proxy: Use our own http transport with crc's proxy config

At the moment, when a proxy is used, crc starts by setting `NO_PROXY`
with some generic values (localhost), and once it knows which bundle
it's going to be using, it adds the domain(s) used by the bundle to the
`NO_PROXY` environment variable.

Early during startup, it's sending HTTP request to check the latest crc
version available, and it uses `http.DefaultTransport`/`ProxyFromEnvironment`
for that.

This is causing problems further down the road, as `ProxyFromEnvironment`
will only read NO_PROXY/HTTP_PROXY/HTTPS_PROXY once, and will use these
cached values for the lifetime of the process. This means
`ProxyFromEnvironment` will never know about `.testing` which is only
added later.

This causes errors at the very end of the startup process when a proxy
is used:
`Cannot update kubeconfig: Head "https://oauth-openshift.apps-crc.testing": Service not available`
`oauth-openshift.apps-crc.testing` is accessed through the proxy as
`NO_PROXY` is not up to date.

In order to avoid this issue, this commit introduces a crc specific
`ProxyFunc` which will use directly the http_proxy/https_proxy/no_proxy
settings from crc rather than getting these from the environment.

This can still be problematic as `oc` code does not always use the http
transport that we pass to it:
openshift/oc#837
but for now this seems to be working well enough.

cmd/crc/cmd/root.go

@@ -58,6 +58,11 @@ func init() {
 	if err != nil {
 		logging.Fatal(err.Error())
 	}
+
+	if err := setProxyDefaults(); err != nil {
+		logging.Fatal(err.Error())
+	}
+
 	// Initiate segment client
 	if segmentClient, err = segment.NewClient(config, httpTransport()); err != nil {
 		logging.Fatal(err.Error())
@@ -77,9 +82,6 @@ func runPrerun(cmd *cobra.Command) error {
 		logFile = constants.DaemonLogFilePath
 	}
 	logging.InitLogrus(logging.LogLevel, logFile)
-	if err := setProxyDefaults(); err != nil {
-		return err
-	}
 
 	for _, str := range defaultVersion().lines() {
 		logging.Debugf(str)
@@ -211,22 +213,33 @@ func attachMiddleware(names []string, cmd *cobra.Command) {
 	}
 }
 
+func defaultTransport() *http.Transport {
+	transport := http.DefaultTransport.(*http.Transport)
+	proxyConfig, err := network.NewProxyConfig()
+	if err != nil {
+		return transport
+	}
+
+	transport = transport.Clone()
+	transport.Proxy = proxyConfig.ProxyFunc()
+	return transport
+}
+
 func httpTransport() http.RoundTripper {
 	if config.Get(crcConfig.ProxyCAFile).IsDefault {
-		return http.DefaultTransport
+		return defaultTransport()
 	}
 	caCert, err := ioutil.ReadFile(config.Get(crcConfig.ProxyCAFile).AsString())
 	if err != nil {
 		logging.Errorf("Cannot read proxy-ca-file, using default http transport: %v", err)
-		return http.DefaultTransport
+		return defaultTransport()
 	}
 	caCertPool := x509.NewCertPool()
 	caCertPool.AppendCertsFromPEM(caCert)
-	return &http.Transport{
-		Proxy: http.ProxyFromEnvironment,
-		TLSClientConfig: &tls.Config{
-			MinVersion: tls.VersionTLS12,
-			RootCAs:    caCertPool,
-		},
+	transport := defaultTransport()
+	transport.TLSClientConfig = &tls.Config{
+		MinVersion: tls.VersionTLS12,
+		RootCAs:    caCertPool,
 	}
+	return transport
 }

pkg/crc/machine/kubeconfig.go

@@ -133,7 +133,8 @@ func addContext(cfg *api.Config, ip string, clusterConfig *types.ClusterConfig,
 		return fmt.Errorf("failed to parse root certificate")
 	}
 	token, err := tokencmd.RequestToken(&restclient.Config{
-		Host: clusterConfig.ClusterAPI,
+		Proxy: clusterConfig.ProxyConfig.ProxyFunc(),
+		Host:  clusterConfig.ClusterAPI,
 		Transport: &http.Transport{
 			TLSClientConfig: &tls.Config{
 				RootCAs:    roots,

pkg/crc/network/proxy.go

@@ -2,6 +2,8 @@ package network
 
 import (
 	"fmt"
+	"net/http"
+	"net/url"
 	"os"
 	"strings"
 
@@ -119,6 +121,22 @@ func (p *ProxyConfig) ApplyToEnvironment() {
 	}
 }
 
+// This wraps https://pkg.go.dev/golang.org/x/net/http/httpproxy#Config.ProxyFunc
+// This can be called on a nil *ProxyConfig
+func (p *ProxyConfig) ProxyFunc() func(req *http.Request) (*url.URL, error) {
+	var cfg httpproxy.Config
+
+	if p != nil {
+		cfg = httpproxy.Config{
+			HTTPProxy:  p.HTTPProxy,
+			HTTPSProxy: p.HTTPSProxy,
+			NoProxy:    p.GetNoProxyString(),
+		}
+	}
+
+	return func(req *http.Request) (*url.URL, error) { return cfg.ProxyFunc()(req.URL) }
+}
+
 // Enabled returns true if at least one proxy (HTTP or HTTPS) is configured. Returns false otherwise.
 func (p *ProxyConfig) IsEnabled() bool {
 	return p.HTTPProxy != "" || p.HTTPSProxy != ""