We are heading to Christmas time, and the Karaf team wanted to prepare some gifts for you 😉
Of course, we are working hard in the preparation of the new Karaf releases. A bunch of bug fixes and improvements will be available in the coming releases: Karaf 2.4.1, Karaf 3.0.3, and Karaf 4.0.0.M2.
Some sub-project releases are also in preparation, especially Cellar. We completely refactored Cellar internals, to provide a more reliable, predictable, and stable behavior. New sync policies are available, new properties, new commands, and also interesting new features like HTTP session replication, or HTTP load balancing. I will prepare a blog about this very soon.
But, we’re also preparing brand-new features.
I heard some people saying: “why do I need Karaf when I have docker.io ?”.
Honestly, I don’t understand this as the purpose is not the same: actually, Karaf on docker.io is a great value.
First, docker.io concepts are not new. It’s more or less new on Linux, but the same kind of features exists for a long time on other systems:
- zones on Solaris
- jail on FreeBSD
- xen on Linux, in the past
So, nothing revolutionary in docker.io, however it’s a very convenient way to host multiple images/pseudo-system on the same machine.
However, docker.io (like the other systems) is focus on the OS: it doesn’t cover by its own the application container. For that, you have to prepare an images with OS plus the application container. For instance, you want to deploy your war file, you have to bootstrap a docker.io image with OS and tomcat (or Karaf ;)).
Moreover, remember the cool features provided by Karaf: ConfigAdmin and dynamic configuration, hotdeployment, features, etc.
You want to deploy your Camel routes, your ActiveMQ broker, your CXF webservices, your application: just use the docker.io image providing a Karaf instance!
And it’s what the Karaf docker.io feature provides. Actually, it provides two things:
- a set of Karaf docker.io images ready to use, with ubuntu/centos images with ready to use Karaf instances (using different combinations)
- a set of shell commands and Karaf commands to easily bootstrap the images from a Karaf instance. It’s actually a good alternative to the Karaf child instances (which are only local to the machine).
Basically, docker.io doesn’t replace Karaf. However, Karaf on docker.io provides a very flexible infrastructure, allowing you to easily bootstrap Karaf instances. Associated with Cellar, you can bootstrap a Karaf cluster very easily as well.
I will prepare the donation and I will blog about the docker.io feature very soon. Stay tuned !!!
A new feature comes in Karaf 4: the Karaf profiles. The purpose is to apply a ready to use set of configurations and provisioning to a Karaf instance.
Thanks to that you can prepare a complete profile containing your configuration and your application (features) and apply multiple profiles to easily create a ready-to-go Karaf instance.
It’s a great complete to the Karaf docker.io feature: the docker.io feature bootstraps the Karaf image, on which you can apply your profiles, all in a row.
Some profiles description is available here: http://mail-archives.apache.org/mod_mbox/karaf-dev/201412.mbox/%3CCAA66TpodJWHVpOqDz2j1QfkPchhBepK_Mwdx0orz7dEVaw8tPQ%40mail.gmail.com%3E.
I’m working on the storage of profiles on Karaf Cave, the application of profiles on running/existing Karaf instances, support of cluster profiles in Cellar, etc.
Again, I will create a specific blog post about profiles soon. Stay tuned again !! 🙂
As a fully enterprise ready container, Karaf has to provide monitoring and management feature. We already provide a bunch of metrics via JMX (we have multiple MBeans for Karaf, Camel, ActiveMQ, CXF, etc).
However, we should provide:
- storage of metrics and messages to be able to have an activity timeline
- SLA definition of the metrics and messages, raising alerts when some metrics are not in the expected value range or when the messages contain a pattern
- dashboard to configure the SLA, display messages, and graph the metrics
As always in Karaf, it should be very simple to install such kind of feature, with an integration of the supported third parties.
That’s why we started to work on Karaf Decanter, a complete and flexible monitoring solution for Karaf and the applications hosted by Karaf (Camel, ActiveMQ, CXF, etc).
The Decanter proposal and description is available here: http://mail-archives.apache.org/mod_mbox/karaf-dev/201410.mbox/%3C543D3D62.6050608%40nanthrax.net%3E.
The current codebase is also available: https://github.com/jbonofre/karaf-decanter.
I’m preparing the donation (some cleansing/polishing in progress).
Again, I will blog about Karaf Decanter asap. Stay tuned again again !! 🙂
You can see like, as always, the Karaf team is committed and dedicated to provide to you very convenient and flexible features. Lot of those features come from your ideas, discussions, proposals. So, keep on discussing with us, we love our users 😉
We hope you will enjoy those new features. We will document and blog about these Christmas gifts soon.
Enjoy Karaf, and Happy Christmas !