Auto-retry

Auto-Retry

Auto-Retry is a feature of terragrunt that will automatically address situations where a tofu/terraform command needs to be re-run.

OpenTofu/Terraform can fail with transient errors which can be addressed by simply retrying the command again. In the event terragrunt finds one of these errors, the command will be re-run again automatically.

Example

$ terragrunt apply
...
Initializing provider plugins...
- Checking for available provider plugins on https://releases.hashicorp.com...
Error installing provider "template": error fetching checksums: Get https://releases.hashicorp.com/terraform-provider-template/1.0.0/terraform-provider-template_1.0.0_SHA256SUMS: net/http: TLS handshake timeout.

Terragrunt sees this error, and knows it is a transient error that can be addressed by re-running the apply command.

Terragrunt has a small list of default known errors built-in. You can override these defaults with your own custom retryable errors in your terragrunt.hcl configuration:

retryable_errors = [
  "a regex to match the error",
  "another regex"
]

E.g:

retryable_errors = [
  "(?s).*Error installing provider.*tcp.*connection reset by peer.*",
  "(?s).*ssh_exchange_identification.*Connection closed by remote host.*"
]

By default, auto-retry tries a maximum of three times to re-run a command, pausing for five seconds between each retry, at which point it will deem the error as not transient, and accept the tofu/terraform failure. However, you can override these defaults. For example, the following retries up to five times, with 60 seconds in between each retry:

retry_max_attempts = 5
retry_sleep_interval_sec = 60

To disable auto-retry, use the --terragrunt-no-auto-retry command line option or set the TERRAGRUNT_NO_AUTO_RETRY environment variable to true.