we want to deploy a varnish cache in front of a micro service which is deployed on EKS( aws kubernetes service) cluster. As the ip for an application deployed on EKS is dynamic . what are some good workarounds for the same.
I came across this article: https://knplabs.com/en/blog/how2tip-varnish-dynamic-backend-dns-resolution-in-a-docker-swarm-context
As a Varnish Software employee I would also recommend that you use
vmod_goto, which is a Varnish Enterprise VMOD.Varnish Enterprise on AWS without upfront license cost
You mentioned in the title that you'd rather not purchase a Varnish Enterprise license. An alternative would be to use our official AMIs on AWS. See https://www.varnish-software.com/developers/downloads/#amazon-web-services-aws for more information.
On these images there is still a license cost, but it's charged by the hour, it's cheaper and there are even Developer Edition images to test with.
vmod_gotois already packaged on these images, so it's ready to use without having to perform any manual installation.See https://www.varnish-software.com/developers/tutorials/tags/cloud/ for step-by-step tutorials on Ubuntu or Red Hat for this Varnish Enterprise offering.
Open source alternative
However, if you want to use 100% open source software, the article you posted refers to https://github.com/nigoroll/libvmod-dynamic which is an open source alternative for dynamic backends.
You could compile that VMOD from source and use its capabilities to handle dynamic backends.
The API for this VMOD can be found here: https://github.com/nigoroll/libvmod-dynamic/blob/master/src/vmod_dynamic.vcc