Yes, that's pretty much it! Good investigation.

For #3 you will have to make a best effort as to what is to be
contained in the JSON as it might have to be adjusted for TAVERNA-878.


Are you considering also having a minimal go at TAVERNA-878? :)

On 15 March 2016 at 15:17, Thilina Manamgoda <[email protected]> wrote:
> Hi,
>   For TAVERNA-880 (discovery)  these are the things i should do ?
>
> 1). Build service discovery plugin for CWL .
>
>               1. Implement AbstractConfigurableServiceProvider which will
> look for *.cwl files in given directory.
>               2. provide ServiceDescriptions which holds configurations for
> CWL when  findServiceDescriptionsAsync is called.These configurations
> should be in JSON .
>               3.These JSON configuration should have details to build
> CWLActivity.class  like How Input port and output port are defined .
>
> 2) Testing and documentaion
>
>
>
>              Am i correct ?
>
> regards ,
> Thilina.
>
>
> On Tue, Mar 15, 2016 at 8:24 PM, Thilina Manamgoda <[email protected]>
> wrote:
>
>> Hi,
>>
>>
>> On Tue, Mar 15, 2016 at 8:00 PM, Stian Soiland-Reyes <[email protected]>
>> wrote:
>>
>>> On 15 March 2016 at 08:07, Thilina Manamgoda <[email protected]>
>>> wrote:
>>>
>>> > I have gone through the tutorials Service invocation plugin
>>> > <
>>> http://dev.mygrid.org.uk/wiki/display/developer/Tutorial+-+Service+invocation+plugin
>>> >
>>> >  and Service discovery plugin
>>> > <
>>> http://dev.mygrid.org.uk/wiki/display/developer/Tutorial+-+Service+discovery+plugin
>>> >.
>>>
>>> Great!  Did you find any issues while doing so?
>>>
>>>
>>> > So in order to bring CWL workflows to the Taverna i have to implement
>>> Service
>>> > discovery plugin
>>> > <
>>> http://dev.mygrid.org.uk/wiki/display/developer/Tutorial+-+Service+discovery+plugin
>>> >
>>> > for CWL right ?.
>>>
>>> Yes, the TAVERNA-880 task is basically to implement a service
>>> discovery plugin for CWL.
>>>
>>> The Service Invocation tutorial would be more relevant for
>>> TAVERNA-878.  It could be that to test your UI, to be able to drag a
>>> CWL Tool into a workflow, you need to have a "dummy" Activity similar
>>> to the one in the tutorial, even if it doesn't actually do any actual
>>> invocation when it is run. That is, it would be a placeholder.
>>>
>>>
>>> >  1. SCULF2  workflows are saved as workflow bundle document .
>>>
>>> Correct.. except it's a ZIP file of XML files, not a single document :-)
>>>
>>>
>>> > 2.  Service discovery plugin
>>> > <
>>> http://dev.mygrid.org.uk/wiki/display/developer/Tutorial+-+Service+discovery+plugin
>>> >
>>> > Service
>>> > Description is java bean and it's build using corresponding  workflow
>>> > bundle document .
>>>
>>> It's a java beans (in the Configuration), but as the tutorial is
>>> according to Taverna 2.5 you will later need to update your Service
>>> Discovery code for Taverna 3, where you will use the Taverna Language
>>> SCUFL2 API - which is a java bean approach to the Workflow Bundle.
>>> (those beans are then saved to the Workflow Bundle ZIP file, but that
>>> is already handled).
>>>
>>> The beans are different though, the Taverna 2.5 beans have a
>>> Configuration subclass per activity type, e.g. a ToolConfiguration -
>>> while in Taverna 3 the Configuration class is not subclassed (instead
>>> it declares a type URI), and all the actual configuration is in the
>>> linked JSON object - which content would vary per configuration type.
>>>
>>>
>>>
>>> > 3. Activity has the logic of workflow .For example let's say service is
>>> > addtiion of two numbers . Then two numbers are input and the addition is
>>> > inside the Activity class .
>>>
>>> Exactly, the Activity is the thing that actually 'happens' in a box in
>>> the workflow.  The rest of the workflow is basically connections,
>>> iterations and controls.
>>>
>>>
>>> > 4.Activity class is also configured (build) using  corresponding
>>> workflow
>>> > bundle document .
>>>
>>> Yes. When a WorkflowBundle is set to run, the Taverna Engine will
>>> select the corresponding Activity subclass based on its type URI,
>>> instantiate it, and then configured it with a JsonObject (which exists
>>> as a JSON file if the Workflow Bundle is saved as a ZIP file.)
>>>
>>>
>>> There are different types of activities depending on what kind of
>>> invocation they are doing, e.g. a RESTActivity that can do HTTP calls
>>> (the configuration says which URI and headers), the ToolActivity can
>>> execute a local or SSH command line (the configuration says which
>>> command/host), or the BeanshellActivity can run a Beanshell script
>>> (the configuration contains the script). There are thus different
>>> configuration types, and a corresponding JSON Schema that says which
>>> keys and value types to expect for a given type.
>>>
>>>
>>> The imagined CWLActivity (TAVERNA-878) will be either a new kind of
>>> activity, or just an alternative configuration of the ToolActivity -
>>> as basically a CWL Tool is a command line that in theory may be
>>> executed using the correct "docker run" syntax.   In Taverna 3 it is
>>> possible to have different kinds of configuration for the same
>>> activity, the ToolActivity could be changed to recognize both its
>>> existing "classic" Tool configuration and a new "CWL tool"
>>> configuration.
>>>
>>> If you are interested in this execution logic, then it is probably
>>> worth having an early stage investigation in the beginning of your
>>> GSOC project to see to what extent the existing execution logic of the
>>> ToolActivity can run a docker command line - e.g. experimenting in the
>>> 2.5 Workbench and adding a Tool that executes a tool as in the CWL
>>> Tool description, and then you would be able to see the configuration
>>> mapping in a way.   (But it could be that this reveals that say the
>>> data handling of CWL Tools is different to how the Tool activity
>>> handles input and output files - in which case a new CWLActivity would
>>> be a better approach).
>>>
>>> As you write up your project proposal now, you should have some rough
>>> estimates and time plans. Doing both TAVERNA-878 (activity) and
>>> TAVERNA-880 (discovery) could be too much for the short duration of
>>> GSOC, so if you are interested in both I would suggest to do one of
>>> them only minimally.
>>>
>>>
>>> > *5. when designing a CWL * Service discovery plugin
>>> > <
>>> http://dev.mygrid.org.uk/wiki/display/developer/Tutorial+-+Service+discovery+plugin
>>> >
>>> > i
>>> > Have to implement dummy Activity class for  CWL .
>>>
>>>
>>> Yes, with a "dummy activity" I mean one that can't actually execute
>>> anything, it might just always say "Hello" on the output so that you
>>> can see in the workbench that you have added something from your CWL
>>> Service Discovery plugin.
>>>
>>> Also when you do this in Taverna 2.5 you need to have an actual
>>> Activity subclass to add to the workflow - this is a problem in 2.5 in
>>> that you couldn't build workflows with activities your local Taverna
>>> didn't know how to execute. In Taverna 3 the workflow building is done
>>> with plain java beans from the Taverna Language API, and those don't
>>> know anything about execution, and so there it would be possible to
>>> build workflows with activities that only run elsewhere (e.g. build a
>>> workflow in Windows even though its activity can only run in Linux).
>>>
>>>
>>> Alan - do you think in Taverna 2.5 phase we could let the CWL
>>> Discovery plugin add a DisabledActivity instance and then chuck the
>>> configuration JSON inside the XML? Would not then that XML be saved
>>> directly to the .t2flow?  It would be a bit cheating.. but then this
>>> would be cheating anyway, and also it would mean it would both save
>>> from Taverna Workbench 2 and load in Taverna 3. (We would need to add
>>> a translator on the Taverna Language side though).
>>>
>>> > It should have logic to
>>> > execute cwl-runner with corresponding tool and inputs and get the
>>> output .
>>>
>>>
>>> Executing cwlrunner from Taverna (configured with a CWL workflow
>>> rather than a CWL tool) could be an interesting thing - that would be
>>> a way to include a CWL workflow as a nested workflow in Taverna.
>>> However I think that would be a different approach, so I've tracked
>>> that as a new Jira task
>>> https://issues.apache.org/jira/browse/TAVERNA-938
>>>
>>> This could be some kind of intermediate approach you could explore if
>>> you want, as you can execute any cwl tool by generating a one-step cwl
>>> workflow and run cwlrunner. However then the user would need to have
>>> cwlrunner AND Taverna installed, so it would be more of an
>>> intermediate solution, which would however be great for demonstration
>>> purposes - and mean that your GSOC work would be usable without
>>> waiting for the other tasks.
>>>
>>>
>>> Personally I am also going to try to work on the CWL support during
>>> this spring/summer - so whatever tasks are not picked by an accepted
>>> GSOC student would be something I would try to do - however I wouldn't
>>> want the students to have to rely on this arriving in time, as your
>>> GSOC evaluation (which determines if you get paid!) should be
>>> independent of other concurrent work, including different GSOC
>>> students.  That doesn't mean you can't collaborate and discuss
>>> solutions on this list - I would hope you do! Just don't build other
>>> people's work into your project proposal like a blocker.
>>>
>>>
>>> You are asking the right questions! Feel free to ask if you need help
>>> with your project proposal!
>>>
>>>
>>> --
>>> Stian Soiland-Reyes
>>> Apache Taverna (incubating), Apache Commons RDF (incubating)
>>> http://orcid.org/0000-0001-9842-9718
>>>
>>
>>



-- 
Stian Soiland-Reyes
Apache Taverna (incubating), Apache Commons RDF (incubating)
http://orcid.org/0000-0001-9842-9718

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