Preparing the setup

Conceptionally, the Gardener is designated to run in containers within a Pod inside an Kubernetes cluster. It extends the API via the user-aggregated API server concepts. However, if you want to develop it, you may want to work locally with the Gardener without building a Docker image and deploying it to a cluster each and every time. That means that the Gardener runs outside a Kubernetes cluster which requires providing a Kubeconfig in your local filesystem and point the Gardener to it when starting it (see below).

Further details could be found in

  1. principles of Kubernetes, and its components
  2. Kubernetes Development Guide
  3. architecture of the Garden

This setup is based on minikube, a Kubernetes cluster running on a single node.

Installing Golang environment

Install the Golang v1.11. For Mac OS you could use Homebrew:

$ brew install golang

For other OS, please check Go installation documentation.

Make sure to set your $GOPATH environment variable properly (conventionally, it points to $HOME/go).

For your convenience, you can add the bin directory of the $GOPATH to your $PATH: PATH=$PATH:$GOPATH/bin, but it is not necessarily required.

We use Dep for managing Golang package dependencies. Please install it on Mac OS via

$ brew install dep

On other OS please check the Dep installation documentation and the Dep releases page. After downloading the appropriate release in your $GOPATH/bin folder you need to make it executable via chmod +x <dep-release> and to rename it to dep via mv dep-<release> dep.

Golint

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

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

Ginkgo and Gomega

In order to perform tests on the Go source code, please install Ginkgo and Gomega. Please make yourself familiar with both frameworks and read their introductions after installation:

$ go get -u github.com/onsi/ginkgo/ginkgo
$ go get -u github.com/onsi/gomega

Installing kubectl and helm

As already mentioned in the introduction, the communication with the Gardener happens via the Kubernetes (Garden) cluster it is targeting. To interact with that cluster, you need to install kubectl. Please make sure that the version of kubectl is at least v1.11.x.

On Mac OS run

$ brew install kubernetes-cli

Please check the kubectl installation documentation for other OS.

You may also need to develop Helm charts or interact with Tiller using the Helm CLI:

On Mac OS run

$ brew install kubernetes-helm

On other OS please check the Helm installation documentation.

Installing git

We use git as VCS which you need to install.

On Mac OS run

$ brew install git

On other OS, please check the Git installation documentation.

Installing openvpn

We use OpenVPN to establish network connectivity from the control plane running in the Seed cluster to the Shoot’s worker nodes running in private networks. To harden the security we need to generate another secret to encrypt the network traffic (details). Please install the openvpn binary. On Mac OS run

$ brew install openvpn
$ export PATH=$(brew --prefix openvpn)/sbin:$PATH

On other OS, please check the OpenVPN downloads page.

Installing Minikube

You’ll need to have minikube installed and running.

Installing iproute2

iproute2 provides a collection of utilities for network administration and configuration.

On Mac OS run

$ brew install iproute2mac

[Mac OS X only] Install GNU core utilities

When running on Mac OS X you have to install the GNU core utilities:

$ brew install coreutils gnu-sed

This will create symlinks for the GNU utilities with g prefix in /usr/local/bin, e.g., gsed or gbase64. To allow using them without the g prefix please put /usr/local/opt/coreutils/libexec/gnubin at the beginning of your PATH environment variable, e.g., export PATH=/usr/local/opt/coreutils/libexec/gnubin:$PATH.

[Optional] Installing Docker

In case you want to use the “Docker for Mac Kubernetes” or if you want to build Docker images for the Gardener you have to install Docker itself. On Mac OS X, please use Docker for Mac OS X which can be downloaded here.

On other OS, please check the Docker installation documentation.

[Optional] Installing gcloud SDK

In case you have to create a new release or a new hotfix of the Gardener you have to push the resulting Docker image into a Docker registry. Currently, we are using the Google Container Registry (this could change in the future). Please follow the official installation instructions from Google.

Installing Vagrant

In case you want to run the gardener-local-provider and test the creation of Shoot clusters on your machine you have to install Vagrant.

Please make sure that the executable bsdtar is available on your system.

Installing Virtualbox

In this local setup a virtualizer is needed. Here, Virtualbox is used. However, Vagrant supports other virtualizers as well. Please check the Vagrant documentation for further details.

Test nip.io

nip.io is used as an unmanaged DNS implementation for the local setup. Some ISPs don’t handle nip.io very well. Test NS resolution:

nslookup 192.168.99.201.nip.io
Server:         8.8.8.8
Address:        8.8.8.8#53

Non-authoritative answer:
Name:   192.168.99.201.nip.io
Address: 192.168.99.201

If there is an error, switch your DNS server to 8.8.8.8 / 8.8.4.4 or 1.1.1.1.

Local Gardener setup

This setup is only meant to be used for developing purposes, which means that only the control plane of the Gardener cluster is running on your machine.

Get the sources

Clone the repository from GitHub into your $GOPATH.

$ mkdir -p $GOPATH/src/github.com/gardener
$ cd $GOPATH/src/github.com/gardener
$ git clone git@github.com:gardener/gardener.git
$ cd gardener

Start the Gardener

:warning: 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 Garden, and what the various clusters are used for.

The development of the Gardener could happen by targeting any cluster. You basically need a Garden cluster (e.g., a Minikube cluster) and one Seed cluster per cloud provider and per data center/region. You can configure the Gardener controller manager to watch all namespaces for Shoot manifests or to only watch one single namespace.

The commands below will configure your minikube with the absolute minimum resources to launch Gardener API Server and Gardener Controller Manager on a local machine.

Start minikube

First, start minikube with at least Kubernetes v1.11.x. Default cpu and memory settings of minikube machine are not sufficient to host the control plane of a shoot cluster, thus use at least 4 CPUs and 8192MB memory.

$ minikube start --cpus=4 --memory=8192 --kubernetes-version=v1.11.0
Starting local Kubernetes v1.11.0 cluster...
[...]
Kubectl is now configured to use the cluster.

Prepare the Gardener

$ make dev-setup
namespace "garden" created
namespace "garden-dev" created
deployment "etcd" created
service "etcd" created
service "gardener-apiserver" created
endpoints "gardener-apiserver" created
apiservice "v1beta1.garden.sapcloud.io" created

The Gardener exposes the API servers of Shoot clusters via Kubernetes services of type LoadBalancer. In order to establish stable endpoints (robust against changes of the load balancer address), it creates DNS records pointing to these load balancer addresses. They are used internally and by all cluster components to communicate. You need to have control over a domain (or subdomain) for which these records will be created. Please provide an internal domain secret (see this for an example) which contains credentials with the proper privileges. Further information can be found here.

$ kubectl apply -f example/10-secret-internal-domain-unmanaged.yaml
secret/internal-domain-unmanaged created

Run the Gardener API Server and the Gardener Controller Manager

Next, you need to run the Gardener API Server and the Gardener Controller Manager using rules in the Makefile.

$ make start-api
[restful] 2018/02/01 15:39:43 log.go:33: [restful/swagger] listing is available at https:///swaggerapi
[restful] 2018/02/01 15:39:43 log.go:33: [restful/swagger] https:///swaggerui/ is mapped to folder /swagger-ui/
I0201 15:39:43.750573   84958 serve.go:89] Serving securely on [::]:8443
[...]

In another terminal, launch the Gardener Controller Manager

$ make start
time="2018-02-20T13:24:39+02:00" level=info msg="Starting Gardener controller manager..."
time="2018-02-20T13:24:39+02:00" level=info msg="Feature Gates: "
time="2018-02-20T13:24:39+02:00" level=info msg="Gardener controller manager HTTP server started (serving on 0.0.0.0:2718)"
time="2018-02-20T13:24:39+02:00" level=info msg="Found internal domain secret internal-domain-unmanaged for domain nip.io."
time="2018-02-20T13:24:39+02:00" level=info msg="Successfully bootstrapped the Garden cluster."
time="2018-02-20T13:24:39+02:00" level=info msg="Gardener controller manager (version 0.2.0) initialized."
time="2018-02-20T13:24:39+02:00" level=info msg="Quota controller initialized."
time="2018-02-20T13:24:39+02:00" level=info msg="CloudProfile controller initialized."
time="2018-02-20T13:24:39+02:00" level=info msg="SecretBinding controller initialized."
time="2018-02-20T13:24:39+02:00" level=info msg="Watching all namespaces for Shoot resources..."
time="2018-02-20T13:24:39+02:00" level=info msg="Shoot controller initialized."
time="2018-02-20T13:24:39+02:00" level=info msg="Seed controller initialized."
[...]

:information_source: Your username is inferred from the user you are logged in with on your machine. The version is incremented based on the content of the VERSION file. The version is important for the Gardener in order to identify which Gardener version has last operated a Shoot cluster.

The Gardener should now be ready to operate on Shoot resources. You can use

$ kubectl get shoots
No resources found.

to operate against your local running Gardener API server.

Note: It may take several seconds until the minikube cluster recognizes that the Gardener API server has been started and is available. No resources found is the expected result of our initial development setup.

Configure minikube to act as Gardener and Seed Cluster

The Gardener Local Provider gives you the ability to create Shoot clusters on your local machine without the need to have an account on a Cloud Provider. Please make sure that Vagrant is installed (see section Installing Vagrant)

Make sure that you already run make dev-setup and that the Gardener API server and the Gardener controller manager are running via make start-api and make start as described before.

Next, you need to configure minikube to work as the Gardener and as the Seed cluster in such a way that it uses the local Vagrant installation to create the Shoot clusters.

$ make dev-setup-local
cloudprofile "local" created
secret "dev-local" created
secretbinding "core-local" created
Cluster "gardener-dev" set.
User "gardener-dev" set.
Context "gardener-dev" modified.
Switched to context "gardener-dev".
secret "seed-local-dev" created
seed "local-dev" created

Check Vagrant setup

To be sure that the Vagrant has been successfully installed and configured, test your setup:

$ cd vagrant
$ vagrant up
Bringing machine 'core-01' up with 'virtualbox' provider...
==> core-01: Importing base box 'coreos-stable'...
==> core-01: Configuring Ignition Config Drive
==> core-01: Matching MAC address for NAT networking...
[...]

If successful, delete your machine before continuing:

$ vagrant destroy --force
==> core-01: Forcing shutdown of VM...
==> core-01: Destroying VM and associated drives...

$ cd $GOPATH/src/github.com/gardener/gardener

Start the Gardener Local Provider

The Seed cluster provides the possibility to create Shoot clusters on several cloud provider. The Gardener Provider implements a common interface to all supported cloud providers. Here, the corresponding Gardener Provider for Local is used.

By executing

$ make start-local
2018/02/14 10:53:34 Listening on :3777
2018/02/14 10:53:34 Vagrant directory /Users/foo/go/src/github.com/gardener/gardener/vagrant
2018/02/14 10:53:34 user-data path /Users/foo/git/go/src/github.com/gardener/gardener/dev/user-data

the Gardener Local Provider is started.

At this point three processes should run in an individual terminal, the Gardener API server, the Gardener controller manager and finally the Gardener Local Provider.

Create, access and delete a Shoot Cluster

Now, you can create a Shoot cluster by running

$ kubectl apply -f dev/90-shoot-local.yaml
shoot "local" created

When the Shoot API server is created you can download the kubeconfig for it and access it:

$ kubectl --namespace shoot--dev--local get secret kubecfg -o jsonpath="{.data.kubeconfig}" | base64 --decode > dev/shoot-kubeconfig

# Depending on your Internet speed, it can take some time, before your node reports a READY status.
$ kubectl --kubeconfig dev/shoot-kubeconfig get nodes
NAME                    STATUS    ROLES     AGE       VERSION
192.168.99.201.nip.io   Ready     node      1m        v1.9.1

Note: It is required that your minikube has network connectivity to the nodes created by Vagrant.

For additional debugging on your Vagrant node you can ssh into it

$ cd vagrant
$ vagrant ssh

To delete the Shoot cluster

$ ./hack/delete shoot local garden-dev
shoot "local" deleted
shoot "local" patched

Limitations of local Shoot setup

Currently, there are some limitations in the local Shoot setup which need to be considered. Please keep in mind that this setup is intended to be used by Gardener developers.

  • The cloud provider allows to choose from a various list of different machine types. This flexibility is not available in this setup on a single local machine. However, it is possible to specify the Shoot nodes resources (cpu and memory) used by Vagrant in this configuration file. In the Shoot creation process the Machine Controller Manager plays a central role. Due to the limitation in this setup this component is not used.
  • It is not yet possible to create Shoot clusters consisting of more than one worker node. Cluster auto-scaling therefore is not supported
  • It is not yet possible to create two or more Shoot clusters in parallel
  • The Shoot API Server is exposed via a NodePort. In a cloud setup a LoadBalancer would be used
  • The communication between the Seed and the Shoot Clusters uses VPN tunnel. In this setup tunnels are not needed since all components run on localhost

Additional information

In order to ensure that a specific Seed cluster will be chosen, add the .spec.cloud.seed field (see here for an example Shoot manifest).

Please take a look at the example manifests folder to see which resource objects you need to install into your Garden cluster.

Report an issue

See a typo? Have a picture to recommend? Want to edit some words/phrases/sentences? You can simply submit a ticket to request we make the change. If you are github savvy, submit a pull request. Open Github Issue