Creating your Applcation to a Applcation Service using Gfac

Design your applcation

Decide on your applcation and which host to run it. Register the applcation host using gfac portlets. Read corresponding section in userguide for more detail.

You should decide input and output parameters for your applcation service. Gfac will invoke your applcation with input parameters of the Applcation service and will dected the output parameters of your Application service by from stdout of the applcation execuation. Gfac does not support optional patameters and therefore it is not good idea to try make options input parameters. Consider you an instance you want to run a md5 checksum as the applcation. Recommnded approch is to wrap your applcation with a shell script to simplify the command run on the commandline. For an example see following shell script that wraps a md5 verification applcation

				md5sum -c $1 > $outputData/results.txt
				echo "md5result=$outputData/results.txt"

If you applcation has options you should hardcode the options in wrappeing shell script or pass them as parameters and convert them to options via your shell scripts. The line echo "md5result=$outputData/results.txt" is how you tell Gfac about outputs of your application. Result of your applcations must be printed as name value pairs to stdout, where name is Output paramter name(s) of your Applcation serivce. If you have more than one parameter, you should add a a echo statement for each and if it is a array type it should be printed as paramname=[val1 val2 val3 ....]

Check list

  1. Decide on application and where it should run. Install the applcation and register applcation host using gfac portlets
  2. Wrap the applcation using a shell script, use simplest form possible
  3. For every output parameter pint the name and result to stdout as name value pairs
    1. Register the Service