This document shows you how to create an
external Application Load Balancer
to route requests for static content to
Cloud Storage buckets. After you
configure a load balancer with the backend buckets, requests to URL paths that
begin with /love-to-fetch
are sent to the us-east1
Cloud Storage bucket, and all other requests are sent to the
europe-north1
Cloud Storage bucket, regardless of the user's region.
If your backends serve dynamic content over HTTP(S), consider using backend services instead of backend buckets.
If you are an existing user of the classic Application Load Balancer, make sure that you review Plan your migration to the global external Application Load Balancer when you plan a new deployment with the global external Application Load Balancer.Cloud Storage buckets as load balancer backends
An external Application Load Balancer uses a URL map to direct traffic from specified URL paths to your backends.
In the following diagram, the load balancer sends traffic with a path of
/love-to-fetch/
to a Cloud Storage bucket in the us-east1
region. All other requests go to a Cloud Storage bucket in the
europe-north1
region.
By default, Cloud Storage uses the same cache
that Cloud CDN uses. If you enable Cloud CDN on the backend
bucket, you can use Cloud CDN controls on your content.
Cloud CDN controls include, for example, cache modes, signed URLs, and
invalidation. Cloud CDN also lets you cache large content (> 10 MB). If
you don't enable Cloud CDN on your backend bucket, you can only use
origin Cache-Control
headers to control caching for smaller content, as set
by the Cloud Storage metadata.
Before you begin
Make sure that your setup meets the following prerequisites. If you are using
the gcloud storage
utility, you can install it by using instructions in
Discover object storage with the gcloud tool.
Set a default project
Console
- Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
-
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Google Cloud project.
-
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Google Cloud project.
gcloud
gcloud config set project PROJECT_ID
Replace PROJECT_ID
with the project that you are using for this guide.
Terraform
export GOOGLE_CLOUD_PROJECT=PROJECT_ID
Permissions
To follow this guide, you need to create Cloud Storage buckets and a load balancer in a project. You should be either a project owner or editor, or you should have the following Compute Engine IAM roles:
Task | Required Role |
---|---|
Create load balancer components | Network Admin |
Create Cloud Storage buckets | Storage Object Admin |
For more information, see the following guides:
Set up an SSL certificate resource
For an HTTPS load balancer, create an SSL certificate resource as described in the following documentation:
We recommend using a Google-managed certificate.
This example assumes that you already have an SSL certificate resource named
www-ssl-cert
.
Prepare your Cloud Storage buckets and content
The process for preparing your Cloud Storage buckets is as follows:
Create the buckets.
Copy content to the buckets.
Provide public access to the buckets.
Create Cloud Storage buckets
In this example, you create two Cloud Storage buckets for the load balancer to access. For production deployments, we recommend that you choose a multi-region bucket, which automatically replicates objects across multiple Google Cloud regions. This can improve the availability of your content and improve failure tolerance across your application.
Note the names of the Cloud Storage buckets you create, as they're used later. In this guide, they're referred to as BUCKET_1_NAME and BUCKET_2_NAME.
Console
In the Google Cloud console, go to the Cloud Storage Buckets page.
Click Create bucket.
In the Name your bucket box, enter a globally unique name that follows the naming guidelines.
Click Choose where to store your data.
Set Location type to Region.
Set Location to europe-north1. This is BUCKET_1_NAME in this guide.
Click Create.
Click Buckets to return to the Cloud Storage Buckets page. Use these instructions to create a second bucket, but set the Location to us-east1. This is BUCKET_2_NAME in this guide.
gcloud
gcloud storage buckets create gs://BUCKET_1_NAME --project=PROJECT_ID --default-storage-class=standard --location=europe-north1 --uniform-bucket-level-access
gcloud storage buckets create gs://BUCKET_2_NAME --project=PROJECT_ID --default-storage-class=standard --location=us-east1 --uniform-bucket-level-access
Replace BUCKET_1_NAME
and BUCKET_2_NAME
with the names of the buckets that you want to create.
Terraform
To create the buckets, use the google_storage_bucket
resource.
To learn how to apply or remove a Terraform configuration, see Basic Terraform commands.
Transfer content to your Cloud Storage buckets
So you can test the setup later, copy the following images from a public Cloud Storage bucket to your own Cloud Storage buckets.
gcloud
Click
Activate Cloud Shell.Run the following commands in Cloud Shell, replacing the bucket name variables with your Cloud Storage bucket names:
gcloud storage cp gs://gcp-external-http-lb-with-bucket/three-cats.jpg gs://BUCKET_1_NAME/never-fetch/
gcloud storage cp gs://gcp-external-http-lb-with-bucket/two-dogs.jpg gs://BUCKET_2_NAME/love-to-fetch/
Terraform
To copy items into the bucket, you can use the google_storage_bucket_object
resource.
Alternatively, use the null_resource
resource.
resource "null_resource" "upload_cat_image" { provisioner "local-exec" { command = "gcloud storage cp gs://gcp-external-http-lb-with-bucket/three-cats.jpg gs://${google_storage_bucket.bucket_1.name}/never-fetch/" } } resource "null_resource" "upload_dog_image" { provisioner "local-exec" { command = "gcloud storage cp gs://gcp-external-http-lb-with-bucket/two-dogs.jpg gs://${google_storage_bucket.bucket_2.name}/love-to-fetch/" } }
In the Google Cloud console, click Refresh on each bucket's details page to verify that the file has copied successfully.
Make your Cloud Storage buckets publicly readable
When you make Cloud Storage buckets publicly readable, anyone on the internet can list and view their objects, and view their metadata (excluding ACLs). Don't include sensitive information in your public buckets.
To reduce the likelihood of accidental exposure of sensitive information, don't store public objects and sensitive data in the same bucket.
Console
To grant all users access to view objects in your buckets, repeat the following procedure for each bucket:
In the Google Cloud console, go to the Cloud Storage Buckets page.
Click the bucket name, followed by the Permissions tab.
Click Add.
In the New principals box, enter
allUsers
.In the Select a role box, select Cloud Storage > Storage Object Viewer.
Click Save.
Click Allow public access.
gcloud
To grant all users access to view objects in your buckets, run the following commands:
gcloud storage buckets add-iam-policy-binding gs://BUCKET_1_NAME --member=allUsers --role=roles/storage.objectViewer
gcloud storage buckets add-iam-policy-binding gs://BUCKET_2_NAME --member=allUsers --role=roles/storage.objectViewer
Terraform
To grant all users access to view objects in your buckets, use the
google_storage_bucket_iam_member
resource and specify the allUsers
member.
Reserve an external IP address
After you've set up your Cloud Storage buckets, you can reserve a global static external IP address that your audience uses to reach your load balancer.
This step is optional but recommended, as a static external IP address provides a single address to point your domain at.
Console
In the Google Cloud console, go to the External IP addresses page.
Click Reserve static address.
In the Name box, enter
example-ip
.Set the Network Service Tier to Premium.
Set the IP version to IPv4.
Set the Type to Global.
Click Reserve.
gcloud
gcloud compute addresses create example-ip \ --network-tier=PREMIUM \ --ip-version=IPV4 \ --global
Note the IPv4 address that was reserved:
gcloud compute addresses describe example-ip \ --format="get(address)" \ --global
Terraform
To reserve an external IP address, use the
google_compute_global_address
resource.
Create an external Application Load Balancer with backend buckets
These instructions cover creating either an HTTP or HTTPS load balancer. To create an HTTPS load balancer you must add an SSL certificate resource to the load balancer's frontend. For more information, see the SSL certificates overview.
Console
Start your configuration
In the Google Cloud console, go to the Load balancing page.
- Click Create load balancer.
- For Type of load balancer, select Application Load Balancer (HTTP/HTTPS) and click Next.
- For Public facing or internal, select Public facing (external) and click Next.
- For Global or single region deployment, select Best for global workloads and click Next.
- For Load balancer generation, select Global external Application Load Balancer and click Next.
- Click Configure.
Basic configuration
- In the Name box, enter
http-lb
.
Configure the backend
Click Backend configuration.
Click the Backend services and backend buckets box, and then click Create a backend bucket.
In the Backend bucket name box, enter
cats
.In the Cloud Storage bucket box, click Browse.
Select BUCKET_1_NAME, and then click Select. Creating the
cats
backend bucket first makes it the default, where all unmatched traffic requests are directed. You can't change a default backend bucket's redirect rules in the load balancer.Click Create.
Use the same process to create a backend bucket named
dogs
, and select BUCKET_2_NAME.Click OK.
Configure routing rules
Routing rules determine how your traffic is directed. To configure routing, you'll set up host rules and path matchers, which are configuration components of an external Application Load Balancer's URL map. To set up the rules for this example:
- Click Routing rules.
- For
dogs
, enter*
in the Hosts field, and/love-to-fetch/*
in the Paths field.
Configure the frontend
Click Frontend configuration.
Verify that the following options are configured with these values:
Property Value (type a value or select an option as specified) Protocol HTTP Network Service Tier Premium IP version IPv4 IP address example-ip Port 80 Optional: HTTP keepalive timeout Enter a timeout value from 5 to 1200 seconds. The default value is 610 seconds. If you want to create an HTTPS load balancer instead of an HTTP load balancer, you must have an SSL certificate (
gcloud compute ssl-certificates list
), and you must fill in the fields as follows:Property Value (type a value or select an option as specified) Protocol HTTP(S) Network Service Tier Premium IP version IPv4 IP address example-ip Port 443 Optional: HTTP keepalive timeout Enter a timeout value from 5 to 1200 seconds. The default value is 610 seconds. Certificate Select the www-ssl-cert
certificate you created in the Set up an SSL certificate resource section, or create a new certificate.Optional: Enable HTTP to HTTPS Redirect Use this checkbox to enable redirects. Enabling this checkbox creates an additional partial HTTP load balancer that uses the same IP address as your HTTPS load balancer and redirects HTTP requests to your load balancer's HTTPS frontend.
This checkbox can only be selected when the HTTPS protocol is selected and a reserved IP address is used.
Click Done.
Review the configuration
Click Review and finalize.
Review the Frontend, Host and path rules, and Backend buckets.
Click Create and wait for the load balancer to be created.
Click the name of the load balancer (http-lb).
Note the IP address of the load balancer for the next task. In this guide, it's referred to as IP_ADDRESS.
gcloud
Configure the backend
gcloud compute backend-buckets create cats \ --gcs-bucket-name=BUCKET_1_NAME
gcloud compute backend-buckets create dogs \ --gcs-bucket-name=BUCKET_2_NAME
Configure the URL map
gcloud compute url-maps create http-lb \ --default-backend-bucket=cats
gcloud compute url-maps add-path-matcher http-lb \ --path-matcher-name=path-matcher-2 \ --new-hosts=* \ --backend-bucket-path-rules="/love-to-fetch/*=dogs" \ --default-backend-bucket=cats
Configure the target proxy
gcloud compute target-http-proxies create http-lb-proxy \ --http-keep-alive-timeout-sec=HTTP_KEEP_ALIVE_TIMEOUT_SEC \ --url-map=http-lb
Replace HTTP_KEEP_ALIVE_TIMEOUT_SEC
with the
client HTTP keepalive timeout
value from 5 to 1200 seconds. The default value is 610 seconds. This field is
optional.
Configure the forwarding rule
gcloud compute forwarding-rules create http-lb-forwarding-rule \ --load-balancing-scheme=EXTERNAL_MANAGED \ --network-tier=PREMIUM \ --address=example-ip \ --global \ --target-http-proxy=http-lb-proxy \ --ports=80
Terraform
To create the load balancer, use the following Terraform resources.
Configure the backend
To create the backend, use the google_compute_backend_bucket
resource.
Configure the URL map
To create the URL map, use the google_compute_url_map
resource.
Configure the target proxy
To create the target HTTP proxy, use the google_compute_target_http_proxy
resource.
Configure the forwarding rule
To create the forwarding rule, use the google_compute_global_forwarding_rule
resource.
NOTE: To change the mode to classic Application Load Balancer, set the load_balancing_scheme
attribute to
"EXTERNAL"
instead of "EXTERNAL_MANAGED"
.
To learn how to apply or remove a Terraform configuration, see Basic Terraform commands.
Send traffic to your load balancer
Several minutes after you have configured your load balancer, you can start sending traffic to the load balancer's IP address.
Console
The Google Cloud console isn't supported.
gcloud
Use the curl
command to test the response from the following URLs. Replace
IP_ADDRESS
with the load balancer's IPv4 address:
curl http://IP_ADDRESS/love-to-fetch/two-dogs.jpg
curl http://IP_ADDRESS/never-fetch/three-cats.jpg
Additional configuration
This section expands on the configuration example to provide alternative and additional configuration options. All of the tasks are optional. You can perform them in any order.
Update client HTTP keepalive timeout
The load balancer created in the previous steps has been configured with a default value for the client HTTP keepalive timeout.To update the client HTTP keepalive timeout, use the following instructions.
Console
In the Google Cloud console, go to the Load balancing page.
- Click the name of the load balancer that you want to modify.
- Click Edit.
- Click Frontend configuration.
- Expand Advanced features. For HTTP keepalive timeout, enter a timeout value.
- Click Update.
- To review your changes, click Review and finalize, and then click Update.
gcloud
For an HTTP load balancer, update the target HTTP proxy by using the
gcloud compute target-http-proxies update
command:
gcloud compute target-http-proxies update TARGET_HTTP_PROXY_NAME \ --http-keep-alive-timeout-sec=HTTP_KEEP_ALIVE_TIMEOUT_SEC \ --global
For an HTTPS load balancer, update the target HTTPS proxy by using the
gcloud compute target-https-proxies update
command:
gcloud compute target-https-proxies update TARGET_HTTPS_PROXY_NAME \ --http-keep-alive-timeout-sec=HTTP_KEEP_ALIVE_TIMEOUT_SEC \ --global
Replace the following:
TARGET_HTTP_PROXY_NAME
: the name of the target HTTP proxy.TARGET_HTTPS_PROXY_NAME
: the name of the target HTTPS proxy.HTTP_KEEP_ALIVE_TIMEOUT_SEC
: the HTTP keepalive timeout value from 5 to 600 seconds.
Limitations
- Backend buckets are only supported with global external Application Load Balancers and classic Application Load Balancer. They aren't supported by the regional external Application Load Balancer or any other load balancer type.
- Backend buckets aren't supported with Identity-Aware Proxy.
- The global external Application Load Balancer doesn't support uploads to Cloud Storage buckets.