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Preparing the Local Development Setup (Mac OS X)

Conceptionally, the Machine Controller Manager is designed to run in a container within a Pod inside a Kubernetes cluster. For development purposes, you can run the Machine Controller Manager as a Go process on your local machine. This process connects to your remote cluster to manage VMs for that cluster. That means that the Machine Controller Manager runs outside a Kubernetes cluster which requires providing a Kubeconfig in your local filesystem and point the Machine Controller Manager to it when running it (see below).

Although the following installation instructions are for Mac OS X, similar alternate commands could be found for any Linux distribution.

Installing Golang environment

Install the latest version of Golang (at least v1.8.3 is required) by using Homebrew:

$ brew install golang

In order to perform linting on the Go source code, install Golint:

$ go get -u golang.org/x/lint/golint

Installing Docker (Optional)

In case you want to build Docker images for the Machine Controller Manager you have to install Docker itself. We recommend using Docker for Mac OS X which can be downloaded from here.

Setup Docker Hub account (Optional)

Create a Docker hub account at Docker Hub if you don’t already have one.

Local development

⚠️ Before you start developing, please ensure to comply with the following requirements:

  1. You have understood the principles of Kubernetes, and its components, what their purpose is and how they interact with each other.
  2. You have understood the architecture of the Machine Controller Manager

The development of the Machine Controller Manager could happen by targetting any cluster. You basically need a Kubernetes cluster running on a set of machines. You just need the Kubeconfig file with the required access permissions attached to it.

Installing the Machine Controller Manager locally

Clone the repository from GitHub.

$ git clone git@github.com:gardener/machine-controller-manager.git
$ cd machine-controller-manager

Prepare the cluster

  • Connect to the remote kubernetes cluster where you plan to deploy the Machine Controller Manager using kubectl. Set the environment variable KUBECONFIG to the path of the yaml file containing your cluster info
  • Now, create the required CRDs on the remote cluster using the following command,
$ kubectl apply -f kubernetes/crds.yaml

Getting started

  • Create a dev directory.
  • Copy the kubeconfig of kubernetes cluster where you wish to deploy the machines into dev/target-kubeconfig.yaml.
  • (optional) Copy the kubeconfig of kubernetes cluster from where you wish to manage the machines into dev/control-kubeconfig.yaml. If you do this, also update the Makefile variable CONTROL_KUBECONFIG to point to dev/control-kubeconfig.yaml and CONTROL_NAMESPACE to the namespace in which your controller watches over.
  • There is a rule dev in the Makefile which will automatically start the Machine Controller Manager with development settings:
$ make start
I1227 11:08:19.963638   55523 controllermanager.go:204] Starting shared informers
I1227 11:08:20.766085   55523 controller.go:247] Starting machine-controller-manager

⚠️ The file dev/target-kubeconfig.yaml points to the cluster whose nodes you want to manage. dev/control-kubeconfig.yaml points to the cluster from where you want to manage the nodes from. However, dev/control-kubeconfig.yaml is optional.

The Machine Controller Manager should now be ready to manage the VMs in your kubernetes cluster.

⚠️ This is assuming that your MCM is built to manage machines for any in-tree supported providers. There is a new way to deploy and manage out of tree (external) support for providers whose development can be found here

Testing Machine Classes

To test the creation/deletion of a single instance for one particular machine class you can use the managevm cli. The corresponding INFRASTRUCTURE-machine-class.yaml and the INFRASTRUCTURE-secret.yaml need to be defined upfront. To build and run it

GO111MODULE=on go build -mod=vendor -o managevm cmd/machine-controller-manager-cli/main.go
# create machine
./managevm --secret PATH_TO/INFRASTRUCTURE-secret.yaml --machineclass PATH_TO/INFRASTRUCTURE-machine-class.yaml --classkind INFRASTRUCTURE --machinename test
# delete machine
./managevm --secret PATH_TO/INFRASTRUCTURE-secret.yaml --machineclass PATH_TO/INFRASTRUCTURE-machine-class.yaml --classkind INFRASTRUCTURE --machinename test --machineid INFRASTRUCTURE:///REGION/INSTANCE_ID

Usage

To start using Machine Controller Manager, follow the links given at usage here.