Merge pull request #97857 from liggitt/exec-auth-reuse-dialer

Track opened connections with a single tracker per authenticator

Kubernetes-commit: e9dba7a627520f89778b367fc0d955776f220638
This commit is contained in:
Kubernetes Publisher
2021-01-11 08:39:54 -08:00
5 changed files with 85 additions and 57 deletions

4
Godeps/Godeps.json generated
View File

@@ -460,11 +460,11 @@
},
{
"ImportPath": "k8s.io/api",
"Rev": "9ab310c4912f"
"Rev": "4e9f5db10201"
},
{
"ImportPath": "k8s.io/apimachinery",
"Rev": "0ca7b349afd2"
"Rev": "6c16abd71758"
},
{
"ImportPath": "k8s.io/gengo",

8
go.mod
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@@ -26,14 +26,14 @@ require (
golang.org/x/net v0.0.0-20201110031124-69a78807bb2b
golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
golang.org/x/time v0.0.0-20200630173020-3af7569d3a1e
k8s.io/api v0.0.0-20210105210245-9ab310c4912f
k8s.io/apimachinery v0.0.0-20210103120354-0ca7b349afd2
k8s.io/api v0.0.0-20210107085826-4e9f5db10201
k8s.io/apimachinery v0.0.0-20210106165743-6c16abd71758
k8s.io/klog/v2 v2.4.0
k8s.io/utils v0.0.0-20201110183641-67b214c5f920
sigs.k8s.io/yaml v1.2.0
)
replace (
k8s.io/api => k8s.io/api v0.0.0-20210105210245-9ab310c4912f
k8s.io/apimachinery => k8s.io/apimachinery v0.0.0-20210103120354-0ca7b349afd2
k8s.io/api => k8s.io/api v0.0.0-20210107085826-4e9f5db10201
k8s.io/apimachinery => k8s.io/apimachinery v0.0.0-20210106165743-6c16abd71758
)

4
go.sum
View File

@@ -427,8 +427,8 @@ honnef.co/go/tools v0.0.0-20190418001031-e561f6794a2a/go.mod h1:rf3lG4BRIbNafJWh
honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
honnef.co/go/tools v0.0.1-2019.2.3/go.mod h1:a3bituU0lyd329TUQxRnasdCoJDkEUEAqEt0JzvZhAg=
honnef.co/go/tools v0.0.1-2020.1.3/go.mod h1:X/FiERA/W4tHapMX5mGpAtMSVEeEUOyHaw9vFzvIQ3k=
k8s.io/api v0.0.0-20210105210245-9ab310c4912f/go.mod h1:ugSMEpFie0GsLA3IjyrjlN2Qh3uydrt9YCmiq35Uwk0=
k8s.io/apimachinery v0.0.0-20210103120354-0ca7b349afd2/go.mod h1:WlLqWAHZGg07AeltaI0MV5uk1Omp8xaN0JGLY6gkRpU=
k8s.io/api v0.0.0-20210107085826-4e9f5db10201/go.mod h1:3Xl3BjPKHhLlv0+0TYKMZ8NNiKsby57AFDZIBy5Rv0o=
k8s.io/apimachinery v0.0.0-20210106165743-6c16abd71758/go.mod h1:WlLqWAHZGg07AeltaI0MV5uk1Omp8xaN0JGLY6gkRpU=
k8s.io/gengo v0.0.0-20200413195148-3a45101e95ac/go.mod h1:ezvh/TsK7cY6rbqRK0oQQ8IAqLxYwwyPxAX1Pzy0ii0=
k8s.io/klog/v2 v2.0.0/go.mod h1:PBfzABfn139FHAV07az/IF9Wp1bkk3vpT2XSJ76fSDE=
k8s.io/klog/v2 v2.4.0 h1:7+X0fUguPyrKEC4WjH8iGDg3laWgMo5tMnRTIGTTxGQ=

View File

@@ -18,7 +18,6 @@ package exec
import (
"bytes"
"context"
"crypto/tls"
"crypto/x509"
"errors"
@@ -52,7 +51,6 @@ import (
)
const execInfoEnv = "KUBERNETES_EXEC_INFO"
const onRotateListWarningLength = 1000
const installHintVerboseHelp = `
It looks like you are trying to use a client-go credential plugin that is not installed.
@@ -177,6 +175,12 @@ func newAuthenticator(c *cache, config *api.ExecConfig, cluster *clientauthentic
return nil, fmt.Errorf("exec plugin: invalid apiVersion %q", config.APIVersion)
}
connTracker := connrotation.NewConnectionTracker()
defaultDialer := connrotation.NewDialerWithTracker(
(&net.Dialer{Timeout: 30 * time.Second, KeepAlive: 30 * time.Second}).DialContext,
connTracker,
)
a := &Authenticator{
cmd: config.Command,
args: config.Args,
@@ -196,6 +200,9 @@ func newAuthenticator(c *cache, config *api.ExecConfig, cluster *clientauthentic
interactive: terminal.IsTerminal(int(os.Stdout.Fd())),
now: time.Now,
environ: os.Environ,
defaultDialer: defaultDialer,
connTracker: connTracker,
}
for _, env := range config.Env {
@@ -229,6 +236,11 @@ type Authenticator struct {
now func() time.Time
environ func() []string
// defaultDialer is used for clients which don't specify a custom dialer
defaultDialer *connrotation.Dialer
// connTracker tracks all connections opened that we need to close when rotating a client certificate
connTracker *connrotation.ConnectionTracker
// Cached results.
//
// The mutex also guards calling the plugin. Since the plugin could be
@@ -236,8 +248,6 @@ type Authenticator struct {
mu sync.Mutex
cachedCreds *credentials
exp time.Time
onRotateList []func()
}
type credentials struct {
@@ -266,20 +276,12 @@ func (a *Authenticator) UpdateTransportConfig(c *transport.Config) error {
}
c.TLS.GetCert = a.cert
var dial func(ctx context.Context, network, addr string) (net.Conn, error)
var d *connrotation.Dialer
if c.Dial != nil {
dial = c.Dial
// if c has a custom dialer, we have to wrap it
d = connrotation.NewDialerWithTracker(c.Dial, a.connTracker)
} else {
dial = (&net.Dialer{Timeout: 30 * time.Second, KeepAlive: 30 * time.Second}).DialContext
}
d := connrotation.NewDialer(dial)
a.mu.Lock()
defer a.mu.Unlock()
a.onRotateList = append(a.onRotateList, d.CloseAll)
onRotateListLength := len(a.onRotateList)
if onRotateListLength > onRotateListWarningLength {
klog.Warningf("constructing many client instances from the same exec auth config can cause performance problems during cert rotation and can exhaust available network connections; %d clients constructed calling %q", onRotateListLength, a.cmd)
d = a.defaultDialer
}
c.Dial = d.DialContext
@@ -458,9 +460,7 @@ func (a *Authenticator) refreshCredsLocked(r *clientauthentication.Response) err
if oldCreds.cert != nil && oldCreds.cert.Leaf != nil {
metrics.ClientCertRotationAge.Observe(time.Now().Sub(oldCreds.cert.Leaf.NotBefore))
}
for _, onRotate := range a.onRotateList {
onRotate()
}
a.connTracker.CloseAll()
}
expiry := time.Time{}

View File

@@ -33,18 +33,40 @@ type DialFunc func(ctx context.Context, network, address string) (net.Conn, erro
// Dialer opens connections through Dial and tracks them.
type Dialer struct {
dial DialFunc
*ConnectionTracker
}
// NewDialer creates a new Dialer instance.
// Equivalent to NewDialerWithTracker(dial, nil).
func NewDialer(dial DialFunc) *Dialer {
return NewDialerWithTracker(dial, nil)
}
// NewDialerWithTracker creates a new Dialer instance.
//
// If dial is not nil, it will be used to create new underlying connections.
// Otherwise net.DialContext is used.
// If tracker is not nil, it will be used to track new underlying connections.
// Otherwise NewConnectionTracker() is used.
func NewDialerWithTracker(dial DialFunc, tracker *ConnectionTracker) *Dialer {
if tracker == nil {
tracker = NewConnectionTracker()
}
return &Dialer{
dial: dial,
ConnectionTracker: tracker,
}
}
// ConnectionTracker keeps track of opened connections
type ConnectionTracker struct {
mu sync.Mutex
conns map[*closableConn]struct{}
}
// NewDialer creates a new Dialer instance.
//
// If dial is not nil, it will be used to create new underlying connections.
// Otherwise net.DialContext is used.
func NewDialer(dial DialFunc) *Dialer {
return &Dialer{
dial: dial,
// NewConnectionTracker returns a connection tracker for use with NewDialerWithTracker
func NewConnectionTracker() *ConnectionTracker {
return &ConnectionTracker{
conns: make(map[*closableConn]struct{}),
}
}
@@ -52,17 +74,40 @@ func NewDialer(dial DialFunc) *Dialer {
// CloseAll forcibly closes all tracked connections.
//
// Note: new connections may get created before CloseAll returns.
func (d *Dialer) CloseAll() {
d.mu.Lock()
conns := d.conns
d.conns = make(map[*closableConn]struct{})
d.mu.Unlock()
func (c *ConnectionTracker) CloseAll() {
c.mu.Lock()
conns := c.conns
c.conns = make(map[*closableConn]struct{})
c.mu.Unlock()
for conn := range conns {
conn.Close()
}
}
// Track adds the connection to the list of tracked connections,
// and returns a wrapped copy of the connection that stops tracking the connection
// when it is closed.
func (c *ConnectionTracker) Track(conn net.Conn) net.Conn {
closable := &closableConn{Conn: conn}
// When the connection is closed, remove it from the map. This will
// be no-op if the connection isn't in the map, e.g. if CloseAll()
// is called.
closable.onClose = func() {
c.mu.Lock()
delete(c.conns, closable)
c.mu.Unlock()
}
// Start tracking the connection
c.mu.Lock()
c.conns[closable] = struct{}{}
c.mu.Unlock()
return closable
}
// Dial creates a new tracked connection.
func (d *Dialer) Dial(network, address string) (net.Conn, error) {
return d.DialContext(context.Background(), network, address)
@@ -74,24 +119,7 @@ func (d *Dialer) DialContext(ctx context.Context, network, address string) (net.
if err != nil {
return nil, err
}
closable := &closableConn{Conn: conn}
// When the connection is closed, remove it from the map. This will
// be no-op if the connection isn't in the map, e.g. if CloseAll()
// is called.
closable.onClose = func() {
d.mu.Lock()
delete(d.conns, closable)
d.mu.Unlock()
}
// Start tracking the connection
d.mu.Lock()
d.conns[closable] = struct{}{}
d.mu.Unlock()
return closable, nil
return d.ConnectionTracker.Track(conn), nil
}
type closableConn struct {