http - Remembering things by writing them down

Setting the HTTP User Agent in Go

September 10, 2019
go
http

Here’s the smallest amount of code I could come up with to set the user agent when making a HTTP request in Go:

type UserAgent string

func (u UserAgent) RoundTrip(r *http.Request) (*http.Response, error) {
    r.Header.Set("User-Agent", string(u))
    return http.DefaultTransport.RoundTrip(r)
}

http.DefaultClient.Transport = UserAgent("my-great-program")

Note that this isn’t really legal, since the RoundTripper is not supposed to modify the request.

Using wrk with proxies

September 30, 2016
http
wrk
benchmarking

Based on this extremely helpful post, a slight extension to make it easier to use wrk with a HTTP proxy. url = '' host = '' init = function(args) url = args[1] -- proxy needs absolute URL -- Capture the hostname from the target URL. _, _, host = string.find(url, 'http://([^/]+)/') end request = function() return wrk.format("GET", url, { Host = host }) end Usage is like this: $ wrk -s proxy.