Lat/long converter to X/Y (WebMercator ESPG: http://webmappingtools.com/FlexAWidget/CoordinateMenu/

Draw a polyline in OpenLayers https://gis.stackexchange.com/questions/188783/how-to-draw-a-polyline-in-openlayers3

Bosser w/ OL 5+

https://www.npmjs.com/package/ol