Kubernetes Job Management

This project provides an abstraction around kubernetes APIs to allow you to dynamically spawn (templated) jobs and clean up after them when they have run.

The two abstractions of interest are the JobManager and JobManagerFactory. The latter provides a factory for the former and helps convert (kubernetes) configuration into a working application.

The JobManager is responsible for creating (templated) jobs given a job definition name and template arguments. It is recommended that the jobs target a dedicated node instance group so as not to contend with live application resources. It is further recommended that you configure the Cluster Autoscaler on this instance group to ensure you do not run out of capacity (even better would be something like the Escalator, a batch job-oriented autoscaler). This will most closely mirror the behavior of a service like AWS Batch, which automatically adjusts the number of nodes based on workload.

The JobManager is also responsible for cleaning up terminated (completed or failed) jobs after some retention period. This is provided for version compatibility across K8s, and to avoid using a feature that is still in Alpha. For more details, see the TTL Controller.

Example Flask Server

The server is a proof-of-concept impleemtnation intended as a replacement for and extension to AWS Batch. It is a flask application housed completely under examples/flask. You do not need to use the server in order to take advantage of the primitives on which it relies.

The server listens on a route for job creation requests, much in the same way AWS batch might be implemented under the hood.

Kubernetes Resources

The Kubernetes resources under examples/k8s/ provide the configuration needed for deploying a server to Kubernetes. Specifically, it demonstrates how to configure jobs to be run by the manager. It relies on ConfigMap volume mounts in order to load the templates into a consistent location. See the JobManagerFactory for the specific required structure.

There is a corresponding dockerfile at examples/Dockerfile that can be used with the templates. You can build it as follows:

docker build -t flask-app -f examples/Dockerfile .