style.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE Map [
<!ENTITY longlat "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
]>
<Map background-color="white" srs="&longlat;">

  <Style name="My Style">
    <Rule>
      <LineSymbolizer>
        <CssParameter name="stroke">rgb(50%,50%,50%)</CssParameter>
        <CssParameter name="stroke-width">0.1</CssParameter>
    </LineSymbolizer>
    <PointSymbolizer>
    </PointSymbolizer>
    </Rule>
  </Style>

  <Layer name="world" srs="&longlat;">
    <StyleName>My Style</StyleName>
    <Datasource>
      <Parameter name="type">ogr</Parameter>
      <Parameter name="string">couchdb:http://localhost:5984/</Parameter>
      <Parameter name="layer">osm</Parameter>
    </Datasource>
  </Layer>

</Map>