Function AddAuthTokenHeader

api/http_client.go:154–190

AddAuthTokenHeader adds an authentication token header for the host specified by the request.

(rt http.RoundTripper, cfg config)

// AddAuthTokenHeader adds an authentication token header for the host specified by the request.
func AddAuthTokenHeader(rt http.RoundTripper, cfg config) http.RoundTripper {
	return &funcTripper{roundTrip: func(req *http.Request) (*http.Response, error) {
		// If the header is already set in the request, don't overwrite it.
		if req.Header.Get(authorization) != "" {
			return rt.RoundTrip(req)
		}

		var redirectHostnameChange bool
		if req.Response != nil && req.Response.Request != nil {
			redirectHostnameChange = getHostname(req) != getHostname(req.Response.Request)
		}

		// Only set header if an initial request or redirect request to the same host as the initial request.
		// If the host has changed during a redirect do not add the authentication token header.
		if redirectHostnameChange {
			return rt.RoundTrip(req)
		}

		hostnameInRequest := ghauth.NormalizeHostname(getHostname(req))
		token, _ := cfg.ActiveToken(hostnameInRequest)
		if token == "" {
			// The request may be aimed at a host's api_host, which gh is
			// not logged in to and so has no token of its own. Fall back
			// to the token of the host it stands in for. This only ever
			// adds a token where there would have been none, so hosts we
			// already authenticate keep resolving exactly as before.
			if canonicalHost, ok := cfg.HostForAPIHost(hostnameInRequest); ok {
				token, _ = cfg.ActiveToken(canonicalHost)
			}
		}
		if token != "" {
			req.Header.Set(authorization, fmt.Sprintf("token %s", token))
		}

		return rt.RoundTrip(req)
	}}
}

// ExtractHeader extracts a named header from any response received by this client and,
// if non-blank, saves it to dest.