ssh: leverage proxy from environment

Signed-off-by: Jacob Blain Christen <[email protected]>

plumbing/transport/ssh/common.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/kevinburke/ssh_config"
 	"golang.org/x/crypto/ssh"
+	"golang.org/x/net/proxy"
 )
 
 // DefaultClient is the default SSH client.
@@ -115,7 +116,7 @@ func (c *command) connect() error {
 
 	overrideConfig(c.config, config)
 
-	c.client, err = ssh.Dial("tcp", c.getHostWithPort(), config)
+	c.client, err = dial("tcp", c.getHostWithPort(), config)
 	if err != nil {
 		return err
 	}
@@ -130,6 +131,19 @@ func (c *command) connect() error {
 	return nil
 }
 
+func dial(network, addr string, config *ssh.ClientConfig) (*ssh.Client, error) {
+	dialer := proxy.FromEnvironment()
+	conn, err := dialer.Dial(network, addr)
+	if err != nil {
+		return nil, err
+	}
+	c, chans, reqs, err := ssh.NewClientConn(conn, addr, config)
+	if err != nil {
+		return nil, err
+	}
+	return ssh.NewClient(c, chans, reqs), nil
+}
+
 func (c *command) getHostWithPort() string {
 	if addr, found := c.doGetHostWithPortFromSSHConfig(); found {
 		return addr