82 lines
3.4 KiB
Plaintext
82 lines
3.4 KiB
Plaintext
---
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page_title: Provider Metadata
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description: >-
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For advanced use cases, modules can provide some pre-defined metadata for
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providers.
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---
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# Provider Metadata
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In some situations it's beneficial for a provider to offer an interface
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through which modules can pass it information unrelated to the resources
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in the module, but scoped on a per-module basis.
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Provider Metadata allows a provider to declare metadata fields it expects,
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which individual modules can then populate independently of any provider
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configuration. While provider configurations are often shared between modules,
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provider metadata is always module-specific.
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Provider Metadata is intended primarily for the situation where an official
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module is developed by the same vendor that produced the provider it is
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intended to work with, to allow the vendor to indirectly obtain usage
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statistics for each module via the provider. For that reason, this
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documentation is presented from the perspective of the provider developer
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rather than the module developer.
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~> **Advanced Topic!** This page covers technical details
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of Terraform. You don't need to understand these details to
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effectively use Terraform. The details are documented here for
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module authors and provider developers working on advanced
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functionality.
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~> **Experimental Feature!** This functionality is still considered
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experimental, and anyone taking advantage of it should [coordinate
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with the Terraform team](https://github.com/hashicorp/terraform/issues/new)
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to help the team understand how the feature is being used and to make
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sure their use case is taken into account as the feature develops.
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## Defining the Schema
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Before a provider can receive information from a module, the provider
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must strictly define the data it can accept. You can do this by setting
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the `ProviderMeta` property on your `schema.Provider` struct. Its value
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functions similarly to the provider config: a map of strings to the
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`schema.Schema` describing the values those strings accept.
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## Using the Data
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When Terraform calls your provider, you can use the `schema.ResourceData`
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that your `Create`, `Read`, and `Update` functions already use to get
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access to the provider metadata being passed. First define a struct
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that matches your schema, then call the `GetProviderSchema` method on
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your `schema.ResourceData`, passing a pointer to a variable of that type.
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The variable will be populated with the provider metadata, and will return
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an error if there was an issue with parsing the data into the struct.
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## Specifying Data in Modules
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To include data in your modules, create a `provider_meta` nested block under
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your module's `terraform` block, with the name of the provider it's trying
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to pass information to:
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```hcl
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terraform {
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provider_meta "my-provider" {
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hello = "world"
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}
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}
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```
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The `provider_meta` block must match the schema the provider has defined.
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## Versioning Your Modules
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Any module taking advantage of this functionality must make sure that the
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provider metadata supplied matches the schema defined in the provider, and
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that the version of Terraform that is being run has support for the provider
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metadata functionality. It's therefore recommended that any module taking
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advantage of this functionality should specify a minimum Terraform version of
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0.13.0 or higher, and a minimum version of each of the providers it specifies
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metadata as the first version the schema being used was supported by the
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provider.
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