Hi Devs,
As we have now removed Kubernetes specific cluster monitoring logic in
Autoscaler we could now use standard Cloud Controller service methods for
managing VM instances and containers. This will make sure that Autoscaling
logic will work the same way for any type of a cartridge.
The idea is to move Kubernetes specific logic to a new class called
KubernetesIaas and implement the Iaas interface. Consequently almost all
the features in the PaaS will work the same manner for MockIaas, Jclouds
Iasses and Kubernetes. This will give us an advantage of verifying
functionality with Mock Iaas and running against other Iaases without much
of a problem.
This class can be defined in the Iaas Providers section in the cartridge
definition. The complete work flow of an application that uses Kubernetes
would be as follows:
*Work Flow of an Application using Kubernetes:*
1. Register Kubernetes clusters.
2. Define Kuberntes Iaas Provider in the cartridge, this will indicate
Stratos that the given cartridge needs Kubernetes support.
Cartridge -> Iaas Providers -> Kubernetes Iaas Provider
3. Define Kuberntes clusters in the Network Partitions. All the partitions
in the above network partitions will use the same configuraiton.
Deployment Policy -> Network Partitions -> Kubernetes Cluster
4. Define an application with the above cartrige
Application -> Cartridges
According to the above configuration when Autoscaler asks Cloud Controller
to start an instance it will find the Iaas Provider in the relevant
partition and if it is Kubernetes it will find the Kubernetes Cluster
defined against the partition and use that information to start the
containers. Instance termination process would work the same way.
I have now started implementing this logic, please add your thoughts.
Thanks
--
Imesh Gunaratne
Technical Lead, WSO2
Committer & PMC Member, Apache Stratos
