http: add Transport.ProxySelector
R=mattn.jp, rsc
CC=golang-dev
https://golang.org/cl/4528077
diff --git a/src/pkg/http/proxy_test.go b/src/pkg/http/proxy_test.go
index 308bf44..9b320b3 100644
--- a/src/pkg/http/proxy_test.go
+++ b/src/pkg/http/proxy_test.go
@@ -40,10 +40,8 @@
no_proxy := "foobar.com, .barbaz.net"
os.Setenv("NO_PROXY", no_proxy)
- tr := &Transport{}
-
for _, test := range UseProxyTests {
- if tr.useProxy(test.host+":80") != test.match {
+ if useProxy(test.host+":80") != test.match {
t.Errorf("useProxy(%v) = %v, want %v", test.host, !test.match, test.match)
}
}
diff --git a/src/pkg/http/transport.go b/src/pkg/http/transport.go
index fa912b1..34bfbdd 100644
--- a/src/pkg/http/transport.go
+++ b/src/pkg/http/transport.go
@@ -24,7 +24,7 @@
// each call to Do and uses HTTP proxies as directed by the
// $HTTP_PROXY and $NO_PROXY (or $http_proxy and $no_proxy)
// environment variables.
-var DefaultTransport RoundTripper = &Transport{}
+var DefaultTransport RoundTripper = &Transport{Proxy: ProxyFromEnvironment}
// DefaultMaxIdleConnsPerHost is the default value of Transport's
// MaxIdleConnsPerHost.
@@ -41,7 +41,12 @@
// TODO: tunable on timeout on cached connections
// TODO: optional pipelining
- IgnoreEnvironment bool // don't look at environment variables for proxy configuration
+ // Proxy optionally specifies a function to return a proxy for
+ // a given Request. If the function returns a non-nil error,
+ // the request is aborted with the provided error. If Proxy is
+ // nil or returns a nil *URL, no proxy is used.
+ Proxy func(*Request) (*URL, os.Error)
+
DisableKeepAlives bool
DisableCompression bool
@@ -51,6 +56,39 @@
MaxIdleConnsPerHost int
}
+// ProxyFromEnvironment returns the URL of the proxy to use for a
+// given request, as indicated by the environment variables
+// $HTTP_PROXY and $NO_PROXY (or $http_proxy and $no_proxy).
+// Either URL or an error is returned.
+func ProxyFromEnvironment(req *Request) (*URL, os.Error) {
+ proxy := getenvEitherCase("HTTP_PROXY")
+ if proxy == "" {
+ return nil, nil
+ }
+ if !useProxy(canonicalAddr(req.URL)) {
+ return nil, nil
+ }
+ proxyURL, err := ParseRequestURL(proxy)
+ if err != nil {
+ return nil, os.ErrorString("invalid proxy address")
+ }
+ if proxyURL.Host == "" {
+ proxyURL, err = ParseRequestURL("http://" + proxy)
+ if err != nil {
+ return nil, os.ErrorString("invalid proxy address")
+ }
+ }
+ return proxyURL, nil
+}
+
+// ProxyURL returns a proxy function (for use in a Transport)
+// that always returns the same URL.
+func ProxyURL(url *URL) func(*Request) (*URL, os.Error) {
+ return func(*Request) (*URL, os.Error) {
+ return url, nil
+ }
+}
+
// RoundTrip implements the RoundTripper interface.
func (t *Transport) RoundTrip(req *Request) (resp *Response, err os.Error) {
if req.URL == nil {
@@ -101,21 +139,11 @@
// Private implementation past this point.
//
-func (t *Transport) getenvEitherCase(k string) string {
- if t.IgnoreEnvironment {
- return ""
- }
- if v := t.getenv(strings.ToUpper(k)); v != "" {
+func getenvEitherCase(k string) string {
+ if v := os.Getenv(strings.ToUpper(k)); v != "" {
return v
}
- return t.getenv(strings.ToLower(k))
-}
-
-func (t *Transport) getenv(k string) string {
- if t.IgnoreEnvironment {
- return ""
- }
- return os.Getenv(k)
+ return os.Getenv(strings.ToLower(k))
}
func (t *Transport) connectMethodForRequest(req *Request) (*connectMethod, os.Error) {
@@ -123,20 +151,12 @@
targetScheme: req.URL.Scheme,
targetAddr: canonicalAddr(req.URL),
}
-
- proxy := t.getenvEitherCase("HTTP_PROXY")
- if proxy != "" && t.useProxy(cm.targetAddr) {
- proxyURL, err := ParseRequestURL(proxy)
+ if t.Proxy != nil {
+ var err os.Error
+ cm.proxyURL, err = t.Proxy(req)
if err != nil {
- return nil, os.ErrorString("invalid proxy address")
+ return nil, err
}
- if proxyURL.Host == "" {
- proxyURL, err = ParseRequestURL("http://" + proxy)
- if err != nil {
- return nil, os.ErrorString("invalid proxy address")
- }
- }
- cm.proxyURL = proxyURL
}
return cm, nil
}
@@ -296,7 +316,7 @@
// useProxy returns true if requests to addr should use a proxy,
// according to the NO_PROXY or no_proxy environment variable.
// addr is always a canonicalAddr with a host and port.
-func (t *Transport) useProxy(addr string) bool {
+func useProxy(addr string) bool {
if len(addr) == 0 {
return true
}
@@ -313,7 +333,7 @@
}
}
- no_proxy := t.getenvEitherCase("NO_PROXY")
+ no_proxy := getenvEitherCase("NO_PROXY")
if no_proxy == "*" {
return false
}
diff --git a/src/pkg/http/transport_test.go b/src/pkg/http/transport_test.go
index 1386550..9cd18ff 100644
--- a/src/pkg/http/transport_test.go
+++ b/src/pkg/http/transport_test.go
@@ -478,6 +478,30 @@
}
}
+func TestTransportProxy(t *testing.T) {
+ ch := make(chan string, 1)
+ ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
+ ch <- "real server"
+ }))
+ defer ts.Close()
+ proxy := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
+ ch <- "proxy for " + r.URL.String()
+ }))
+ defer proxy.Close()
+
+ pu, err := ParseURL(proxy.URL)
+ if err != nil {
+ t.Fatal(err)
+ }
+ c := &Client{Transport: &Transport{Proxy: ProxyURL(pu)}}
+ c.Head(ts.URL)
+ got := <-ch
+ want := "proxy for " + ts.URL + "/"
+ if got != want {
+ t.Errorf("want %q, got %q", want, got)
+ }
+}
+
// TestTransportGzipRecursive sends a gzip quine and checks that the
// client gets the same value back. This is more cute than anything,
// but checks that we don't recurse forever, and checks that
