OpenLayers getting OSM from local server

Question

I have successfully installed OSM tile server on a local server. I verified operation using direct calls

http://server_ip/hot/z/x/y.png

I setup a page with OpenLayers 5.2.0. The layer init :

osm = new ol.layer.Tile({
    source: new ol.source.OSM({
        opaque: false,
        url: 'http://server_ip/hot/{z}/{x}/{y}.png'
        //url: 'http://a.tile.openstreetmap.org/{z}/{x}/{y}.png'
    })
});

When I use the a.tile.openstreetmap.org it works ok, but shows blank tiles on my local server call.

I verified the call to my server using wireshark, http request and reply. The return of HTTP are the required tiles (verified by saving them to disk). But OpenLayers is showing blank.

Does OpenLayers expect other parameters (in layer init code) when not specifically using osm server? (or timeout problem since my server is slower?)

Answer 1

If you are not using the default OSM url if may be better to use ol.source.XYZ instead of ol.source.OSM. ol.source.OSM extents ol.source.XYZ by setting default values if the following are not defined:

attributions
attributionsCollapsible (new in 5.3.0)
crossOrigin
maxZoom
url

The OSM default of crossOrigin anonymous when combined with a different url which isn't CORS enabled may result in tiles not loading.