proxy: add ProxyFromEnvironmentUsing
Updates golang/go#31813
Change-Id: Ic05fcdb5881c9e01967697542228224611b7a73f
Reviewed-on: https://go-review.googlesource.com/c/net/+/175100
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jacob Blain Christen <dweomer5@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/proxy/direct.go b/proxy/direct.go
index 26b51c3..3d66bde 100644
--- a/proxy/direct.go
+++ b/proxy/direct.go
@@ -11,9 +11,14 @@
type direct struct{}
-// Direct is a direct proxy: one that makes network connections directly.
+// Direct implements Dialer by making network connections directly using net.Dial or net.DialContext.
var Direct = direct{}
+var (
+ _ Dialer = Direct
+ _ ContextDialer = Direct
+)
+
// Dial directly invokes net.Dial with the supplied parameters.
func (direct) Dial(network, addr string) (net.Conn, error) {
return net.Dial(network, addr)
diff --git a/proxy/proxy.go b/proxy/proxy.go
index 37d3cab..9ff4b9a 100644
--- a/proxy/proxy.go
+++ b/proxy/proxy.go
@@ -26,21 +26,30 @@
User, Password string
}
-// FromEnvironment returns the dialer specified by the proxy related variables in
-// the environment.
+// FromEnvironment returns the dialer specified by the proxy-related
+// variables in the environment and makes underlying connections
+// directly.
func FromEnvironment() Dialer {
+ return FromEnvironmentUsing(Direct)
+}
+
+// FromEnvironmentUsing returns the dialer specify by the proxy-related
+// variables in the environment and makes underlying connections
+// using the provided forwarding Dialer (for instance, a *net.Dialer
+// with desired configuration).
+func FromEnvironmentUsing(forward Dialer) Dialer {
allProxy := allProxyEnv.Get()
if len(allProxy) == 0 {
- return Direct
+ return forward
}
proxyURL, err := url.Parse(allProxy)
if err != nil {
- return Direct
+ return forward
}
- proxy, err := FromURL(proxyURL, Direct)
+ proxy, err := FromURL(proxyURL, forward)
if err != nil {
- return Direct
+ return forward
}
noProxy := noProxyEnv.Get()
@@ -48,7 +57,7 @@
return proxy
}
- perHost := NewPerHost(proxy, Direct)
+ perHost := NewPerHost(proxy, forward)
perHost.AddFromString(noProxy)
return perHost
}
diff --git a/proxy/proxy_test.go b/proxy/proxy_test.go
index d260d69..567fc9c 100644
--- a/proxy/proxy_test.go
+++ b/proxy/proxy_test.go
@@ -6,7 +6,10 @@
import (
"bytes"
+ "context"
+ "errors"
"fmt"
+ "net"
"net/url"
"os"
"strings"
@@ -110,6 +113,37 @@
c.Close()
}
+type funcFailDialer func(context.Context) error
+
+func (f funcFailDialer) Dial(net, addr string) (net.Conn, error) {
+ panic("shouldn't see a call to Dial")
+}
+
+func (f funcFailDialer) DialContext(ctx context.Context, net, addr string) (net.Conn, error) {
+ return nil, f(ctx)
+}
+
+// Check that FromEnvironmentUsing uses our dialer.
+func TestFromEnvironmentUsing(t *testing.T) {
+ ResetProxyEnv()
+ errFoo := errors.New("some error to check our dialer was used)")
+ type key string
+ ctx := context.WithValue(context.Background(), key("foo"), "bar")
+ dialer := FromEnvironmentUsing(funcFailDialer(func(ctx context.Context) error {
+ if got := ctx.Value(key("foo")); got != "bar" {
+ t.Errorf("Resolver context = %T %v, want %q", got, got, "bar")
+ }
+ return errFoo
+ }))
+ _, err := dialer.(ContextDialer).DialContext(ctx, "tcp", "foo.tld:123")
+ if err == nil {
+ t.Fatalf("unexpected success")
+ }
+ if !strings.Contains(err.Error(), errFoo.Error()) {
+ t.Errorf("got unexpected error %q; want substr %q", err, errFoo)
+ }
+}
+
func ResetProxyEnv() {
for _, env := range []*envOnce{allProxyEnv, noProxyEnv} {
for _, v := range env.names {
