Function checkSubdomainIsolation

pkg/utils/api.go:202–221

checkSubdomainIsolation detects if GitHub Enterprise Server has subdomain isolation enabled by attempting to ping the raw. /_ping endpoint on the subdomain. The raw subdomain must always exist for subdomain isolation.

(scheme, hostname string)

// checkSubdomainIsolation detects if GitHub Enterprise Server has subdomain isolation enabled
// by attempting to ping the raw.<host>/_ping endpoint on the subdomain. The raw subdomain must always exist for subdomain isolation.
func checkSubdomainIsolation(scheme, hostname string) bool {
	subdomainURL := fmt.Sprintf("%s://raw.%s/_ping", scheme, hostname)

	client := &http.Client{
		Timeout: 5 * time.Second,
		// Don't follow redirects - we just want to check if the endpoint exists
		//nolint:revive // parameters are required by http.Client.CheckRedirect signature
		CheckRedirect: func(req *http.Request, via []*http.Request) error {
			return http.ErrUseLastResponse
		},
	}

	resp, err := client.Get(subdomainURL)
	if err != nil {
		return false
	}
	defer resp.Body.Close()

	return resp.StatusCode == http.StatusOK
}

// Note that this does not handle ports yet, so development environments are out.
func parseAPIHost(s string) (APIHost, error) {