Initial k8s support in libplayground (#216)

* Initial k8s support in libplayground

* Make tasks never give up + custom event for k8s cluster status

k8s/factory.go

@@ -0,0 +1,140 @@
+package k8s
+
+import (
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/docker/go-connections/tlsconfig"
+	"github.com/play-with-docker/play-with-docker/pwd/types"
+	"github.com/play-with-docker/play-with-docker/router"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/kubernetes/scheme"
+	"k8s.io/client-go/rest"
+)
+
+type FactoryApi interface {
+	GetForInstance(instance *types.Instance) (*kubernetes.Clientset, error)
+	GetKubeletForInstance(instance *types.Instance) (*kubeletClient, error)
+}
+
+func NewClient(instance *types.Instance, proxyHost string) (*kubernetes.Clientset, error) {
+	var durl string
+
+	host := router.EncodeHost(instance.SessionId, instance.RoutableIP, router.HostOpts{EncodedPort: 6443})
+
+	var tlsConfig *tls.Config
+	tlsConfig = tlsconfig.ClientDefault()
+	tlsConfig.InsecureSkipVerify = true
+	tlsConfig.ServerName = host
+
+	var transport http.RoundTripper
+	transport = &http.Transport{
+		DialContext: (&net.Dialer{
+			Timeout:   1 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}).DialContext,
+		TLSClientConfig:     tlsConfig,
+		MaxIdleConnsPerHost: 5,
+	}
+
+	durl = fmt.Sprintf("https://%s", proxyHost)
+
+	cc := rest.ContentConfig{
+		ContentType:          "application/json",
+		GroupVersion:         &schema.GroupVersion{Version: "v1"},
+		NegotiatedSerializer: serializer.DirectCodecFactory{CodecFactory: scheme.Codecs},
+	}
+	restConfig := &rest.Config{
+		Host:          durl,
+		APIPath:       "/api/",
+		BearerToken:   "31ada4fd-adec-460c-809a-9e56ceb75269",
+		ContentConfig: cc,
+	}
+
+	transport, err := rest.HTTPWrappersForConfig(restConfig, transport)
+	if err != nil {
+		return nil, fmt.Errorf("Error wrapping transport %v", err)
+	}
+	cli := &http.Client{
+		Transport: transport,
+	}
+
+	rc, err := rest.RESTClientFor(restConfig)
+	rc.Client = cli
+	if err != nil {
+		return nil, fmt.Errorf("Error creating K8s client %v", err)
+	}
+
+	return kubernetes.New(rc), nil
+}
+
+func NewKubeletClient(instance *types.Instance, proxyHost string) (*kubeletClient, error) {
+	var durl string
+
+	host := router.EncodeHost(instance.SessionId, instance.RoutableIP, router.HostOpts{EncodedPort: 10255})
+
+	transport := &http.Transport{
+		DialContext: (&net.Dialer{
+			Timeout:   1 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}).DialContext,
+		MaxIdleConnsPerHost: 5,
+	}
+
+	durl = fmt.Sprintf("http://%s", host)
+	transport.Proxy = http.ProxyURL(&url.URL{Host: proxyHost})
+
+	cli := &http.Client{
+		Transport: transport,
+	}
+	kc := &kubeletClient{client: cli, baseURL: durl}
+	return kc, nil
+}
+
+type kubeletClient struct {
+	client  *http.Client
+	baseURL string
+}
+
+func (c *kubeletClient) Get(path string) (*http.Response, error) {
+	return c.client.Get(c.baseURL + path)
+}
+
+type metadata struct {
+	Labels map[string]string
+}
+
+type item struct {
+	Metadata metadata
+}
+
+type kubeletPodsResponse struct {
+	Items []item
+}
+
+func (c *kubeletClient) IsManager() (bool, error) {
+	res, err := c.client.Get(c.baseURL + "/pods")
+	if err != nil {
+		return false, err
+	}
+	podsData := &kubeletPodsResponse{}
+
+	json.NewDecoder(res.Body).Decode(podsData)
+
+	for _, i := range podsData.Items {
+		for _, v := range i.Metadata.Labels {
+			if v == "kube-apiserver" {
+				return true, nil
+			}
+		}
+	}
+
+	return false, nil
+}