Preparing the Local Development Setup (Mac OS X)

• Preparing the Local Development Setup (Mac OS X)
  • Installing Golang environment
  • Installing Docker (Optional)
  • Setup Docker Hub account (Optional)
  • Local development
    • Installing the Machine Controller Manager locally
  • Prepare the cluster
  • Getting started
  • Testing Machine Classes
  • Usage

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 targeting 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

Setup and Restore with Gardener

Setup

In gardener access to static kubeconfig files is no longer supported due to security reasons. One needs to generate short-lived (max TTL = 1 day) admin kube configs for target and control clusters. A convenience script/Makefile target has been provided to do the required initial setup which includes:

• Creating a temporary directory where target and control kubeconfigs will be stored.
• Create a request to generate the short lived admin kubeconfigs. These are downloaded and stored in the temporary folder created above.
• In gardener clusters DWD (Dependency Watchdog) runs as an additional component which can interfere when MCM/CA is scaled down. To prevent that an annotation dependency-watchdog.gardener.cloud/ignore-scaling is added to machine-controller-manager deployment which prevents DWD from scaling up the deployment replicas.
• Scales down machine-controller-manager deployment in the control cluster to 0 replica.
• Creates the required .env file and populates required environment variables which are then used by the Makefile in both machine-controller-manager and in machine-controller-manager-provider-<provider-name> projects.
• Copies the generated and downloaded kubeconfig files for the target and control clusters to machine-controller-manager-provider-<provider-name> project as well.

To do the above you can either invoke make gardener-setup or you can directly invoke the script ./hack/gardener_local_setup.sh. If you invoke the script with -h or --help option then it will give you all CLI options that one can pass.

Restore

Once the testing is over you can invoke a convenience script/Makefile target which does the following:

• Removes all generated admin kubeconfig files from both machine-controller-manager and in machine-controller-manager-provider-<provider-name> projects.
• Removes the .env file that was generated as part of the setup from both machine-controller-manager and in machine-controller-manager-provider-<provider-name> projects.
• Scales up machine-controller-manager deployment in the control cluster back to 1 replica.
• Removes the annotation dependency-watchdog.gardener.cloud/ignore-scaling that was added to prevent DWD to scale up MCM.

To do the above you can either invoke make gardener-restore or you can directly invoke the script ./hack/gardener_local_restore.sh. If you invoke the script with -h or --help option then it will give you all CLI options that one can pass.

Setup and Restore without Gardener

Setup

If you are not running MCM components in a gardener cluster, then it is assumed that there is not going to be any DWD (Dependency Watchdog) component. A convenience script/Makefile target has been provided to the required initial setup which includes:

• Copies the provided control and target kubeconfig files to machine-controller-manager-provider-<provider-name> project.
• Scales down machine-controller-manager deployment in the control cluster to 0 replica.
• Creates the required .env file and populates required environment variables which are then used by the Makefile in both machine-controller-manager and in machine-controller-manager-provider-<provider-name> projects.

To do the above you can either invoke make non-gardener-setup or you can directly invoke the script ./hack/non_gardener_local_setup.sh. If you invoke the script with -h or --help option then it will give you all CLI options that one can pass.

Restore

Once the testing is over you can invoke a convenience script/Makefile target which does the following:

• Removes all provided kubeconfig files from both machine-controller-manager and in machine-controller-manager-provider-<provider-name> projects.
• Removes the .env file that was generated as part of the setup from both machine-controller-manager and in machine-controller-manager-provider-<provider-name> projects.
• Scales up machine-controller-manager deployment in the control cluster back to 1 replica.

To do the above you can either invoke make non-gardener-restore or you can directly invoke the script ./hack/non_gardener_local_restore.sh. If you invoke the script with -h or --help option then it will give you all CLI options that one can pass.

Once the setup is done then you can start the machine-controller-manager as a local process using the following Makefile target:

$ 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 -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.