Google Cloud Storage

Google Cloud Storage (GCS) can be used as an origin server with your Fastly services once you set up and configure your GCS account and link it to a Fastly service. It can also be configured to use private content. This speeds up your content delivery and reduces your origin's workload and response times with the dedicated links between Google and Fastly's POPs.

Using GCS as an origin server

To make your GCS data available through Fastly, follow the steps below.

Setting up and configuring your GCS account

  1. Sign up for Google Cloud Storage.
  2. Create a bucket to store your origin's data. The Create a bucket window appears.

    Google Cloud Storage New Bucket window

  3. Fill out the Create a bucket fields as follows:
    • In the Name field, enter a name for your bucket (e.g., mybucket). You can also create a domain-named bucket (e.g., images.example.com), but you'll be required to verify your domain ownership using Google's Search Console, if you have not already done so. See the instructions on Google's website. Remember the name you type. You'll need it to connect your GCS bucket to your Fastly service.
    • In the Default storage class area, select Regional.
    • From the Regional location menu, select a location to store your content. Most customers select a region close to the interconnect location they specify for shielding.
  4. Click the Create button.

You should now add objects to your bucket and make them externally accessible by selecting the Public link checkbox next to each of the objects.

Adding your GCS bucket as an origin server

To add your GCS bucket as an origin server, follow the instructions for working with hosts. You'll add specific details about your origin server.

  1. In the Hosts field on the Origins page, enter the appropriate address for your Host using the format <BUCKET>.storage.googleapis.com. For example, if your bucket name is test123, your hostname would be test123.storage.googleapis.com.

For the initial Edit this host fields:

  • In the Name field, enter any descriptive name for your service (e.g., Google Cloud Storage).
  • In the Address field, enter the appropriate address for your Host using the format <BUCKET>.storage.googleapis.com. For example, if your bucket name is mybucket, your hostname would be mybucket.storage.googleapis.com.
    1. When you edit the Transport Layer Security (TLS) area information for your host:
  • Leave the Enable TLS? default set to Yes to secure the connection between Fastly and your origin.
  • In the Certificate hostname field, enter storage.googleapis.com.
  • Under the SNI hostname field, select the checkbox to Match the SNI hostname to the Certificate hostname. The hostname address you entered during Host creation appears.
    1. From the Shielding menu below the TLS area, select an interconnect location from the list of shielding locations.
    2. In the Override host field in the Advanced options area, enter an appropriate address for your Host (e.g., test123.storage.googleapis.com). You entered this information during Host creation.

Interconnect locations

Interconnect locations allow you to establish direct links with Google's network edge when you choose your shielding location. By selecting one of the locations listed in our developer documentation, your traffic will be carried across our interconnections with Google and you will be eligible to receive Google's CDN partner pricing discount. Most customers select the interconnect closest to their GCS bucket's region. Review our caveats of shielding and select an interconnect accordingly.

Setting the Cache-Control header for your GCS bucket

By default, GCS performs its own caching for publicly readable objects, which may complicate efforts to purge cache. To avoid potential problems, we recommend using the gsutil command line utility to set the Cache-Control header for one or more objects in your GCS bucket:

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gsutil setmeta -h "Cache-Control: no-store, max-age=86400" gs://<bucket>/*.html

Replace <bucket> in the example above with your GCS bucket's name. Note that no-store instructs GCS not to cache your content, while max-age=86400 instructs Fastly to cache your content for one day. See Google's documentation on the setmeta command for more information.

Changing the default TTL for your GCS bucket

If you want to change the default TTL for your GCS bucket, if at all, keep the following in mind:

  • Your GCS account controls the default TTL for your GCS content. GCS currently sets the default TTL to 3600 seconds. Changing the default TTL will not override the default setting in your GCS account.
  • To override the default TTL set by GCS from within the Fastly web interface, create a new cache setting and enter the TTL there.
  • To override the default TTL in GCS, download the gsutil tool and then change the Cache-Control headers to delete the default TTL or change it to an appropriate setting.

X-Http-Method-Override header behavior

GCS provides a unique functionality that allows clients to add a X-Http-Method-Override request header to override the request method being sent in the HTTP messages. For instance, a GET request with the X-Http-Method-Override: HEAD request header is treated as a HEAD request by GCS and returns a HEAD response (200 status code with an empty body).

This can cause unintended caching behavior, which is a security risk. For example, if an X-Http-Method-Override request header is received and an unexpected response is cached. In order to minimize this risk, we strongly recommend you unset the X-Http-Method-Override header in the vcl_recv subroutine as shown below:

unset req.http.X-Http-Method-Override;

Using GCS with private objects

To use Fastly with GCS private objects, be sure you've already made your GCS data available to Fastly by pointing to the right GCS bucket, then follow the steps below.

Setting up interoperable access

By default, GCS authenticates requests using OAuth2, which Fastly does not support. To access private objects on GCS, your project must have HMAC authentication enabled and interoperable storage access keys (an "Access Key" and "Secret" pair) created. Do this by following the steps below.

  1. Open the Google Cloud Platform console and select the appropriate project.
  2. Click Settings. The Settings appear with the Project Access controls highlighted.
  3. Click the Interoperability tab. The Interoperability API access controls appear.
  4. If you have not set up interoperability before, click Enable interoperability access.
  5. Click Make <PROJECT-ID> your default project for interoperable access. If that project already serves as the default project, that information appears instead.

    the interoperability tab

  6. Click Create a new key. An access key and secret code appear.

    the google cloud storage access key

  7. Save the access key and secret code that appear. You'll need these later when you're creating an authorization header.

Setting up Fastly to use GCS private content

To use GCS private content with Fastly, create two headers, a Date header (required Authorization Signature) and an Authorization header.

Creating a Date header

  1. Log in to the Fastly web interface.
  2. From the All services page, select the appropriate service. You can use the search box to search by ID, name, or domain.
  3. Click the Edit configuration button and then select the option to clone the active version. The Domains page appears.
  4. Click the Content link. The Content page appears.
  5. Click the Create header button. The Create a new header page appears.

    creating a date header via the new header page

  6. Fill out the Create a new header fields as follows:
    • In the Name field, enter Date.
    • From the Type menu, select Request, and from the Action menu, select Set.
    • In the Destination field, enter http.Date.
    • In the Source field, enter now.
    • From the Ignore if set menu, select No.
    • In the Priority field, enter 10.
  7. Click the Create button. A new Date header appears on the Content page. You will use this later within the Signature of the Authorization header.

Creating an Authorization header

  1. Click the Create header button again to create another new header. The Create a header page appears.

    creating an authorization header via the header page

  2. Fill out the Create a header fields as follows:
    • In the Name field, enter Authorization.
    • From the Type menu, select Request, and from the Action menu, select Set.
    • In the Destination field, enter http.Authorization.
    • From the Ignore if set menu, select No.
    • In the Priority field, enter 20.
  3. In the Source field, enter the header authorization information using the following format:

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      "AWS <access key>:" digest.hmac_sha1_base64("<GCS secret>", if(req.method == "HEAD", "GET", req.method) LF LF LF req.http.Date LF "/<GCS bucket name>" req.url.path)
    

    replacing <access key>, <GCS secret>, and <GCS bucket name> with the information you gathered before you began. For example:

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      "AWS GOOGQORE5WOJJHLXH6OD:" digest.hmac_sha1_base64("oQb0hdmaxFOc5UmC6F833Cde0+ghRSgsr7CCnX62", if(req.method == "HEAD", "GET", req.method) LF LF LF req.http.Date LF "/test123" req.url.path)
    
  4. Click the Create button. A new Authorization header appears on the Content page.
  5. Click the Activate button to deploy your configuration changes.

A detailed look at the Source field

So what's going on in the Source field of the Authorization header? Here's the basic format:

AWS<access key><signature function><key><message>

It tells us the following:

Element Description
AWS A constant placed before the access key. It's always AWS.
access key The access key ID from your GCS developer's account. We used GOOGQORE5WOJJHLXH6OD in this example.
signature function The algorithm used to validate the key and message of the signature. We used digest.hmac_sha1_base64(<key>, <message>) in this example.
key The secret key ID from your GCS developer's account. We used oQb0hdmaxFOc5UmC6F833Cde0+ghRSgsr7CCnX62 in this example.
message The UTF-8 encoding of the StringToSign. See the table below for a break down of each portion of the message.

The message that's part of the Source field in the Authorization header takes on this basic format:

<HTTP-verb><\n><Content-MD5>\n<Content-Type><\n><Date><\n><CanonicalExtensionHeaders><\n><CanonicalizedResource>

It tells us the following:

Element Description
HTTP-verb The REST verb. We use req.method in this example.
\n A newline indicator constant. It's always \n.
Content-MD5 The content-md5 header value, used as a message integrity check. It's often left blank. We use LF (line feed) in this example.
Content-Type The content-type header value, used to specify the MIME-type. It's often left blank. We use LFin this example.
Date The date and time stamp. We use req.http.Date (which we created first as a separate header in the steps above).
CanonicalExtensionHeaders The x-amz- or x-goog- headers, which customize your GCS implementation. It's often left blank. We use LF in this example.
CanonicalizedResource Your GCS resource path name. We're concatenating GCS bucket name "/test123" with object path req.url.path in this example.
This article describes an integration with a service provided by a third party. See our note on integrations for details.
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