[mapserver-users] External WMS issue

[John Huotari]

I'm having trouble hitting a WMS referenced from within my .map file.  Instead of the image from the WMS being drawn as a layer in my map, I instead get an error logged of "request failed with curl error code 60 (SSL certificate problem: unable to get local issuer certificate) for https://basemap.nationalmap.gov/arcgis/services/USGSTopo/MapServer/WmsServer?LAYERS=0&REQUEST=GetMap&SERVICE=WMS&...<remainder omitted for brevity>"

The confusing thing to me is that the exact same .map file works just fine to produce a map image containing the referenced layer when I run mapserver -nh at a command prompt.  i.e. mapserv -nh "QUERY_STRING=map=test.map&...<remainder omitted for brevity>" > test.png

I've configured a CURL_CA_BUNDLE environment variable pointing to a curl-ca-bundle.crt file and I think the fact that I can reach that external WMS when running the mapserv command at a command prompt would indicate it's configured correctly.  Any thoughts on what could cause the failure I'm seeing though MapServer running on Windows though IIS as a FastCGI app while succeeding when running the same .map file at a command prompt?  Or any thoughts on what I might try to troubleshoot further?

.map file contents are below

MAP
  NAME "MAP"
  CONFIG "MS_ERRORFILE" "e:/LogFiles/ms_error3.txt"
  CONFIG "PROJ_LIB" "E:/ms/projlib/"
  DEBUG 5
  EXTENT -20037508.342789244 -20037508.342789244 20037508.342789244 20037508.342789244
  SIZE 256 256
  SYMBOLSET "E:\ms\basedata\symbols.txt"
  FONTSET "E:\ms\basedata\fonts.txt"
  IMAGECOLOR 255 255 255
  TRANSPARENT ON
  DEFRESOLUTION 72
  RESOLUTION 72
  UNITS meters
  PROJECTION "init=epsg:3857" END
  WEB
    METADATA
      "wms_enable_request" "*"
    END
  END
  LAYER
    STATUS DEFAULT TYPE RASTER NAME "WMS_DRG"
    DEBUG 5
    CONNECTIONTYPE WMS CONNECTION "https://basemap.nationalmap.gov/arcgis/services/USGSTopo/MapServer/WmsServer?"
    PROJECTION "init=epsg:3857" END
    METADATA
      "wms_srs"  "EPSG:3857"
      "wms_name"  "0"
      "wms_server_version"  "1.1.1"
      "wms_format"  "image/png"
    END
  END
END

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