Cloud CDN integration in GCP - Commands & Configuration

Introduction

Cloud CDN helps deliver your website or app content faster by storing copies closer to users around the world. It solves the problem of slow loading times by caching content at locations near your users.

When you want to speed up your website for visitors in different countries.

When you have a web app that serves large files like images or videos and want to reduce load on your main server.

When you want to reduce bandwidth costs by caching content at Google’s edge locations.

When you want to improve reliability by serving cached content even if your main server is slow or down.

When you want to secure your content delivery with HTTPS and Google’s security features.

Config File - backend_service.yaml

backend_service.yaml

apiVersion: compute.googleapis.com/v1
kind: BackendService
metadata:
  name: example-backend-service
spec:
  backends:
  - group: projects/my-project/zones/us-central1-a/instanceGroups/example-instance-group
  cdnPolicy:
    cacheMode: CACHE_ALL_STATIC
    signedUrlCacheMaxAgeSec: 3600
  protocol: HTTP
  portName: http
  timeoutSec: 30
  enableCdn: true

This file defines a Backend Service in Google Cloud that uses Cloud CDN.

backends: Points to the instance group serving your content.

cdnPolicy: Configures caching behavior, here caching all static content for 1 hour.

enableCdn: Enables Cloud CDN for this backend service.

Commands

Creates a backend service named example-backend-service with HTTP protocol and enables Cloud CDN globally.

Terminal

gcloud compute backend-services create example-backend-service --protocol=HTTP --port-name=http --timeout=30 --enable-cdn --global

Expected Output

Created [https://www.googleapis.com/compute/v1/projects/my-project/global/backendServices/example-backend-service].

→

--enable-cdn - Turns on Cloud CDN for this backend service.

→

--global - Creates the backend service as a global resource.

Adds an instance group named example-instance-group in zone us-central1-a as a backend to the backend service.

Terminal

gcloud compute backend-services add-backend example-backend-service --instance-group=example-instance-group --instance-group-zone=us-central1-a --global

Expected Output

Updated [https://www.googleapis.com/compute/v1/projects/my-project/global/backendServices/example-backend-service].

→

--instance-group - Specifies the instance group to add.

→

--instance-group-zone - Specifies the zone of the instance group.

→

--global - Indicates the backend service is global.

Creates a URL map that routes all traffic to the backend service with Cloud CDN enabled.

Terminal

gcloud compute url-maps create example-url-map --default-service=example-backend-service

Expected Output

Created [https://www.googleapis.com/compute/v1/projects/my-project/global/urlMaps/example-url-map].

Creates an HTTP proxy that uses the URL map to route requests to the backend service.

Terminal

gcloud compute target-http-proxies create example-http-proxy --url-map=example-url-map

Expected Output

Created [https://www.googleapis.com/compute/v1/projects/my-project/global/targetHttpProxies/example-http-proxy].

Creates a global forwarding rule to send incoming HTTP traffic on port 80 to the HTTP proxy.

Terminal

gcloud compute forwarding-rules create example-http-forwarding-rule --global --target-http-proxy=example-http-proxy --ports=80

Expected Output

Creating forwarding rule...done.

NAME                        REGION  IP_ADDRESS  IP_PROTOCOL  PORT_RANGE  TARGET

example-http-forwarding-rule  global  34.123.45.67  TCP          80          https://www.googleapis.com/compute/v1/projects/my-project/global/targetHttpProxies/example-http-proxy

→

--global - Creates a global forwarding rule.

→

--ports - Specifies the port to listen on.

Checks the backend service details to verify Cloud CDN is enabled and caching policy is set.

Terminal

gcloud compute backend-services describe example-backend-service --global

Expected Output

cdnPolicy:

  cacheMode: CACHE_ALL_STATIC

  signedUrlCacheMaxAgeSec: 3600

enableCdn: true

name: example-backend-service

protocol: HTTP

portName: http

timeoutSec: 30

→

--global - Specifies the backend service is global.

Key Concept

If you remember nothing else from this pattern, remember: enabling Cloud CDN on a backend service caches your content at Google’s edge locations to speed up delivery worldwide.

Common Mistakes

Not enabling CDN when creating the backend service.

Without enabling CDN, your content won't be cached and users won't get faster delivery.

Always use the --enable-cdn flag when creating or updating your backend service.

Adding backend instance groups without specifying the correct zone.

The backend service won't connect properly to your instance group, causing traffic failures.

Use the --instance-group-zone flag with the correct zone when adding backends.

Skipping verification of backend service settings after creation.

You might miss misconfigurations like CDN not being enabled or wrong cache policies.

Run gcloud compute backend-services describe to confirm settings.

Summary

Create a backend service with Cloud CDN enabled using gcloud commands.

Add your instance group as a backend to serve your content.

Set up URL maps, HTTP proxies, and forwarding rules to route traffic through Cloud CDN.

Verify your backend service to ensure CDN is active and caching policies are correct.