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Kris Beevers
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Kris Beevers on
May 9, 2014

NSONE and Cloudstack: custom filters FTW

Apache Cloudstack is an open source cloud platform that we here at NSONE know well, both from our past lives in the hosting space, and because we have customers today whose businesses are built on Cloudstack. Recently, a DNS service used by most Cloudstack deployments announced it was shutting down. The service provides a special mechanism to translate a formatted hostname to an IP address computed from the hostname, and is used to enable an SSL wildcard cert for console access and other purposes.

This impending shutdown leaves Cloudstack operators in a bind: either they need to run their own custom DNS servers implementing the behavior needed by Cloudstack, or they need to create fully realized DNS records for every single IP in their deployment. (That’s probably a lot of DNS records.) One of our customers, Appcore, an awesome private cloud company specializing in Cloudstack deployments, came to NSONE asking for help — could we make them a custom filter for our Filter Chain implementing the wildcard behavior they need to translate hostnames into IPs?

The short answer is: yes.

The Filter Chain is an awesome way to configure complex traffic routing algorithms, but it’s also designed with the awareness that some of our customers have very application specific requirements. Often, meeting those needs is as easy as dropping a custom filter in place — and that’s exactly what we did for Appcore.

We built a super-simple new filter, “PARSE_IPV4”, to implement the same functionality as the existing service used by Cloudstack. From implementation to validation, QA, and production took a couple days, and all Appcore needed to do was point their Cloudstack deployments at a new wildcard DNS record, configured with the PARSE_IPV4 filter, to work around the shutdown of the existing service. Plus, Appcore’s customers now get to take advantage of NSONE’s super-fast, super-reliable globally distributed DNS platform.

Here’s what Appcore’s David Bierce had to say:

Apache CloudStack uses a Dynamic DNS service provided by for external IP discovery. This service will be discontinued as of June 30, 2014. In order to continue using Apache CloudStack on our domain, we would have had to manually create all possible entries for an IP range as A records in a format XXX-XXX-XXX-XXX.subdomain.domain. NSONE created a custom filter that can be applied to our domain that replies dynamically with an appropriate A record, allowing us to continue using Apache Cloudstack’s IP discovery service entirely within our domain.

We normally build custom filter algorithms for our Enterprise customers, but we’re always happy to talk with any of our customers to see if we can help them achieve the control they need for their application. Think you need a custom filter to pull off a unique behavior? Get in touch.

If you are a Cloudstack operator and we can save you some effort by enabling the PARSE_IPV4 filter for your account, just ask — we’re here to help!