kind_provider.go

/*
Copyright 2020 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package bootstrap

import (
	"context"
	"fmt"
	"io/ioutil"
	"os"

	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"

	kindv1 "sigs.k8s.io/kind/pkg/apis/config/v1alpha4"
	kind "sigs.k8s.io/kind/pkg/cluster"
)

// KindClusterOption is a NewKindClusterProvider option
type KindClusterOption interface {
	apply(*kindClusterProvider)
}

type kindClusterOptionAdapter func(*kindClusterProvider)

func (adapter kindClusterOptionAdapter) apply(kindClusterProvider *kindClusterProvider) {
	adapter(kindClusterProvider)
}

// WithDockerSockMount implements a New Option that instruct the kindClusterProvider to mount /var/run/docker.sock into
// the new kind cluster.
func WithDockerSockMount() KindClusterOption {
	return kindClusterOptionAdapter(func(k *kindClusterProvider) {
		k.withDockerSock = true
	})
}

// NewKindClusterProvider returns a ClusterProvider that can create a kind cluster.
func NewKindClusterProvider(name string, options ...KindClusterOption) *kindClusterProvider {
	Expect(name).ToNot(BeEmpty(), "name is required for NewKindClusterProvider")

	clusterProvider := &kindClusterProvider{
		name: name,
	}
	for _, option := range options {
		option.apply(clusterProvider)
	}
	return clusterProvider
}

// kindClusterProvider implements a ClusterProvider that can create a kind cluster.
type kindClusterProvider struct {
	name           string
	withDockerSock bool
	kubeconfigPath string
}

// Create a Kubernetes cluster using kind.
func (k *kindClusterProvider) Create(ctx context.Context) {
	Expect(ctx).NotTo(BeNil(), "ctx is required for Create")

	// Sets the kubeconfig path to a temp file.
	// NB. the ClusterProvider is responsible for the cleanup of this file
	f, err := ioutil.TempFile("", "e2e-kind")
	Expect(err).ToNot(HaveOccurred(), "Failed to create kubeconfig file for the kind cluster %q", k.name)
	k.kubeconfigPath = f.Name()

	// Creates the kind cluster
	k.createKindCluster()
}

// createKindCluster calls the kind library taking care of passing options for:
// - use a dedicated kubeconfig file (test should not alter the user environment)
// - if required, mount /var/run/docker.sock
func (k *kindClusterProvider) createKindCluster() {
	kindCreateOptions := []kind.CreateOption{
		kind.CreateWithKubeconfigPath(k.kubeconfigPath),
	}
	if k.withDockerSock {
		kindCreateOptions = append(kindCreateOptions, kind.CreateWithV1Alpha4Config(withDockerSockConfig()))
	}

	err := kind.NewProvider().Create(k.name, kindCreateOptions...)
	Expect(err).ToNot(HaveOccurred(), "Failed to create the kind cluster %q")
}

// withDockerSockConfig returns a kind config for mounting /var/run/docker.sock into the kind node.
func withDockerSockConfig() *kindv1.Cluster {
	cfg := &kindv1.Cluster{
		TypeMeta: kindv1.TypeMeta{
			APIVersion: "kind.x-k8s.io/v1alpha4",
			Kind:       "Cluster",
		},
	}
	kindv1.SetDefaultsCluster(cfg)
	cfg.Nodes = []kindv1.Node{
		{
			Role: kindv1.ControlPlaneRole,
			ExtraMounts: []kindv1.Mount{
				{
					HostPath:      "/var/run/docker.sock",
					ContainerPath: "/var/run/docker.sock",
				},
			},
		},
	}
	return cfg
}

// GetKubeconfigPath returns the path to the kubeconfig file for the cluster.
func (k *kindClusterProvider) GetKubeconfigPath() string {
	return k.kubeconfigPath
}

// Dispose the kind cluster and its kubeconfig file.
func (k *kindClusterProvider) Dispose(ctx context.Context) {
	Expect(ctx).NotTo(BeNil(), "ctx is required for Dispose")

	if err := kind.NewProvider().Delete(k.name, k.kubeconfigPath); err != nil {
		fmt.Fprintf(GinkgoWriter, "Deleting the kind cluster %q failed. You may need to remove this by hand.\n", k.name)
	}
	if err := os.Remove(k.kubeconfigPath); err != nil {
		fmt.Fprintf(GinkgoWriter, "Deleting the kubeconfig file %q file. You may need to remove this by hand.\n", k.kubeconfigPath)
	}
}