Check in the vendor directory

Travis seems to be having issues pulling deps, so we'll have to check in
the vendor directory and prevent the makefile from trying to regenerate
it normally.

vendor/k8s.io/client-go/plugin/pkg/client/auth/exec/exec.go

@@ -0,0 +1,370 @@
+/*
+Copyright 2018 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 exec
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"os"
+	"os/exec"
+	"reflect"
+	"sync"
+	"time"
+
+	"github.com/golang/glog"
+	"golang.org/x/crypto/ssh/terminal"
+	"k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
+	"k8s.io/client-go/pkg/apis/clientauthentication"
+	"k8s.io/client-go/pkg/apis/clientauthentication/v1alpha1"
+	"k8s.io/client-go/pkg/apis/clientauthentication/v1beta1"
+	"k8s.io/client-go/tools/clientcmd/api"
+	"k8s.io/client-go/transport"
+	"k8s.io/client-go/util/connrotation"
+)
+
+const execInfoEnv = "KUBERNETES_EXEC_INFO"
+
+var scheme = runtime.NewScheme()
+var codecs = serializer.NewCodecFactory(scheme)
+
+func init() {
+	v1.AddToGroupVersion(scheme, schema.GroupVersion{Version: "v1"})
+	v1alpha1.AddToScheme(scheme)
+	v1beta1.AddToScheme(scheme)
+	clientauthentication.AddToScheme(scheme)
+}
+
+var (
+	// Since transports can be constantly re-initialized by programs like kubectl,
+	// keep a cache of initialized authenticators keyed by a hash of their config.
+	globalCache = newCache()
+	// The list of API versions we accept.
+	apiVersions = map[string]schema.GroupVersion{
+		v1alpha1.SchemeGroupVersion.String(): v1alpha1.SchemeGroupVersion,
+		v1beta1.SchemeGroupVersion.String():  v1beta1.SchemeGroupVersion,
+	}
+)
+
+func newCache() *cache {
+	return &cache{m: make(map[string]*Authenticator)}
+}
+
+func cacheKey(c *api.ExecConfig) string {
+	return fmt.Sprintf("%#v", c)
+}
+
+type cache struct {
+	mu sync.Mutex
+	m  map[string]*Authenticator
+}
+
+func (c *cache) get(s string) (*Authenticator, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	a, ok := c.m[s]
+	return a, ok
+}
+
+// put inserts an authenticator into the cache. If an authenticator is already
+// associated with the key, the first one is returned instead.
+func (c *cache) put(s string, a *Authenticator) *Authenticator {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	existing, ok := c.m[s]
+	if ok {
+		return existing
+	}
+	c.m[s] = a
+	return a
+}
+
+// GetAuthenticator returns an exec-based plugin for providing client credentials.
+func GetAuthenticator(config *api.ExecConfig) (*Authenticator, error) {
+	return newAuthenticator(globalCache, config)
+}
+
+func newAuthenticator(c *cache, config *api.ExecConfig) (*Authenticator, error) {
+	key := cacheKey(config)
+	if a, ok := c.get(key); ok {
+		return a, nil
+	}
+
+	gv, ok := apiVersions[config.APIVersion]
+	if !ok {
+		return nil, fmt.Errorf("exec plugin: invalid apiVersion %q", config.APIVersion)
+	}
+
+	a := &Authenticator{
+		cmd:   config.Command,
+		args:  config.Args,
+		group: gv,
+
+		stdin:       os.Stdin,
+		stderr:      os.Stderr,
+		interactive: terminal.IsTerminal(int(os.Stdout.Fd())),
+		now:         time.Now,
+		environ:     os.Environ,
+	}
+
+	for _, env := range config.Env {
+		a.env = append(a.env, env.Name+"="+env.Value)
+	}
+
+	return c.put(key, a), nil
+}
+
+// Authenticator is a client credential provider that rotates credentials by executing a plugin.
+// The plugin input and output are defined by the API group client.authentication.k8s.io.
+type Authenticator struct {
+	// Set by the config
+	cmd   string
+	args  []string
+	group schema.GroupVersion
+	env   []string
+
+	// Stubbable for testing
+	stdin       io.Reader
+	stderr      io.Writer
+	interactive bool
+	now         func() time.Time
+	environ     func() []string
+
+	// Cached results.
+	//
+	// The mutex also guards calling the plugin. Since the plugin could be
+	// interactive we want to make sure it's only called once.
+	mu          sync.Mutex
+	cachedCreds *credentials
+	exp         time.Time
+
+	onRotate func()
+}
+
+type credentials struct {
+	token string
+	cert  *tls.Certificate
+}
+
+// UpdateTransportConfig updates the transport.Config to use credentials
+// returned by the plugin.
+func (a *Authenticator) UpdateTransportConfig(c *transport.Config) error {
+	wt := c.WrapTransport
+	c.WrapTransport = func(rt http.RoundTripper) http.RoundTripper {
+		if wt != nil {
+			rt = wt(rt)
+		}
+		return &roundTripper{a, rt}
+	}
+
+	getCert := c.TLS.GetCert
+	c.TLS.GetCert = func() (*tls.Certificate, error) {
+		// If previous GetCert is present and returns a valid non-nil
+		// certificate, use that. Otherwise use cert from exec plugin.
+		if getCert != nil {
+			cert, err := getCert()
+			if err != nil {
+				return nil, err
+			}
+			if cert != nil {
+				return cert, nil
+			}
+		}
+		return a.cert()
+	}
+
+	var dial func(ctx context.Context, network, addr string) (net.Conn, error)
+	if c.Dial != nil {
+		dial = c.Dial
+	} else {
+		dial = (&net.Dialer{Timeout: 30 * time.Second, KeepAlive: 30 * time.Second}).DialContext
+	}
+	d := connrotation.NewDialer(dial)
+	a.onRotate = d.CloseAll
+	c.Dial = d.DialContext
+
+	return nil
+}
+
+type roundTripper struct {
+	a    *Authenticator
+	base http.RoundTripper
+}
+
+func (r *roundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	// If a user has already set credentials, use that. This makes commands like
+	// "kubectl get --token (token) pods" work.
+	if req.Header.Get("Authorization") != "" {
+		return r.base.RoundTrip(req)
+	}
+
+	creds, err := r.a.getCreds()
+	if err != nil {
+		return nil, fmt.Errorf("getting credentials: %v", err)
+	}
+	if creds.token != "" {
+		req.Header.Set("Authorization", "Bearer "+creds.token)
+	}
+
+	res, err := r.base.RoundTrip(req)
+	if err != nil {
+		return nil, err
+	}
+	if res.StatusCode == http.StatusUnauthorized {
+		resp := &clientauthentication.Response{
+			Header: res.Header,
+			Code:   int32(res.StatusCode),
+		}
+		if err := r.a.maybeRefreshCreds(creds, resp); err != nil {
+			glog.Errorf("refreshing credentials: %v", err)
+		}
+	}
+	return res, nil
+}
+
+func (a *Authenticator) credsExpired() bool {
+	if a.exp.IsZero() {
+		return false
+	}
+	return a.now().After(a.exp)
+}
+
+func (a *Authenticator) cert() (*tls.Certificate, error) {
+	creds, err := a.getCreds()
+	if err != nil {
+		return nil, err
+	}
+	return creds.cert, nil
+}
+
+func (a *Authenticator) getCreds() (*credentials, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	if a.cachedCreds != nil && !a.credsExpired() {
+		return a.cachedCreds, nil
+	}
+
+	if err := a.refreshCredsLocked(nil); err != nil {
+		return nil, err
+	}
+	return a.cachedCreds, nil
+}
+
+// maybeRefreshCreds executes the plugin to force a rotation of the
+// credentials, unless they were rotated already.
+func (a *Authenticator) maybeRefreshCreds(creds *credentials, r *clientauthentication.Response) error {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	// Since we're not making a new pointer to a.cachedCreds in getCreds, no
+	// need to do deep comparison.
+	if creds != a.cachedCreds {
+		// Credentials already rotated.
+		return nil
+	}
+
+	return a.refreshCredsLocked(r)
+}
+
+// refreshCredsLocked executes the plugin and reads the credentials from
+// stdout. It must be called while holding the Authenticator's mutex.
+func (a *Authenticator) refreshCredsLocked(r *clientauthentication.Response) error {
+	cred := &clientauthentication.ExecCredential{
+		Spec: clientauthentication.ExecCredentialSpec{
+			Response:    r,
+			Interactive: a.interactive,
+		},
+	}
+
+	env := append(a.environ(), a.env...)
+	if a.group == v1alpha1.SchemeGroupVersion {
+		// Input spec disabled for beta due to lack of use. Possibly re-enable this later if
+		// someone wants it back.
+		//
+		// See: https://github.com/kubernetes/kubernetes/issues/61796
+		data, err := runtime.Encode(codecs.LegacyCodec(a.group), cred)
+		if err != nil {
+			return fmt.Errorf("encode ExecCredentials: %v", err)
+		}
+		env = append(env, fmt.Sprintf("%s=%s", execInfoEnv, data))
+	}
+
+	stdout := &bytes.Buffer{}
+	cmd := exec.Command(a.cmd, a.args...)
+	cmd.Env = env
+	cmd.Stderr = a.stderr
+	cmd.Stdout = stdout
+	if a.interactive {
+		cmd.Stdin = a.stdin
+	}
+
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("exec: %v", err)
+	}
+
+	_, gvk, err := codecs.UniversalDecoder(a.group).Decode(stdout.Bytes(), nil, cred)
+	if err != nil {
+		return fmt.Errorf("decoding stdout: %v", err)
+	}
+	if gvk.Group != a.group.Group || gvk.Version != a.group.Version {
+		return fmt.Errorf("exec plugin is configured to use API version %s, plugin returned version %s",
+			a.group, schema.GroupVersion{Group: gvk.Group, Version: gvk.Version})
+	}
+
+	if cred.Status == nil {
+		return fmt.Errorf("exec plugin didn't return a status field")
+	}
+	if cred.Status.Token == "" && cred.Status.ClientCertificateData == "" && cred.Status.ClientKeyData == "" {
+		return fmt.Errorf("exec plugin didn't return a token or cert/key pair")
+	}
+	if (cred.Status.ClientCertificateData == "") != (cred.Status.ClientKeyData == "") {
+		return fmt.Errorf("exec plugin returned only certificate or key, not both")
+	}
+
+	if cred.Status.ExpirationTimestamp != nil {
+		a.exp = cred.Status.ExpirationTimestamp.Time
+	} else {
+		a.exp = time.Time{}
+	}
+
+	newCreds := &credentials{
+		token: cred.Status.Token,
+	}
+	if cred.Status.ClientKeyData != "" && cred.Status.ClientCertificateData != "" {
+		cert, err := tls.X509KeyPair([]byte(cred.Status.ClientCertificateData), []byte(cred.Status.ClientKeyData))
+		if err != nil {
+			return fmt.Errorf("failed parsing client key/certificate: %v", err)
+		}
+		newCreds.cert = &cert
+	}
+
+	oldCreds := a.cachedCreds
+	a.cachedCreds = newCreds
+	// Only close all connections when TLS cert rotates. Token rotation doesn't
+	// need the extra noise.
+	if a.onRotate != nil && oldCreds != nil && !reflect.DeepEqual(oldCreds.cert, a.cachedCreds.cert) {
+		a.onRotate()
+	}
+	return nil
+}