package httputil import ( "net/http" ) type TransportWrapper struct { Default http.RoundTripper Pre func(*http.Request) error Post func(*http.Response) error } var _ http.RoundTripper = (*TransportWrapper)(nil) func NewTransportWrapper() *TransportWrapper { return &TransportWrapper{ Default: http.DefaultTransport, Pre: func(*http.Request) error { return nil }, Post: func(*http.Response) error { return nil }, } } func (c *TransportWrapper) RoundTrip(req *http.Request) (*http.Response, error) { if err := c.Pre(req); err != nil { return nil, err } r, err := c.Default.RoundTrip(req) if err != nil { return nil, err } if err := c.Post(r); err != nil { return nil, err } return r, nil }