Mola (WIP)

A developer-first application format for running containerized applications in k8s

Why do we need Mola?

Helm is a powerful technology to pack you applications and deploy to Kubernetes. It has a powerful engine that makes your application definition declarative. You create new objects or modified them, and Helm takes care of upgrading your resources or deleting the ones you don't need anymore.

But exposing helm templates to a developer is just overkill for the majority of use cases. Developers just want to define the docker image, ports, command, environment variables, volumes and little more. Mola understands a simple docker-compose like format and uses the Helm templating system to traslate this format into Kubernetes resources. Mola relies on Helm to deploy to Kubernetes, taking advantage of Helm declarative approach.

Also, Helm does not cover the full development cycle, like re-building docker images when needed, query application logs or check metrics. The Mola CLI will also cover these scenarios.

Sample

The next sample is the Mola definition for the well-known Voting App application. As you can see, it is about 25 lines of yaml:

services:
  vote:
    public: true
    image: dockersamples/examplevotingapp_vote:before
    ports:
      - 80

  result:
    public: true
    image: dockersamples/examplevotingapp_result:before
    ports:
      - 80

  worker:
    image: dockersamples/examplevotingapp_worker

  db:
    image: postgres:9.4
    ports:
      - 5432

  redis:
    image: redis:alpine
    ports:
      - 6379

The equivalent Helm chart would have more than 400 lines of yaml! To deploy this mola yaml, execute:

helm install test ./chart -f mola.yaml

To destroy it:

helm uninstall test

To render the Kubernetes manifests:

helm template test ./chart -f mola.yaml

Future work

mola deploy and mola destroy commands to abstract the Helm based implementation.
Add build directives to the Mola yaml format.
mola logs, mola exec and mola metrics.

TheMushrr00m/mola

Mola (WIP)

Why do we need Mola?

Sample

Future work