buildlet: set TCP keep-alive timeouts, avoid fd leaks
Change-Id: Ia95dcf2d796846f9f0368a9672d3dc0d1f4c0d6f
Reviewed-on: https://go-review.googlesource.com/3770
Reviewed-by: Andrew Gerrand <adg@golang.org>
diff --git a/buildlet/buildletclient.go b/buildlet/buildletclient.go
index 33792f5..f341224 100644
--- a/buildlet/buildletclient.go
+++ b/buildlet/buildletclient.go
@@ -11,6 +11,7 @@
"fmt"
"io"
"io/ioutil"
+ "net"
"net/http"
"net/url"
"strings"
@@ -27,12 +28,24 @@
password: kp.Password(),
httpClient: &http.Client{
Transport: &http.Transport{
+ Dial: defaultDialer(),
DialTLS: kp.tlsDialer(),
},
},
}
}
+// defaultDialer returns the net/http package's default Dial function.
+// Notably, this sets TCP keep-alive values, so when we kill VMs
+// (whose TCP stacks stop replying, forever), we don't leak file
+// descriptors for otherwise forever-stalled TCP connections.
+func defaultDialer() func(network, addr string) (net.Conn, error) {
+ if fn := http.DefaultTransport.(*http.Transport).Dial; fn != nil {
+ return fn
+ }
+ return net.Dial
+}
+
// A Client interacts with a single buildlet.
type Client struct {
ipPort string
