Kubernetes 101 for Bangalore Kubernauts .

We keep conducting Kubernetes and Openshift meetups as part of www.meetup.com/kubernetes-openshift-India-Meetup/ .

We see great momentum in this meetup group and lots of enthusiam around this. The last events were well received and lots of requests came in to have a hands on training on Kubernetes and Openshift. If you are still to catch up with these emerging technologies, dont delay, just join us in next event planned on 20-May-2017.

More details about this event can be found @ www.meetup.com/kubernetes-openshift-India-Meetup/events/239381714/

This will be a beginner oriented workshop. As a pre requisite, you need to install linux in your laptop, thats it.

We are also looking for volunteers to help and venue to conduct this event.

Please RSVP and let us know if you would like to help us on organizing this event.

ISCSI multipath support in Kubernetes (v1.6) or Openshift.

Multipathing is an important feature in most of the storage setups, so for ISCSI based storage systems.
In most of the ISCSI based storages, multiple paths can be defined as, same IQN shared with more than one portal IPs.
Even if one of the network interface/portal is down, the share/target can be accessed via other active interfaces/portals.
This is indeed a good feature considering I/O from ISCSI initiator to Target.
However the ISCSI plugin in kubernetes was not capable of making use of multipath feature and it
was always just one path configured default in kubernetes. If that path goes down, the target can not be accessed.

Recently I added multipath support to ISCSI kubernetes plugin with this Pull Request.

With this functionality, a kubernetes user/admin can specify the other Target Portal IPs in a new field called portals in ISCSI voulme. Thats the only change required from admin side. If there are mulitple portals, admin can mention these additional target portals in portals field as shown below.

The new structure will look like this.

If you are directly using above volume definition in POD spec, your pod spec may look like this.

Once the pod is up and running, you could check and verify below outputs from the Kubernetes Host where the pod is running:

ISCSI session looks like below:

The device paths:

I believe, this is a nice feature added to Kubernetes ISCSI storage. Please let me know your comments/feedback/suggestions on this.

Support for “Volume Types” option in Kubernetes GlusterFS dynamic provisioner.

Till now, there was no option to specify various volume types and specifications of the dynamically provisioned volumes in GlusterFS provisioner in Kubernetes or Openshift. This functionality has been added some time back to Kubernetes upstream and now a kubernetes/Openshift admin can choose the volume and its specification like volume types in Storage Class parameter.

This has been added in below format to the gluster plugins’ storage class.

Based on above mention, the volumes will be created in the trusted storage pool .

Please let me know if you have any comments/suggestions/feedback about this functionality or if you would like to see any other enhancements to Gluster Dynamic Provisioner in Kubernetes/Openshift.

GlusterFS Containers with Docker, Kubernetes and Openshift

Thought of sharing consolidated news on GlusterFS containers efforts here. Below is the snip of the email which I sent few days back to gluster-users and gluster-devel mailing list. Hope it gives a summary, if not please let me know.

I would like to provide you a status update on the developments with GlusterFS containers and its presence in projects like docker, kubernetes and Openshift.

We have containerized GlusterFS with base image of CentOS and Fedora and its available at Docker Hub[1] to consume.

The Dockerfile of the Image can be found at github[2].

You can pull the image with

# docker pull gluster/gluster-centos
# docker pull gluster/gluster-fedora

The exact steps to be followed to run GlusterFS container is mentioned here[3].

We can deploy GlusterFS pods in Kubernetes Environment and an example blog about this setup can be found here [4].

There is GlusterFS volume plugin available in Kubernetes and openshift v3 which provides Persistent Volume
to the containers in the Environment, How to use GlusterFS containers for Persistent Volume and Persistent Volume Claim in Openshift has been recorded at [5].


Please let us know if you have any comments/suggestions/feedback.