go.mod: update k8s deps to v0.26.2 (remove "replace" rule)

Replace rules are not inherited by consumers of buildx as a module, and as
such would default to use the v0.26.2 version. Removing the replace rules
also removes various (indirect) dependencies (although brings in some new
packages from k8s itself).

The "azure" and "gcp" authentication packages in k8s.io/go-client are now
no longer functional, so removing those imports.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/k8s.io/client-go/transport/cache.go

@@ -93,13 +93,13 @@ func (c *tlsTransportCache) get(config *Config) (http.RoundTripper, error) {
 		return nil, err
 	}
 	// The options didn't require a custom TLS config
-	if tlsConfig == nil && config.Dial == nil && config.Proxy == nil {
+	if tlsConfig == nil && config.DialHolder == nil && config.Proxy == nil {
 		return http.DefaultTransport, nil
 	}
 
 	var dial func(ctx context.Context, network, address string) (net.Conn, error)
-	if config.Dial != nil {
-		dial = config.Dial
+	if config.DialHolder != nil {
+		dial = config.DialHolder.Dial
 	} else {
 		dial = (&net.Dialer{
 			Timeout:   30 * time.Second,
@@ -109,7 +109,7 @@ func (c *tlsTransportCache) get(config *Config) (http.RoundTripper, error) {
 
 	// If we use are reloading files, we need to handle certificate rotation properly
 	// TODO(jackkleeman): We can also add rotation here when config.HasCertCallback() is true
-	if config.TLS.ReloadTLSFiles {
+	if config.TLS.ReloadTLSFiles && tlsConfig != nil && tlsConfig.GetClientCertificate != nil {
 		dynamicCertDialer := certRotatingDialer(tlsConfig.GetClientCertificate, dial)
 		tlsConfig.GetClientCertificate = dynamicCertDialer.GetClientCertificate
 		dial = dynamicCertDialer.connDialer.DialContext
@@ -149,14 +149,6 @@ func tlsConfigKey(c *Config) (tlsCacheKey, bool, error) {
 		// cannot determine equality for functions
 		return tlsCacheKey{}, false, nil
 	}
-	if c.Dial != nil && c.DialHolder == nil {
-		// cannot determine equality for dial function that doesn't have non-nil DialHolder set as well
-		return tlsCacheKey{}, false, nil
-	}
-	if c.TLS.GetCert != nil && c.TLS.GetCertHolder == nil {
-		// cannot determine equality for getCert function that doesn't have non-nil GetCertHolder set as well
-		return tlsCacheKey{}, false, nil
-	}
 
 	k := tlsCacheKey{
 		insecure:           c.TLS.Insecure,

vendor/k8s.io/client-go/transport/cache_go118.go

@@ -0,0 +1,24 @@
+//go:build go1.18
+
+/*
+Copyright 2022 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 transport
+
+// assert at compile time that tlsCacheKey is comparable in a way that will never panic at runtime.
+var _ = isComparable[tlsCacheKey]
+
+func isComparable[T comparable]() {}

vendor/k8s.io/client-go/transport/config.go

@@ -67,11 +67,8 @@ type Config struct {
 	// instead of setting this value directly.
 	WrapTransport WrapperFunc
 
-	// Dial specifies the dial function for creating unencrypted TCP connections.
-	// If specified, this transport will be non-cacheable unless DialHolder is also set.
-	Dial func(ctx context.Context, network, address string) (net.Conn, error)
-	// DialHolder can be populated to make transport configs cacheable.
-	// If specified, DialHolder.Dial must be equal to Dial.
+	// DialHolder specifies the dial function for creating unencrypted TCP connections.
+	// This struct indirection is used to make transport configs cacheable.
 	DialHolder *DialHolder
 
 	// Proxy is the proxy func to be used for all requests made by this
@@ -121,7 +118,7 @@ func (c *Config) HasCertAuth() bool {
 
 // HasCertCallback returns whether the configuration has certificate callback or not.
 func (c *Config) HasCertCallback() bool {
-	return c.TLS.GetCert != nil
+	return c.TLS.GetCertHolder != nil
 }
 
 // Wrap adds a transport middleware function that will give the caller
@@ -153,10 +150,7 @@ type TLSConfig struct {
 	NextProtos []string
 
 	// Callback that returns a TLS client certificate. CertData, CertFile, KeyData and KeyFile supercede this field.
-	// If specified, this transport is non-cacheable unless CertHolder is populated.
-	GetCert func() (*tls.Certificate, error)
-	// CertHolder can be populated to make transport configs that set GetCert cacheable.
-	// If set, CertHolder.GetCert must be equal to GetCert.
+	// This struct indirection is used to make transport configs cacheable.
 	GetCertHolder *GetCertHolder
 }
 

vendor/k8s.io/client-go/transport/token_source.go

@@ -18,8 +18,8 @@ package transport
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net/http"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -132,7 +132,7 @@ type fileTokenSource struct {
 var _ = oauth2.TokenSource(&fileTokenSource{})
 
 func (ts *fileTokenSource) Token() (*oauth2.Token, error) {
-	tokb, err := ioutil.ReadFile(ts.path)
+	tokb, err := os.ReadFile(ts.path)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read token file %q: %v", ts.path, err)
 	}

vendor/k8s.io/client-go/transport/transport.go

@@ -22,9 +22,8 @@ import (
 	"crypto/x509"
 	"encoding/pem"
 	"fmt"
-	"io/ioutil"
 	"net/http"
-	"reflect"
+	"os"
 	"sync"
 	"time"
 
@@ -62,20 +61,12 @@ func New(config *Config) (http.RoundTripper, error) {
 }
 
 func isValidHolders(config *Config) bool {
-	if config.TLS.GetCertHolder != nil {
-		if config.TLS.GetCertHolder.GetCert == nil ||
-			config.TLS.GetCert == nil ||
-			reflect.ValueOf(config.TLS.GetCertHolder.GetCert).Pointer() != reflect.ValueOf(config.TLS.GetCert).Pointer() {
-			return false
-		}
+	if config.TLS.GetCertHolder != nil && config.TLS.GetCertHolder.GetCert == nil {
+		return false
 	}
 
-	if config.DialHolder != nil {
-		if config.DialHolder.Dial == nil ||
-			config.Dial == nil ||
-			reflect.ValueOf(config.DialHolder.Dial).Pointer() != reflect.ValueOf(config.Dial).Pointer() {
-			return false
-		}
+	if config.DialHolder != nil && config.DialHolder.Dial == nil {
+		return false
 	}
 
 	return true
@@ -141,7 +132,7 @@ func TLSConfigFor(c *Config) (*tls.Config, error) {
 				return dynamicCertLoader()
 			}
 			if c.HasCertCallback() {
-				cert, err := c.TLS.GetCert()
+				cert, err := c.TLS.GetCertHolder.GetCert()
 				if err != nil {
 					return nil, err
 				}
@@ -182,10 +173,7 @@ func loadTLSFiles(c *Config) error {
 	}
 
 	c.TLS.KeyData, err = dataFromSliceOrFile(c.TLS.KeyData, c.TLS.KeyFile)
-	if err != nil {
-		return err
-	}
-	return nil
+	return err
 }
 
 // dataFromSliceOrFile returns data from the slice (if non-empty), or from the file,
@@ -195,7 +183,7 @@ func dataFromSliceOrFile(data []byte, file string) ([]byte, error) {
 		return data, nil
 	}
 	if len(file) > 0 {
-		fileData, err := ioutil.ReadFile(file)
+		fileData, err := os.ReadFile(file)
 		if err != nil {
 			return []byte{}, err
 		}