[Samba] testing upgrades in containers?

[Robert Marcano]

On 11/27/18 4:00 PM, Stefan G. Weichinger via samba wrote:
> 
> While I wait for upgrading 2 customers from 4.8.6 to 4.9.x (hesitating
> not to break things) and checking the list for Louis publishing the
> 4.8.7 stretch packages ... ;-) - thanks, Louis!! - I once again wonder
> how to optimize these updates and minimize the risk of breaking things.
> 
> One thought is to add a test DC to my ADS/samba-domains, running in a
> docker container, testing the upgrade there and throw away the container
> when things are done etc
> 
> Does anyone do that?

With a test environment with two clients, a Windows machine (on the same 
host as a VM, and the host running the container is joined as a file 
server to the domain running on the container:

1) Shutdown the DC container
2) Backup everything on the mounted volumes of the container where the 
Samba data is stored (tar --acls --xattrs ...)
3) Recreate the container with the new Samba release
4) Run the tests
5) If there are failures, revert date from the backup

Why not test everything on VMs as another response asked? because we run 
the DC on containers (mutiple independent domains on different networks)

Note: On those production DCs we backup too the DC container data 
volumes just in case, this time with a snapshot but it is irrelevant, 
tar should work too. The important thing is the DC should be down when 
the snapshot or tar is created

> 
> I know I already asked that here in september (feels as if it was way
> earlier):
> 
> https://lists.samba.org/archive/samba/2018-September/217906.html
> 
> Maybe I set up a 4.8.6 container and test the upgrading in there.
> 
> Feedback welcome.
>