proxy: add support for ALL_PROXY and NO_PROXY
Fixes golang/go#13456
Change-Id: I0b938f824c47b29ac2026eff83e61c2f227a6cc1
Reviewed-on: https://go-review.googlesource.com/47530
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/proxy/proxy.go b/proxy/proxy.go
index 78a8b7b..553ead7 100644
--- a/proxy/proxy.go
+++ b/proxy/proxy.go
@@ -11,6 +11,7 @@
"net"
"net/url"
"os"
+ "sync"
)
// A Dialer is a means to establish a connection.
@@ -27,7 +28,7 @@
// FromEnvironment returns the dialer specified by the proxy related variables in
// the environment.
func FromEnvironment() Dialer {
- allProxy := os.Getenv("all_proxy")
+ allProxy := allProxyEnv.Get()
if len(allProxy) == 0 {
return Direct
}
@@ -41,7 +42,7 @@
return Direct
}
- noProxy := os.Getenv("no_proxy")
+ noProxy := noProxyEnv.Get()
if len(noProxy) == 0 {
return proxy
}
@@ -92,3 +93,42 @@
return nil, errors.New("proxy: unknown scheme: " + u.Scheme)
}
+
+var (
+ allProxyEnv = &envOnce{
+ names: []string{"ALL_PROXY", "all_proxy"},
+ }
+ noProxyEnv = &envOnce{
+ names: []string{"NO_PROXY", "no_proxy"},
+ }
+)
+
+// envOnce looks up an environment variable (optionally by multiple
+// names) once. It mitigates expensive lookups on some platforms
+// (e.g. Windows).
+// (Borrowed from net/http/transport.go)
+type envOnce struct {
+ names []string
+ once sync.Once
+ val string
+}
+
+func (e *envOnce) Get() string {
+ e.once.Do(e.init)
+ return e.val
+}
+
+func (e *envOnce) init() {
+ for _, n := range e.names {
+ e.val = os.Getenv(n)
+ if e.val != "" {
+ return
+ }
+ }
+}
+
+// reset is used by tests
+func (e *envOnce) reset() {
+ e.once = sync.Once{}
+ e.val = ""
+}
diff --git a/proxy/proxy_test.go b/proxy/proxy_test.go
index c19a5c0..0f31e21 100644
--- a/proxy/proxy_test.go
+++ b/proxy/proxy_test.go
@@ -5,14 +5,73 @@
package proxy
import (
+ "bytes"
+ "fmt"
"io"
"net"
"net/url"
+ "os"
"strconv"
+ "strings"
"sync"
"testing"
)
+type proxyFromEnvTest struct {
+ allProxyEnv string
+ noProxyEnv string
+ wantTypeOf Dialer
+}
+
+func (t proxyFromEnvTest) String() string {
+ var buf bytes.Buffer
+ space := func() {
+ if buf.Len() > 0 {
+ buf.WriteByte(' ')
+ }
+ }
+ if t.allProxyEnv != "" {
+ fmt.Fprintf(&buf, "all_proxy=%q", t.allProxyEnv)
+ }
+ if t.noProxyEnv != "" {
+ space()
+ fmt.Fprintf(&buf, "no_proxy=%q", t.noProxyEnv)
+ }
+ return strings.TrimSpace(buf.String())
+}
+
+func TestFromEnvironment(t *testing.T) {
+ ResetProxyEnv()
+
+ type dummyDialer struct {
+ direct
+ }
+
+ RegisterDialerType("irc", func(_ *url.URL, _ Dialer) (Dialer, error) {
+ return dummyDialer{}, nil
+ })
+
+ proxyFromEnvTests := []proxyFromEnvTest{
+ {allProxyEnv: "127.0.0.1:8080", noProxyEnv: "localhost, 127.0.0.1", wantTypeOf: direct{}},
+ {allProxyEnv: "ftp://example.com:8000", noProxyEnv: "localhost, 127.0.0.1", wantTypeOf: direct{}},
+ {allProxyEnv: "socks5://example.com:8080", noProxyEnv: "localhost, 127.0.0.1", wantTypeOf: &PerHost{}},
+ {allProxyEnv: "irc://example.com:8000", wantTypeOf: dummyDialer{}},
+ {noProxyEnv: "localhost, 127.0.0.1", wantTypeOf: direct{}},
+ {wantTypeOf: direct{}},
+ }
+
+ for _, tt := range proxyFromEnvTests {
+ os.Setenv("ALL_PROXY", tt.allProxyEnv)
+ os.Setenv("NO_PROXY", tt.noProxyEnv)
+ ResetCachedEnvironment()
+
+ d := FromEnvironment()
+ if got, want := fmt.Sprintf("%T", d), fmt.Sprintf("%T", tt.wantTypeOf); got != want {
+ t.Errorf("%v: got type = %T, want %T", tt, d, tt.wantTypeOf)
+ }
+ }
+}
+
func TestFromURL(t *testing.T) {
endSystem, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
@@ -140,3 +199,17 @@
return
}
}
+
+func ResetProxyEnv() {
+ for _, env := range []*envOnce{allProxyEnv, noProxyEnv} {
+ for _, v := range env.names {
+ os.Setenv(v, "")
+ }
+ }
+ ResetCachedEnvironment()
+}
+
+func ResetCachedEnvironment() {
+ allProxyEnv.reset()
+ noProxyEnv.reset()
+}
