Merge pull request #1958 from ibuildthecloud/kube

Add hidden kube command

Author: ibuildthecloud

go.mod

@@ -206,6 +206,7 @@ require (
 	github.com/morikuni/aec v1.0.0 // indirect
 	github.com/mpvl/unique v0.0.0-20150818121801-cbe035fff7de // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/mxk/go-flowrate v0.0.0-20140419014527-cca7078d478f // indirect
 	github.com/nightlyone/lockfile v1.0.0 // indirect
 	github.com/oklog/ulid v1.3.1 // indirect
 	github.com/olekukonko/tablewriter v0.0.5 // indirect

go.sum

@@ -683,6 +683,8 @@ github.com/mpvl/unique v0.0.0-20150818121801-cbe035fff7de h1:D5x39vF5KCwKQaw+OC9
 github.com/mpvl/unique v0.0.0-20150818121801-cbe035fff7de/go.mod h1:kJun4WP5gFuHZgRjZUWWuH1DTxCtxbHDOIJsudS8jzY=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
+github.com/mxk/go-flowrate v0.0.0-20140419014527-cca7078d478f h1:y5//uYreIhSUg3J1GEMiLbxo1LJaP8RfCpH6pymGZus=
+github.com/mxk/go-flowrate v0.0.0-20140419014527-cca7078d478f/go.mod h1:ZdcZmHo+o7JKHSa8/e818NopupXU1YMK5fe1lsApnBw=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/nightlyone/lockfile v1.0.0 h1:RHep2cFKK4PonZJDdEl4GmkabuhbsRMgk/k3uAmxBiA=
 github.com/nightlyone/lockfile v1.0.0/go.mod h1:rywoIealpdNse2r832aiD9jRk8ErCatROs6LzC841CI=

pkg/cli/acorn.go

@@ -70,6 +70,7 @@ func New() *cobra.Command {
 		NewVolume(cmdContext),
 		NewWait(cmdContext),
 		NewVersion(cmdContext),
+		NewKubectl(cmdContext),
 	)
 	// This will produce an error if the project flag doesn't exist or a completion function has already
 	// been registered for this flag. Not returning the error since neither of these is likely occur.

pkg/cli/kube.go

@@ -0,0 +1,83 @@
+package cli
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+
+	cli "github.com/acorn-io/runtime/pkg/cli/builder"
+	"github.com/spf13/cobra"
+)
+
+func NewKubectl(c CommandContext) *cobra.Command {
+	cmd := cli.Command(&Kube{client: c.ClientFactory}, cobra.Command{
+		Use:          "kube [flags]",
+		Args:         cobra.MinimumNArgs(1),
+		Hidden:       true,
+		SilenceUsage: true,
+		Short:        "Run command with KUBECONFIG env set to a generated kubeconfig of the current project",
+		Example: `
+acorn -j acorn kube k9s
+`})
+	cmd.Flags().SetInterspersed(false)
+	return cmd
+}
+
+type Kube struct {
+	client ClientFactory
+}
+
+func (s *Kube) Run(cmd *cobra.Command, args []string) error {
+	c, err := s.client.CreateDefault()
+	if err != nil {
+		return err
+	}
+
+	ctx, cancel := context.WithCancel(cmd.Context())
+	defer cancel()
+
+	server, err := c.KubeProxyAddress(ctx)
+	if err != nil {
+		return err
+	}
+
+	f, err := os.CreateTemp("", "acorn-kube")
+	if err != nil {
+		return err
+	}
+	defer func() {
+		_ = os.Remove(f.Name())
+	}()
+
+	_, err = f.Write([]byte(fmt.Sprintf(`
+apiVersion: v1
+clusters:
+- cluster:
+    server: "%s"
+  name: default
+contexts:
+- context:
+    cluster: default
+    user: default
+  name: default
+current-context: default
+kind: Config
+preferences: {}
+users:
+- name: default
+`, server)))
+	if err != nil {
+		return err
+	}
+	if err := f.Close(); err != nil {
+		return err
+	}
+
+	k := exec.Command(args[0], args[1:]...)
+	k.Env = append(os.Environ(), fmt.Sprintf("KUBECONFIG=%s", f.Name()))
+	k.Stdin = os.Stdin
+	k.Stdout = os.Stdout
+	k.Stderr = os.Stderr
+	return k.Run()
+}

pkg/cli/testdata/MockClient.go

@@ -119,6 +119,11 @@ type MockClient struct {
 	EventItem        *apiv1.Event
 }
 
+func (m *MockClient) KubeProxyAddress(ctx context.Context) (string, error) {
+	//TODO implement me
+	panic("implement me")
+}
+
 func (m *MockClient) DevSessionRenew(ctx context.Context, name string, client v1.DevSessionInstanceClient) error {
 	//TODO implement me
 	panic("implement me")

pkg/client/client.go

@@ -3,6 +3,7 @@ package client
 import (
 	"context"
 	"net"
+	"net/http"
 	"os"
 	"strconv"
 
@@ -12,6 +13,7 @@ import (
 	"github.com/acorn-io/runtime/pkg/client/term"
 	"github.com/acorn-io/runtime/pkg/k8schannel"
 	"github.com/acorn-io/runtime/pkg/k8sclient"
+	"github.com/acorn-io/runtime/pkg/proxy"
 	"github.com/acorn-io/runtime/pkg/scheme"
 	"github.com/acorn-io/runtime/pkg/streams"
 	"github.com/acorn-io/runtime/pkg/system"
@@ -267,6 +269,7 @@ type Client interface {
 	GetProject() string
 	GetNamespace() string
 	GetClient() (kclient.WithWatch, error)
+	KubeProxyAddress(ctx context.Context) (string, error)
 }
 
 type CredentialLookup func(ctx context.Context, serverAddress string) (*apiv1.RegistryAuth, bool, error)
@@ -376,6 +379,30 @@ type DefaultClient struct {
 	Dialer     *k8schannel.Dialer
 }
 
+func (c *DefaultClient) KubeProxyAddress(ctx context.Context) (string, error) {
+	handler, err := proxy.Handler(c.RESTConfig)
+	if err != nil {
+		return "", err
+	}
+
+	ln, err := net.Listen("tcp", "127.0.0.1:")
+	if err != nil {
+		return "", err
+	}
+
+	srv := &http.Server{
+		Handler: handler,
+		BaseContext: func(listener net.Listener) context.Context {
+			return ctx
+		},
+	}
+	go func() {
+		_ = srv.Serve(ln)
+		os.Exit(1)
+	}()
+	return "http://" + ln.Addr().String(), nil
+}
+
 func (c *DefaultClient) GetProject() string {
 	return c.Project
 }

pkg/client/deferred.go

@@ -444,3 +444,10 @@ func (d *DeferredClient) GetClient() (client.WithWatch, error) {
 	}
 	return d.Client.GetClient()
 }
+
+func (d *DeferredClient) KubeProxyAddress(ctx context.Context) (string, error) {
+	if err := d.create(); err != nil {
+		return "", err
+	}
+	return d.Client.KubeProxyAddress(ctx)
+}

pkg/client/multi.go

@@ -639,3 +639,11 @@ func (m *MultiClient) GetClient() (kclient.WithWatch, error) {
 	}
 	return c.GetClient()
 }
+
+func (m *MultiClient) KubeProxyAddress(ctx context.Context) (string, error) {
+	c, err := m.Factory.ForProject(context.Background(), m.Factory.DefaultProject())
+	if err != nil {
+		panic(err)
+	}
+	return c.KubeProxyAddress(ctx)
+}

pkg/mocks/mock_client.go

@@ -0,0 +1,92 @@
+package proxy
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+
+	"k8s.io/apimachinery/pkg/util/proxy"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/transport"
+)
+
+var (
+	er = &errorResponder{}
+)
+
+type errorResponder struct {
+}
+
+func (e *errorResponder) Error(w http.ResponseWriter, req *http.Request, err error) {
+	w.WriteHeader(http.StatusInternalServerError)
+	_, _ = w.Write([]byte(err.Error()))
+}
+
+// Mostly copied from "kubectl proxy" code
+func Handler(cfg *rest.Config) (http.Handler, error) {
+	host := cfg.Host
+	if !strings.HasSuffix(host, "/") {
+		host = host + "/"
+	}
+	target, err := url.Parse(host)
+	if err != nil {
+		return nil, err
+	}
+
+	transport, err := rest.TransportFor(cfg)
+	if err != nil {
+		return nil, err
+	}
+	upgradeTransport, err := makeUpgradeTransport(cfg, transport)
+	if err != nil {
+		return nil, err
+	}
+
+	proxy := proxy.NewUpgradeAwareHandler(target, transport, false, false, er)
+	proxy.UpgradeTransport = upgradeTransport
+	proxy.UseRequestLocation = true
+	proxy.UseLocationHost = true
+
+	handler := http.Handler(proxy)
+
+	if len(target.Path) > 1 {
+		handler = prependPath(target.Path[:len(target.Path)-1], handler)
+	}
+
+	return proxyHeaders(handler), nil
+}
+
+func proxyHeaders(handler http.Handler) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+		req.Header.Del("Authorization")
+		if req.Header.Get("X-Forwarded-Proto") == "" && req.TLS != nil {
+			req.Header.Set("X-Forwarded-Proto", "https")
+		}
+		handler.ServeHTTP(rw, req)
+	})
+}
+
+func prependPath(prefix string, h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		if len(req.URL.Path) > 1 {
+			req.URL.Path = prefix + req.URL.Path
+		} else {
+			req.URL.Path = prefix
+		}
+		h.ServeHTTP(w, req)
+	})
+}
+
+func makeUpgradeTransport(config *rest.Config, rt http.RoundTripper) (proxy.UpgradeRequestRoundTripper, error) {
+	transportConfig, err := config.TransportConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	upgrader, err := transport.HTTPWrappersForConfig(transportConfig, proxy.MirrorRequest)
+	if err != nil {
+		return nil, err
+	}
+
+	return proxy.NewUpgradeRequestRoundTripper(rt, upgrader), nil
+}