registry/docs/storage-drivers/gcs.md

---
description: Explains how to use the Google Cloud Storage drivers
keywords: registry, service, driver, images, storage,  gcs, google, cloud
title: Google Cloud Storage driver
---

An implementation of the `storagedriver.StorageDriver` interface which uses Google Cloud for object storage.

## Parameters


<table>
  <thead>
    <tr>
      <th>Parameter</th>
      <th>Required</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>
        <code>bucket</code>
      </td>
      <td>
        yes
      </td>
      <td>
        Storage bucket name.
      </td>
    </tr>
    <tr>
      <td>
        <code>keyfile</code>
      </td>
      <td>
        no
      </td>
      <td>
        A private service account key file in JSON format. Instead of a key file <a href="https://developers.google.com/identity/protocols/application-default-credentials">Google Application Default Credentials</a> can be used.
      </td>
    </tr>
     <tr>
      <td>
        <code>rootdirectory</code>
      </td>
      <td>
        no
      </td>
      <td>
        This is a prefix that is applied to all Google Cloud Storage keys to allow you to segment data in your bucket if necessary.
      </td>
    </tr>
     <tr>
      <td>
        <code>chunksize</code>
      </td>
      <td>
        no (default 5242880)
      </td>
      <td>
        This is the chunk size used for uploading large blobs, must be a multiple of 256*1024.
      </td>
    </tr>
  </tbody>
</table>


`bucket`: The name of your Google Cloud Storage bucket where you wish to store objects (needs to already be created prior to driver initialization).

`keyfile`: (optional) A private key file in JSON format, used for [Service Account Authentication](https://cloud.google.com/storage/docs/authentication#service_accounts).

**Note** Instead of a key file you can use [Google Application Default Credentials](https://developers.google.com/identity/protocols/application-default-credentials).

`rootdirectory`: (optional) The root directory tree in which all registry files are stored. Defaults to the empty string (bucket root). If a prefix is used, the path `bucketname/<prefix>` has to be pre-created before starting the registry.