Method parseHostname

coderd/workspaceapps/proxy.go:506–556

parseHostname will return if a given request is attempting to access a workspace app via a subdomain. If it is, the hostname of the request is parsed into an appurl.ApplicationURL and true is returned. If the request is not accessing a workspace app, then the next handler is called and false is retu

(rw http.ResponseWriter, r *http.Request, next http.Handler, host string)

// accessing a workspace app, then the next handler is called and false is
// returned.
func (s *Server) parseHostname(rw http.ResponseWriter, r *http.Request, next http.Handler, host string) (appurl.ApplicationURL, bool) {
	// Check if the hostname matches either of the access URLs. If it does, the
	// user was definitely trying to connect to the dashboard/API or a
	// path-based app.
	if appurl.HostnamesMatch(s.DashboardURL.Hostname(), host) || appurl.HostnamesMatch(s.AccessURL.Hostname(), host) {
		next.ServeHTTP(rw, r)
		return appurl.ApplicationURL{}, false
	}

	// If there are no periods in the hostname, then it can't be a valid
	// application URL.
	if !strings.Contains(host, ".") {
		next.ServeHTTP(rw, r)
		return appurl.ApplicationURL{}, false
	}

	// Split the subdomain so we can parse the application details and verify it
	// matches the configured app hostname later.
	subdomain, ok := appurl.ExecuteHostnamePattern(s.HostnameRegex, host)
	if !ok {
		// Doesn't match the regex, so it's not a valid application URL.
		next.ServeHTTP(rw, r)
		return appurl.ApplicationURL{}, false
	}

	// Check if the request is part of the deprecated logout flow. If so, we
	// just redirect to the main access URL.
	if subdomain == appLogoutHostname {
		http.Redirect(rw, r, s.AccessURL.String(), http.StatusSeeOther)
		return appurl.ApplicationURL{}, false
	}

	// Parse the application URL from the subdomain.
	app, err := appurl.ParseSubdomainAppURL(subdomain)
	if err != nil {
		site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
			Status:      http.StatusBadRequest,
			Title:       "Invalid Application URL",
			Description: fmt.Sprintf("Could not parse subdomain application URL %q: %s", subdomain, err.Error()),
			Actions: []site.Action{
				{
					URL:  s.DashboardURL.String(),
					Text: "Back to site",
				},
			},
		})
		return appurl.ApplicationURL{}, false
	}

	return app, true
}

func (s *Server) proxyWorkspaceApp(rw http.ResponseWriter, r *http.Request, appToken SignedToken, path string, app appurl.ApplicationURL) {
	ctx := r.Context()