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projectatomic / container-storage-setup

Service to set up storage for Docker and other container systems
Apache License 2.0
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Cope with atomic upgrade overwriting /etc/sysconfig/docker-storage-setup #271

Closed rhvgoyal closed 6 years ago

rhvgoyal commented 6 years ago

Our current default driver is "devicemapper" and recently it was changed to "overlay2". Normally it works as over upgrades rpms don't overwrite /etc/sysconfig/docker-storage-setup. (It is not a config(noreplace) file).

But atomic does not understand it and overwrites this file over upgrade. That means we are left with a scenario where a devicemapper thin pool is already configured but /etc/sysconfig/docker-storage-setup has STORAGE_DRIVER=overlay2.

This is a corner case. Deal with it. During start, bring up thin pool if one is already configured. And during reset, continue to reset if there is a configured thin pool.

rhvgoyal commented 6 years ago

cc @cgwalters @dustymabe @rhatdan

cgwalters commented 6 years ago

The unhappiness with how ostree handles this in the commit messages aside, this all looks good to me.

(Remember, terminology gets tricky here because today you can do e.g. rpm-ostree override replace ./container-storage-setup.x86_64.rpm - and that still has the same semantics around %posttrans. It's RPM - but handled in a new way. Among other advantages over yum for example, it's still fully transactional. Hence, I tend to use the term "classic" or "yum-managed" systems, and "ostree"/rpm-ostree (or atomic) for the latter.)

rhatdan commented 6 years ago

LGTM. but this is a lot of changes.

rhvgoyal commented 6 years ago

@cgwalters I don't mind new way of doing things as long as it is well published what one can do. Problem is that we are used to do things rpm way and suddenly come to know that what we can do in rpm, is not compatible with rpm-ostree stuff. And suddenly we are hacking to code to work it around after users have reported issues.

To me this all should have been analyzed and addressed when we were switching driver to overlay2. I am not sure why did we let it go and did not think more about it.