LOTA : The Lord Of The APIs

"One API to rule them all, One API to find them,
One API to bring them all and in the brightness bind them."

What is this?

A generic Kubernetes Operator that can create external resources using Terraform.

Why this?

There is more and more Kubernetes Operators that allows to manage objects in external APIs. This is something Terraform is good at. So instead of creating a specific Operator for an API to manage, why not use Terraform and benefit from the thousands resources it can manage?

How does it works?

A CRD that allows to declare a LotaProvider object to configure a Terraform Provider. An Operator that watches the LotaProvider resources to create a CRD per resource exposed by the Terraform provider, then watches all resources created using this new CRDs (not working yet) and create the resources in the external APIs using Terraform.

Status

For now this is just an ugly Proof Of Concept. CRD creation works, but I couldn't get the resources created using this CRDs watched by the operator yet.

Example

Define a provider to manage an external PostgreSQL cluster:

apiVersion: lotaprovider.lota-operator.io/v1alpha1
kind: LotaProvider
metadata:
  name: pg-prod
spec:
  name: postgresql # the name of the Terraform Provider to use
  version: 1.3.0   # the version of the Terraform Provider to use
  schema:          # the attributes of the Terraform Provider
    - name: host
      value: postgres
    - name: password
      value: mypassword

How to test

Start the docker composition:

$ docker-compose up -d

This will create a k3s cluster for testing.

Register the CRD with the Kubernetes apiserver:

$ KUBECONFIG=./kubeconfig.yaml kubectl apply -f deploy/crds/lotaprovider.lota-operator.io_lotaproviders_crd.yaml

Run the operator:

$ export OPERATOR_NAME=lota-operator
$ operator-sdk up local --namespace=default --kubeconfig=./kubeconfig.yaml

Create a LotaProvider Custom Resource:

$ KUBECONFIG=./kubeconfig.yaml kubectl apply -f deploy/crds/lotaprovider.lota-operator.io_v1alpha1_lotaprovider_cr.yaml

You should see the operator create new CRD for all resources managed by the Terraform Provider defined by the LotaOperator resource.

Create a Resource:

$ KUBECONFIG=./kubeconfig.yaml kubectl apply -f deploy/crds/postgresql.lota-operator.io_v1alpha1_postgresqldatabase_cr.yaml

This should create a PostgreSQL database using the Terraform provider.