Your new app is brilliant; the code you've spent six months writing is beautiful. But when you upload it from your laptop to the web server, it just doesn't work. You know why: your laptop's is configured slightly differently than the server, and now you're now going to have to spend hours – maybe days – figuring out what you need to change to make it run properly.

This is one of the biggest headaches for software developers. It's something that a popular piece of open source software called Docker can help alleviate. And now Docker has a helper of its own, an open-source project called Panamax that makes it easier to use Docker on the cloud.

Docker packs applications into software "containers," which contain everything required to run the application. This makes it much easier to move an application from a developer's laptop to a server, or to migrate the app from one server to another. Since its first public release in January 2013, the software has been downloaded over 8.7 million times and attracted over 553 contributors. There are now over 10,000 Docker related projects on the code hosting and collaboration platform GitHub.

But even though Docker makes it easier to run apps in the cloud, setting up the cloud that those applications will actually run on is still a pain. That's because even though it's simple to have two or more Docker containers on the same server talk with each other, enabling communications between containers that are spread across multiple servers is a bit of a nightmare. "You can do it, but it's something of a dark art," says Lucas Carlson, the founder of the cloud computing company AppFog, which was acquired by CenturyLink last year.

The 'Dark Art' Assistant

That's why Carlson's team at CenturyLink built Panamax, a new open source tool designed to make it a snap to build and maintain Docker clouds.

Panamax is based around bundles of Docker containers called "templates," which are pre-configured sets of apps that are ready to communicate with each other. For example, if you wanted to run a WordPress blog on your Docker cloud, you could install a Panamax template that includes both the WordPress application and the required database server. Once a template has been created, it can be instantly deployed with the Panamax interface.

Panamax.

In many ways, Panamax resembles a platform-as-a-service — or PaaS — much like Heroku, Google App Engine, or a growing number of Docker-based systems like Flynn and Deis. But Carlson says Panamax isn't a PaaS. "I already built a PaaS, and I don't want to build another one," he says. Instead, he describes Panamax as a "cloud builder." You could even use it to install a PaaS on your server, if you wanted.

Panamax already has many supporters in the container community, including Docker itself. "I think it's pretty exciting," says Docker vice president of services James Turnbull. "Panamax helps with service composition and it's very 'point and click' which is awesome as a front-end to Docker."

>'It's very 'point and click' which is awesome as a front-end to Docker'

In some ways, Panamax looks like it could compete with Docker, the company. After all, selling premium management and configuration tools is a standard way to build a business around open source cloud technologies. But Docker's vice president of services James Turnbull says the company has different objectives from Panamax.

"Docker is more focused on the end-to-end application life cycle," he says, adding that the company is more focused on helping developers build their apps and transfer them to Docker environments, than in building software that helps system administrators manage those environments. That's what Panamax is for.

Carlson says that although CenturyLink will use Panamax internally to help it setup servers, it won't be selling a premium version anytime soon. The real purpose of the project is to set the stage for things to come. "What we're doing is placing bets on the future of certain technologies," he says. "Panamax is a bet that Docker will revolutionize the cloud."