance.tf/<project>/<env>/<module>) serves the rules frozen in its bound snapshot instead: there the rule goes into the config draft and reaches the environment by promotion. On both organization forms ?rules= and ?add_rules= are refused with a 400 — including the subtractive - prefix — rather than dropped, so you cannot mistake an ignored override for an applied one. Change the configuration, not the URL. See Baseline rules and rulesets for the configuration flow, and registry resolution for how the address forms differ.

Break-glass path

On a framework host, add ?rules=-lifecycle_ignore_secret_rotation to the module source URL and run terraform init -upgrade to fetch a copy without this rule. The copy in .terraform/modules/ stays until the next upgrade, so remove the override when you are done. On your organization's host the parameter is refused with a 400 rather than ignored. The rule comes from the organization's configuration: a Baseline rule applies to every module served from the bare organization form, so an admin disables it for the duration of the operation, or keeps it out of the Baseline and in a ruleset that only the modules needing it select. On a project environment the posture is the bound snapshot and its waivers. See Baseline rules and rulesets.

Failure modes