lib/template.xml
<Map srs="+init=epsg:3857">
<Style name="geoms">
<Rule>
<Filter>[mapnik::geometry_type]=polygon or [fill]</Filter>
<PolygonSymbolizer fill="[fill]" fill-opacity="[fill-opacity]" />
</Rule>
<Rule>
<Filter>[mapnik::geometry_type]=linestring or [stroke]</Filter>
<LineSymbolizer stroke="[stroke]" stroke-width="[stroke-width]" stroke-opacity="[stroke-opacity]" />
</Rule>
</Style>
<Style name="points" filter-mode="first">
<Rule>
<Filter>[mapnik::geometry_type]=point and [marker-path]</Filter>
<PointSymbolizer
file="[marker-path]"
allow-overlap="true"
ignore-placement="true"
/>
</Rule>
</Style>
<Layer name="layer" srs="+init=epsg:4326">
<StyleName>geoms</StyleName>
<StyleName>points</StyleName>
<Datasource>
<Parameter name="type">geojson</Parameter>
<Parameter name="inline"><![CDATA[{{geojson}}]]></Parameter>
</Datasource>
</Layer>
</Map>