Disable node discovery by default

[dtantsur]

Discovery of new nodes requires explicit support from BMO, which
does not seem to exist, nor is on the roadmap. Having discovery
enabled may cause hard to debug situations when an accidentally
booted IPA results in a new node added.

An option is left to enable discovery for testing purposes or
for future implementation on the BMO side.

[dtantsur]

/assign @maelk

Do you folks use this feature? We do not, and it seems to cause problems from time to time.

/cc @hardys
/test-integration

[hardys]

AFAIK we don't yet have any support for discovery at the BMO level - it has been discussed in metal3-io/baremetal-operator#41 and metal3-io/metal3-docs#98 but I'm not aware of any plans to complete that work in the near future.

It might be helpful to explain the motivation here, which is that in some circumstances it's possible for IPA to boot and create a port/node in Ironic before inspection is triggered by metal3, then we get a "Port already exists" error which is sometimes confusing for users.

If this change of config helps with that I'm in favor of disabling discovery for now, then if/when we add discovery to BMO we can figure out a smarter way to deal with these kinds of edge cases.

@dhellmann what are your thoughts?

[metal3-io-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dtantsur, elfosardo

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [dtantsur]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[elfosardo]

/lgtm

[dhellmann]

What effect does this have on inspection? If a host PXE boots the IPA image will inspection still run automatically? Will the data be saved?

[dtantsur]

What effect does this have on inspection?

Inspection can still be requested explicitly, but won't happen accidentally.