NAME
    gcloud alpha spanner backups update-metadata - updates the metadata of a
        Cloud Spanner a backup

SYNOPSIS
    gcloud alpha spanner backups update-metadata (BACKUP : --instance=INSTANCE)
        (--expiration-date=EXPIRATION_DATE
          | --retention-period=RETENTION_PERIOD) [GCLOUD_WIDE_FLAG ...]

DESCRIPTION
    (ALPHA) Updates the metadata of a Cloud Spanner a backup.

EXAMPLES
    To update the backup metadata with an exact expiration date, run:

        $ gcloud alpha spanner backups update-metadata BACKUP_ID \
            --instance=INSTANCE_NAME --expiration-date=2020-03-29T10:49:41Z

    To update the backup metadata with a retention period, run:

        $ gcloud alpha spanner backups update-metadata BACKUP_ID \
            --instance=INSTANCE_NAME --retention-period=2w

POSITIONAL ARGUMENTS
     Backup resource - The Cloud Spanner backup to update. The arguments in
     this group can be used to specify the attributes of this resource. (NOTE)
     Some attributes are not given arguments in this group but can be set in
     other ways.

     To set the project attribute:
      ◆ provide the argument backup on the command line with a fully
        specified name;
      ◆ provide the argument --project on the command line;
      ◆ set the property core/project.

     This must be specified.

       BACKUP
          ID of the backup or fully qualified identifier for the backup.

          To set the backup attribute:
          ▸ provide the argument backup on the command line.

          This positional argument must be specified if any of the other
          arguments in this group are specified.

       --instance=INSTANCE
          The name of the Cloud Spanner instance.

          To set the instance attribute:
          ▸ provide the argument backup on the command line with a fully
            specified name;
          ▸ provide the argument --instance on the command line;
          ▸ set the property spanner/instance.

REQUIRED FLAGS
     Exactly one of these must be specified:

       --expiration-date=EXPIRATION_DATE
          Expiration time of the backup, must be at least 6 hours and at most
          366 days from the time of creation. See $ gcloud topic datetimes for
          information on date/time formats.

       --retention-period=RETENTION_PERIOD
          Retention period of the backup relative from now, must be at least 6
          hours and at most a year from the time of creation. See $ gcloud
          topic datetimes for information on duration formats.

GCLOUD WIDE FLAGS
    These flags are available to all commands: --access-token-file, --account,
    --billing-project, --configuration, --flags-file, --flatten, --format,
    --help, --impersonate-service-account, --log-http, --project, --quiet,
    --trace-token, --user-output-enabled, --verbosity.

    Run $ gcloud help for details.

API REFERENCE
    This command uses the spanner/v1 API. The full documentation for this API
    can be found at: https://cloud.google.com/spanner/

NOTES
    This command is currently in alpha and might change without notice. If this
    command fails with API permission errors despite specifying the correct
    project, you might be trying to access an API with an invitation-only early
    access allowlist. These variants are also available:

        $ gcloud spanner backups update-metadata

        $ gcloud beta spanner backups update-metadata