AWS Sample: Varnish layer architecture proof of concept.
The architecture is shown as below. The varnish instances are located in the public subnets behind a public load balancer. The app instances are located in the private subnets behind a private load balancer.
The varnish instance contains 2 daemon: Varnish and Nginx. The reason behind this is because Varnish is not compatible with Amazon Elastic Load Balancer. (See this article for reason Using Varnish Proxy Cache with Amazon Web Service ELB Elastic Load Balancer ).
The private load balancer will be masked with private DNS name to simplify the Nginx configuration. We also collect the log for the Nginx to CloudWatch logs using CloudWatch agent. This will be useful to debug the request.
Instead of storing the long DNS of the load balancer, we can easily use the private DNS name.
location / {
# We use internal domain name to mask the internal load balancer.
proxy_pass http://app.internal.prod;
proxy_set_header Host $http_host;
}
This application requires
- AWS CDK. Tested in version 1.114
To deploy the stack, execute
cdk deploy
To clean up the resource, plus you need to empty the log bucket.
aws s3 rm s3://BUCKET_NAME --recursive
Then execute
cdk destroy