terraform 0.12upgrade command

The terraform 0.12upgrade command applies several automatic upgrade rules to help prepare a module that was written for Terraform v0.11 to be used with Terraform v0.12.

Usage

Usage: terraform 0.12upgrade [options] [dir]

By default, 0.12upgrade changes configuration files in the current working directory. However, you can provide an explicit path to another directory if desired, which may be useful for automating migrations of several modules in the same repository.

When run with no other options, the command will first explain what it is going to do and prompt for confirmation:

$ terraform 0.12upgrade
 
This command will rewrite the configuration files in the given directory so
that they use the new syntax features from Terraform v0.12, and will identify
any constructs that may need to be adjusted for correct operation with
Terraform v0.12.
 
We recommend using this command in a clean version control work tree, so that
you can easily see the proposed changes as a diff against the latest commit.
If you have uncommitted changes already present, we recommend aborting this
command and dealing with them before running this command again.
 
Would you like to upgrade the module in the current directory?
  Only 'yes' will be accepted to confirm.
 
  Enter a value: yes

The 0.12upgrade subcommand requires access to providers used in the configuration in order to analyze their resource types, so it's important to run terraform init first to install these. In some rare cases, a configuration that worked in v0.11 may have syntax errors in v0.12, in which case terraform init will run in a special mode where it installs only enough to run the upgrade command, after which you can run terraform init again to complete initialization.

Many of the rewrite rules are completely automatic, but in some cases the tool cannot determine enough information from the configuration alone to make a decision, and so it will instead add a comment to the configuration for user review. All such comments contain the string TF-UPGRADE-TODO to make them easier to find.

After upgrading, the configuration will also be reformatted into the standard Terraform style and expressions rewritten to use the more-readable v0.12 syntax features.

We recommend running this command with a clean version control work tree so that you can use VCS tools to review the proposed changes, including any TF-UPGRADE-TODO comments, and make any revisions required before committing the change.

Once upgraded the configuration will no longer be compatible with Terraform v0.11 and earlier. When upgrading a shared module that is called from multiple configurations, you may need to fix existing configurations to a previous version to allow for a gradual upgrade. If the module is published via a Terraform registry, assign a new major version number to the upgraded module source to represent the fact that this is a breaking change for v0.11 callers. If a module is installed directly from a version control system such as Git, use specific revisions to control which version is used by which caller.

The command-line options are all optional. The available options are:

• -yes - Skip the initial introduction messages and interactive confirmation. Use this when running the command in batch from a script.

• -force - Override the heuristic that attempts to detect if a configuration is already written for v0.12 or later. Some of the transformations made by this command are not idempotent, so re-running against the same module may change the meanings of some expressions in the module.

Batch Usage

After you've experimented with the 0.12upgrade command in some confined situations, if you have a repository containing multiple modules you may wish to batch-upgrade them all and review them together. Recursive upgrades are not supported by the tool itself, but if you are on a Unix-style system you can achieve this using the find command as follows:

find . -name '*.tf' -printf "%h\n" | uniq | xargs -n1 terraform 0.12upgrade -yes

On Mac OS X, the find included with the system does not support the -printf argument. You can install GNU find using Homebrew in order to use that argument:

brew install findutils

Once installed, run the above command line using gfind instead of find.

Note that the above includes the -yes option to override the interactive prompt, so be sure you have a clean work tree before running it.

Because upgrading requires access to the configuration's provider plugins, all of the directories must be initialized with terraform init prior to running the above.