internal: better error message when outpost API controller couldn't fetch outposts

closes #4642

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

internal/outpost/ak/api.go

@@ -55,7 +55,13 @@ func NewAPIController(akURL url.URL, token string) *APIController {
 	config.Host = akURL.Host
 	config.Scheme = akURL.Scheme
 	config.HTTPClient = &http.Client{
-		Transport: web.NewUserAgentTransport(constants.OutpostUserAgent(), web.NewTracingTransport(rsp.Context(), GetTLSTransport())),
+		Transport: web.NewUserAgentTransport(
+			constants.OutpostUserAgent(),
+			web.NewTracingTransport(
+				rsp.Context(),
+				GetTLSTransport(),
+			),
+		),
 	}
 	config.AddDefaultHeader("Authorization", fmt.Sprintf("Bearer %s", token))
 
@@ -73,6 +79,9 @@ func NewAPIController(akURL url.URL, token string) *APIController {
 		time.Sleep(time.Second * 3)
 		return NewAPIController(akURL, token)
 	}
+	if len(outposts.Results) < 1 {
+		panic("No outposts found with given token, ensure the given token corresponds to an authenitk Outpost")
+	}
 	outpost := outposts.Results[0]
 
 	log.WithField("name", outpost.Name).Debug("Fetched outpost configuration")