Import of https://github.com/ciena/voltctl at commit 40d61fbf3f910ed4017cf67c9c79e8e1f82a33a5
Change-Id: I8464c59e60d76cb8612891db3303878975b5416c
diff --git a/vendor/k8s.io/client-go/plugin/pkg/client/auth/exec/exec.go b/vendor/k8s.io/client-go/plugin/pkg/client/auth/exec/exec.go
new file mode 100644
index 0000000..b88902c
--- /dev/null
+++ b/vendor/k8s.io/client-go/plugin/pkg/client/auth/exec/exec.go
@@ -0,0 +1,360 @@
+/*
+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"
+ "errors"
+ "fmt"
+ "io"
+ "net"
+ "net/http"
+ "os"
+ "os/exec"
+ "reflect"
+ "sync"
+ "time"
+
+ "github.com/davecgh/go-spew/spew"
+ "golang.org/x/crypto/ssh/terminal"
+ v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+ "k8s.io/apimachinery/pkg/runtime"
+ "k8s.io/apimachinery/pkg/runtime/schema"
+ "k8s.io/apimachinery/pkg/runtime/serializer"
+ utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+ "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"
+ "k8s.io/klog"
+)
+
+const execInfoEnv = "KUBERNETES_EXEC_INFO"
+
+var scheme = runtime.NewScheme()
+var codecs = serializer.NewCodecFactory(scheme)
+
+func init() {
+ v1.AddToGroupVersion(scheme, schema.GroupVersion{Version: "v1"})
+ utilruntime.Must(v1alpha1.AddToScheme(scheme))
+ utilruntime.Must(v1beta1.AddToScheme(scheme))
+ utilruntime.Must(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)}
+}
+
+var spewConfig = &spew.ConfigState{DisableMethods: true, Indent: " "}
+
+func cacheKey(c *api.ExecConfig) string {
+ return spewConfig.Sprint(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 {
+ c.Wrap(func(rt http.RoundTripper) http.RoundTripper {
+ return &roundTripper{a, rt}
+ })
+
+ if c.TLS.GetCert != nil {
+ return errors.New("can't add TLS certificate callback: transport.Config.TLS.GetCert already set")
+ }
+ c.TLS.GetCert = 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 {
+ klog.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
+}