Detach the command to open the url so the http server can start

provider/provider.go

@@ -203,7 +203,7 @@ func (p ProviderConfig) Authenticate(t *OAuth2Token) error {
 	})
 
 	// Filter the commands, and replace "{}" with our callback url
-	c := p.AgentCommand[:0]
+	c := make([]string, 0, len(p.AgentCommand))
 	replacedURL := false
 	for _, arg := range p.AgentCommand {
 		if arg == "{}" {
@@ -219,7 +219,8 @@ func (p ProviderConfig) Authenticate(t *OAuth2Token) error {
 
 	//TODO Drop privileges
 	cmd := exec.Command(c[0], c[1:]...)
-	cmd.Run()
+	cmd.Start()
+	cmd.Process.Release()
 
 	server := &http.Server{}
 	go func() {