- The OpenTofu Language
- Providers
Providers
OpenTofu relies on plugins called providers to interact with cloud providers, SaaS providers, and other APIs.
OpenTofu configurations must declare which providers they require so that OpenTofu can install and use them. Additionally, some providers require configuration (like endpoint URLs or cloud regions) before they can be used.
What Providers Do
Each provider adds a set of resource types and/or data sources that OpenTofu can manage.
Every resource type is implemented by a provider; without providers, OpenTofu can't manage any kind of infrastructure.
Most providers configure a specific infrastructure platform (either cloud or self-hosted). Providers can also offer local utilities for tasks like generating random numbers for unique resource names.
Where Providers Come From
Providers are distributed separately from OpenTofu itself, and each provider has its own release cadence and version numbers.
The Public OpenTofu Registry is the main directory of publicly available providers, and hosts providers for most major infrastructure platforms.
Provider Documentation
Each provider has its own documentation, describing its resource types and their arguments. This documentation can be found in each provider's GitHub repository, and the documentation for many providers is also mirrored on the Providers index in the Public OpenTofu Registry.
Provider documentation is versioned, so it's important to refer to the tag or release matching the version you are using.
How to Use Providers
Providers are released separately from OpenTofu itself and have their own version numbers. In production we recommend constraining the acceptable provider versions in the configuration's provider requirements block, to make sure that tofu init
does not install newer versions of the provider that are incompatible with the configuration.
To use resources from a given provider, you need to include some information about it in your configuration. See the following pages for details:
-
Provider Requirements documents how to declare providers so OpenTofu can install them.
-
Provider Configuration documents how to configure settings for providers.
-
Dependency Lock File documents an additional HCL file that can be included with a configuration, which tells OpenTofu to always use a specific set of provider versions.
Provider Installation
-
TACOS (TF Automation and Collaboration Software) install providers as part of every run.
-
OpenTofu CLI finds and installs providers when initializing a working directory. It can automatically download providers from a provider registry, or load them from a local mirror or cache. If you are using a persistent working directory, you must reinitialize whenever you change a configuration's providers.
To save time and bandwidth, OpenTofu CLI supports an optional plugin cache. You can enable the cache using the
plugin_cache_dir
setting in the CLI configuration file.
To ensure OpenTofu always installs the same provider versions for a given configuration, you can use OpenTofu CLI to create a dependency lock file and commit it to version control along with your configuration. If a lock file is present, OpenTofu CLI, and TACOS (TF Automation and Collaboration Software) will all obey it when installing providers.
How to Find Providers
To find providers for the infrastructure platforms you use, browse the Public OpenTofu Registry.
Some providers on the Registry are developed and published by HashiCorp, some are published by platform maintainers, and some are published by users and volunteers.
How to Develop Providers
Providers are written in Go, using the Terraform Plugin SDK. For more information on developing providers, see the Plugin Development documentation.
Running Acceptance Tests with OpenTofu CLI
When testing with OpenTofu, additional steps are required to run acceptance tests against the OpenTofu CLI. Set the following environment variables before running your acceptance tests: