3 Jan 2015

Fedora 21 - Linux Server comes of age with Cockpit management and built in support for Docker

Fedora 21 final was released in December 2014 and marks a defined stage of evolution for what has previously been termed Red Hat's 'bleeding edge', firming up its offering as a solid and viable contender with a three way split for Desktop, Server and Cloud. Of particular interest within the Server version is a new management WUI called Cockpit, in itself a potential game changer but with the addition of built in Docker support even more so. Let's take a look.

There's no doubting the value of a CLI proficient sysadmin and we're not trying to advocate any substitute, however if you're anything like us with an ever increasing amount (of sysadmin) to keep on top of it can't hurt to mix things up here and there, and hey, if it helps to bring some of the 'point and clickers' over to Linux from Windows then that can't be a bad thing right?
It's also interesting to see where Cockpit sits against the likes of Landscape (from Ubuntu) and although more lightweight, as a free product it does deliver a certain cost advantage.

Cockpit is ready to roll straight out of the gate on web port 9090 using either root or user account details created during installation (although admin functionality is limited at basic user level). The running host is (obviously) present and the pleasing WUI offers a tabbed menu for immediate access into sysadmin at all levels (I must sort that memory load). The WUI is also responsive for hooking into from your iPad (and I suppose iPhone 6 Plus?).

Fig:1 - Host Management
Admin categories are self explanatory and I'm not going to drill into and/or detail them other than to highlight the simplicity of multi-host management. Basically, from the main hosts screen just add the remote host (via IP or hostname) and that's it (although there is currently a bug which won't let you add extra hosts unless using the same current user/pass). Once added it appears in the selection screen.

Fig:2 - Multiple Hosts

For any listed host you can also launch a 'Rescue Terminal' from the drop down (i.e an SSH/Terminal session). This is a nice touch and means you can drop into familiar CLI territory without having to fire up a separate TTY.

Ok, enough sysadmin, you're here to see how Docker fits in right? Well, it fits in great. From the main menu for any host the Containers tab takes you into, err, your containers area, from where (yes, you've guessed it) you can stop/start Docker to manage your containers and images (Fig:3).

Fig:3 - Containers and Images

Search and download of Docker images is a simple process via 'Get New Image' and start/run offers options for image and container run commands, container naming and container resource management (CPU, memory, bind port).

Fig:4 - Run Docker Image

Monitoring and stop/start plus live commit of running containers is nicely facilitated (Fig:5) along with dynamic adjustments for memory limit and CPU priority (Fig:6).

Fig:5 - Container Status

Fig:6 - Change Resource Limits

As I said in the opening section, in itself the Cockpit WUI is a great addition, but with such focus for Docker management, which it delivers so well, I personally think it's a real game changer, not only for Fedora but for Linux server releases in general, for, as we know, Docker is going to rule the (virtual) world. You still need to create Dockerfiles for builds via the CLI but having the structure of Dockers image and container services visibly accessible is great for anyone learning the basics to get a feel for how things hang together.

If you fancy giving '21 a spin all images are available directly from the Fedora site. Cloud-side (at time of writing) Digital Ocean are still only offering Fedora 20 for Droplets but there are already a selection of official EC2 AMIs available for AWS, again directly from the Fedora (Cloud) section.

And (here's the sales pitch) if you would like advice or assistance with any of the systems or concepts mentioned in this blog, or if you have any other cloud or DevOps requirements, please feel free to get in touch. CirroNIX are an Accredited AWS Consulting Partner and we would be more than happy to help you get where you want to be, and beyond.


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