In some situations it's beneficial for a provider to offer an interface through which modules can pass it information unrelated to the resources in the module, but scoped on a per-module basis.
Provider Metadata allows a provider to declare metadata fields it expects, which individual modules can then populate independently of any provider configuration. While provider configurations are often shared between modules, provider metadata is always module-specific.
Provider Metadata is intended primarily for the situation where an official module is developed by the same vendor that produced the provider it is intended to work with, to allow the vendor to indirectly obtain usage statistics for each module via the provider. For that reason, this documentation is presented from the perspective of the provider developer rather than the module developer.
Before a provider can receive information from a module, the provider
must strictly define the data it can accept. You can do this by setting
the ProviderMeta
property on your schema.Provider
struct. Its value
functions similarly to the provider config: a map of strings to the
schema.Schema
describing the values those strings accept.
When Terraform calls your provider, you can use the schema.ResourceData
that your Create
, Read
, and Update
functions already use to get
access to the provider metadata being passed. First define a struct
that matches your schema, then call the GetProviderSchema
method on
your schema.ResourceData
, passing a pointer to a variable of that type.
The variable will be populated with the provider metadata, and will return
an error if there was an issue with parsing the data into the struct.
To include data in your modules, create a provider_meta
nested block under
your module's terraform
block, with the name of the provider it's trying
to pass information to:
terraform {
provider_meta "my-provider" {
hello = "world"
}
}
The provider_meta
block must match the schema the provider has defined.
Any module taking advantage of this functionality must make sure that the provider metadata supplied matches the schema defined in the provider, and that the version of Terraform that is being run has support for the provider metadata functionality. It's therefore recommended that any module taking advantage of this functionality should specify a minimum Terraform version of 0.13.0 or higher, and a minimum version of each of the providers it specifies metadata as the first version the schema being used was supported by the provider.