Auto-Init is a feature of Terragrunt that makes it so that
terragrunt init does not need to be called explicitly before other terragrunt commands.
When Auto-Init is enabled (the default), terragrunt will automatically call
terraform init during other commands (e.g.
terragrunt plan) when terragrunt detects that:
terraform init has never been called, or
source needs to be downloaded, or
the modules or remote state used by the module have changed since the previous call to
extra_arguments can be configured to allow customization of the
terraform init command.
Note that there might be cases where terragrunt does not properly detect that
terraform init needs be called. In this case, terraform would fail. Running
terragrunt init again corrects this situation.
For some use cases, it might be desirable to disable Auto-Init. For example, if each user wants to specify a different
-plugin-dir option to
terraform init (and therefore it cannot be put in
extra_arguments). To disable Auto-Init, use the
--terragrunt-no-auto-init command line option or set the
TERRAGRUNT_AUTO_INIT environment variable to
Disabling Auto-Init means that you must explicitly call
terragrunt init prior to any other terragrunt commands for a particular configuration. If Auto-Init is disabled, and terragrunt detects that
terraform init needs to be called, then terragrunt will fail.