- release_tracks: [ALPHA, BETA, GA]

  help_text:
    brief: Set the IAM policy for a Cloud Spanner instance.
    description: |
      Set the IAM policy for a Cloud Spanner instance given a instance ID and
      a file encoded in JSON or YAML that contains the IAM policy.
    examples: |
      The following command reads an IAM policy defined in a JSON file
      `policy.json` and sets it for a spanner instance with the ID
      `example-instance`:

        $ {command} example-instance policy.json

      See https://cloud.google.com/iam/docs/managing-policies for details of the
      policy file format and contents.
  request:
    collection: spanner.projects.instances

  arguments:
    resource:
      help_text: The Spanner instance to set the IAM policy for.
      spec: !REF googlecloudsdk.command_lib.spanner.resources:instance

  iam:
    policy_version: 3