Can no longer fetch a prestage?

[csfjeff]

I have a backend API that I use to help automate a bunch of stuff - one of which is switching iPads to different prestage enrollments (so I can automate moving them in and out of Shared iPad prestage). It's been working well for a couple years but this morning it's stopped working (I assume something to do with the 11.24.1 JAMF update that was installed this weekend). Basically I'm trying to fetch the prestage and it gives an error.

I've updated my backend so it's on Ruby 3.4.8 and Ruby-JSS 5.0.2 to make sure that I'm working with the newest toolset - it did resolve another error I was seeing in the logs but not this one.

prestage = Jamf::MobileDevicePrestage.fetch displayName: "Default Unassigned"

/usr/local/bundle/gems/ruby-jss-5.0.2/lib/jamf/api/jamf_pro/mixins/jpapi_resource.rb:69:in 'Jamf::JPAPIResource::ClassMethods#new': Use .fetch, .create, or .all(instantiate:true) to instantiate Jamf::JPAPIResource objects (Jamf::UnsupportedError)
        from /usr/local/bundle/gems/ruby-jss-5.0.2/lib/jamf/api/jamf_pro/mixins/collection_resource.rb:534:in 'Jamf::CollectionResource::ClassMethods#fetch'
        from (irb):9:in '<main>'
        from <internal:kernel>:168:in 'Kernel#loop'
        from /usr/local/bundle/gems/padrino-core-0.16.0/lib/padrino-core/cli/base.rb:44:in 'Padrino::Cli::Base#console'
        from /usr/local/bundle/gems/thor-1.3.2/lib/thor/command.rb:28:in 'Thor::Command#run'
        from /usr/local/bundle/gems/thor-1.3.2/lib/thor/invocation.rb:127:in 'Thor::Invocation#invoke_command'
        from /usr/local/bundle/gems/thor-1.3.2/lib/thor.rb:538:in 'Thor.dispatch'
        from /usr/local/bundle/gems/thor-1.3.2/lib/thor/base.rb:584:in 'Thor::Base::ClassMethods#start'
        from /usr/local/bundle/gems/padrino-core-0.16.0/bin/padrino:9:in '<top (required)>'
        from /app/bin/padrino:29:in 'Kernel#load'

If I just do a Jamf::MobileDevicePrestage.all that part works ok, so it seems it's something to do specifically with the fetch command.

[glenfarclas17]

At first glance I suspect its a change in ruby 3.4 (.x) which I haven't had a chance to test with yet :/

For classes embodying collection resources (the 'jamf objects' you can work with via the API), you aren't allowed to use Klass.new to instantiate objects of the class, you have to use .fetch, .create, or .all with the :instantiate parameter set to true.

ruby-jss enforces this by looking at the caller_locations array in an overridingnew class method to ensure its only being called by those other methods, not directly. caller_locations returns the callstack/backtrace leading to the current place in the code.

But you are using .fetch, so it should work as expected - it's reporting that you're not.

If the order or contents of the array returned by caller has changed in ruby 3.4, that could cause what you're seeing.

You can see where its raising that error in line 69 of /usr/local/bundle/gems/ruby-jss-5.0.2/lib/jamf/api/jamf_pro/mixins/jpapi_resource.rb on your machine.

As a blanket test of my suspicion, you can comment out the first 4 lines of that method:

calling_method = caller_locations(1..1).first.label
unless NEW_CALLERS.include? calling_method || data[:instantiate_me
    raise Jamf::UnsupportedError, 'Use .fetch, .create, or .all(instantiate:true) to instantiate Jamf::JPAPIResource objects'
 end

and see if it resolves the problem.

I'll get an updated ruby installed asap and test it myself, but if you beat me to it, let me know what you see.

Cheers!
-Chris