[Info-vax] Restful API w/JSON client package or library on OpenVMS

[Arne Vajhøj]

On 3/20/2024 12:05 AM, Richard Jordan wrote:
> On 3/13/24 5:34 PM, Richard Jordan wrote:
>> One of our customers currently on VSI VMS on Integrity has been using 
>> the GSOAP kit from HP as a client to communicate with a third party 
>> app on windows server.  The company making that product is dropping 
>> SOAP/GSOAP and moving to only support JSON-based Restful API.
>>
>> I see several items that purport to provide a Restful API for 'server' 
>> side use on VMS, like WSIT from VSI.  Client mentions seem to be 
>> relegated to other platforms.  Other options seem to be the same; 
>> server only.
>>
>> Are there any packages, callable libraries, "Netlib" like options, etc 
>> that would allow VMS programs to access restful API servers?  Whether 
>> its encapsulation like the GSOAP kits, or just linking in a callable 
>> library of routines?
>>
>> Major props if it can be called from BASIC without intervening C or 
>> other language.
>>
>> Is VMS Python an option since it looks like Restful API is supported 
>> by recent versions of that language on VMS?  I assume we'd have to get 
>> BASIC to talk to Python to do the communications in that case...
>>
>> Thanks for any suggestions or info.
> 
> Thanks for the responses.  Got a little more info; where the current 
> GSoap implementation is done to the vendor software running on a local 
> server; the new one is cloud (O frabjous day! Callooh! Callay!) so the 
> connection is done to a public server

 From the client programming perspective it does not matter whether
the HTTP goes over 1000 inches of wire or 1000 miles of wire.

External cloud means that the network team need to open the firewalls
for this specific outbound traffic, but they must be doing that for
other traffic already so no big deal.

>                                         with no reasonable option to set 
> up a test account so we can create the software to talk to it on VMS.

No test system is a problem.

But:
* "usually" documentation for RESTful web services contains request
   and response examples and if this one does then creating a server
   simulator is easy
* a "well behaved" RESTful service does not change any state for
   GET requests, so if that is the case then GET requests can be tested
   against the real server (unless data privacy prevents test on real
   data)

And this problem is not VMS specific. Any client in any language on
any OS will have this problem.

> I may find something that can run as a generic server on one of the 
> customer's pc servers so we can test doing 'generic' restful but we'll 
> see.

If you just need to play a little with RESTful web service then
any system is fine to host including your VMS system.

>       More likely we'll end up with some middleware on a local pc server 
> talking to the vendor cloud, and relaying requests from VMS.

That is obviously possible.

But that middleware could run on VMS as well.

Running on those Linux/Windows server greatly increases the
number of tools/frameworks/libraries available, but it could
run on VMS.

Arne