[Enhancement][zos_copy] Need other behavior when copying a GDG to another GDG

[vcorfmatibm]

Is there an existing issue for this?

• There are no existing issues.

Enhancement or feature description

In use case of Wazi Deploy we want the customer to be able to back up and restore (in case of failure) a GDG with the same properties. A sort of "mirror" of a source.
Could we have a mirror option to copy a GDG to another GDG with the same properties which includes keeping the same GDS names.

Currently when copying a GDG to another GDG the absolute names of the data sets will be:

USER.GDG.TEST1
USER.GDG.TEST1.G0004V00
USER.GDG.TEST1.G0005V00
USER.GDG.TEST1.G0006V00

but when copying to a destination that is resulting in:

USER.GDG.TEST1
USER.GDG.TEST1.G0001V00
USER.GDG.TEST1.G0002V00
USER.GDG.TEST1.G0003V00

However when copying to another not defined GDG in ZOAU the resulting GDG will be:

USER.GDG.TEST1
USER.GDG.TEST1.G0004V00
USER.GDG.TEST1.G0005V00
USER.GDG.TEST1.G0006V00

Ansible module

zos_copy

[fernandofloresg]

After taking a look into this I think this should be the default behavior when a the destination GDG is not existent, that should also be an improvement on performance.

[fernandofloresg]

This it the code section that handles this creation:

    def copy_to_gdg(self, src, dest):
        """
        Copy each allocated generation in src to dest.

        Parameters
        ----------
        src : str
            Name of the source GDG.
        dest : str
            Name of the destination GDG.

        Returns
        ------
        bool
            True if every copy operation was successful, False otherwise.
        """
        src_view = gdgs.GenerationDataGroupView(src)
        generations = src_view.generations()
        dest_generation = f"{dest}(+1)"

        copy_args = {
            "options": ""
        }

        if self.is_binary or self.asa_text:
            copy_args["options"] = "-B"

        for gds in generations:
            rc = datasets.copy(gds.name, dest_generation, **copy_args)

            if rc != 0:
                return False

        return True

Since this behavior is the default for ZOAU's datasets.copy() it should be as simple as calling that method when dest does not exist. Please add a comment on why that check is there to begin with.

Also make sure to add a test case to cover this.