WIP: Verify that RHCOS major version matches expected

[cgwalters]

This is just a draft, proposal untested WIP.

I've seen people in the past trying to use the wrong RHCOS
bootimages. I'd like to make that a clean, clear error.
Various weird things can go wrong if e.g. one tries to use
a RHCOS 4.2 bootimage for 4.1 installer.

I'd also like to change this code at least warn if
the bootimage doesn't exactly match what's pinned in the
installer.

Cleaning this up will need to plumb through the pinned
install data into this script.

Also we'll need to add an environment variable like
OPENSHIFT_INSTALL_ALLOW_OS_IMAGE_OVERRIDE which
makes this script not error, so that one can easily
test new RHCOS versions without rebuilding/hacking the
installer.

[cgwalters]

/hold

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[cgwalters]

And this should probably be a separate service that doesn't go in a retry loop, so we fail fast.

[abhinavdahiya]

I'd also like to change this code at least warn if
the bootimage doesn't exactly match what's pinned in the
installer.

that's not advisable or feasible for UPI customers.

I've seen people in the past trying to use the wrong RHCOS
bootimages. I'd like to make that a clean, clear error.
Various weird things can go wrong if e.g. one tries to use
a RHCOS 4.2 bootimage for 4.1 installer.

personally until we support in cluster component that managed the bootimages, this is not the correct stance to make.

[cgwalters]

personally until we support in cluster component that managed the bootimages, this is not the correct stance to make.

This is about the bootstrap image - you're talking about openshift/os#381 which is distinct.

Now, I could imagine that e.g. we could also pivot the bootstrap image. That would make the bootstrap case symmetrical.

But it absolutely doesn't work today to use e.g. the 4.1 bootimage with 4.2 installer (due to crio.service changes at least). So I think it's better to make the code reflect reality.

[cgwalters]

See openshift/enhancements#78 (comment) which would obviate this.

[abhinavdahiya]

Closing due to this being open for a long time, Please feel free to reopen

/close

[openshift-ci-robot]

@abhinavdahiya: Closed this PR.

In response to this:

Closing due to this being open for a long time, Please feel free to reopen

/close

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