Kuber.NET

Monitoring solution for container jobs scale

Architecture

Basic Architecture

The proposed solution uses an Azure Function to get the message count from a Service Bus Queue. Is is triggered every n minutes. If there is any message, Function calls Kubernetes API in order to scale it up, creating a job on Kube.

Every job has the following pattern: It continuously peek, process and delete messages from queue. If there is no messages in a definied interval, the process finishes.

Basic Architecture + DevOps Included

The solution above can be extended to embrace a DevOps process. In the following proposed architecture a Jenkins instance is triggered by a git repository. Then it builds the container image and pushes to an Azure Container Registry. Right after, Jenkins calls Kubernetes API and notifies the new container image.

Documentation (/docs):

0. Initial Deployment
1. Kubernetes Setup
2. Certificate Setup
3. SDK Development
4. Function Development
5. Deployment and Jobs

Projects (/src):

Library

This .NET Full library implements:

• Authentication
• Deployments scaling
• Jobs creation

Function

The C# Azure Function with the following code snippets:

• Kube.csx: handles calls to Kuber.NET private assembly
• Queue.csx: handles calls to Service Bus Queue using its SDK
• Settings.csx: stores all settings related to the project
• run.csx: business logic inside container scaling rules

Example\Queue:

• Queue.Checker: Check if there is any item in a Queue and use Kuber.NET to increase the number of containers (.NET Full, Project to be deploy inside an Azure Function)
• Queue.Producer: Inserts items in Service Bus Queue (.NET Full, Simulate other enviroment microservices)
• Queue.Consumer: Reads items in Service Bus Queue (.NET Core, Simulate container inside Kubernetes)

Scripts

Scripts for automation (used in our Jenkins instance).

• buildandpush.sh: Builds the .NET core project, create the docker image and deploys it to Azure Container Registry.
• buildimage_example.sh: Example that uses the script above.
• deployment_template.yaml: Uses a previously built image from Azure Container Registry and creates a Deployment on Kubernetes.
• job_template.yaml: Uses a previously built image from Azure Container Registry and creates a Job on Kubernetes.

References

• Azure Functions
• Azure Container Service
• Azure Container Registry
• Service Bus Queue
• Kubernetes
• Kubernetes Jobs
• Kubernetes API Authentication
• Jenkins integration with ACS and Kubernetes