Am 27/09/2022 um 09:40 schrieb Stefan Hanreich: > On 9/26/22 17:51, Thomas Lamprecht wrote: >> Am 22/09/2022 um 16:13 schrieb Stefan Hanreich: >>> I have decided to create distinct event types for source/target nodes, since >>> otherwise the same script would run essentially twice on the source/target >>> node. >>> With distinct event types, the hooks should be more flexible in their usage. >> >> just make that a parameter, same flexibility but less cmd explosion and >> complexity. >> >> Also, _iff_ (see reply we keep the CLI entries for pct/qm it should just be >> a single command there, any difference should be handled in the parameters; >> it's internal after all and we want to avoid that there's more internal >> commands then externals someday ;) >> >> Target and source should be part of the parameters on either call (pre/post, >> src/target), it is relevant info and should be easily available. Some param >> info like offline/online migration could be relevant too, but we can always >> extend on that, so in that regard it can be fine to stop smaller, to avoid >> going over board and having to keep all that info for backward compat. Any >> parameter would need to be encoded in the example then. >> > > This is also an option I explored. One thing that I wasn't sure about was > where the scripts run then? Does the pre event run on the source node and the > post event on the target node? Dominik made an interesting point, that it > might actually be desirable the other way around since you might want to do > some setup code in the pre-hook, which would be nice on the target node. It > might also be nice to run some cleanup code on the post-event which would be > more suited to running on the source node.
IMO they both need to run on both, that's the point of a migration hookscript prepare source & target for leaving/incomming guest and then cleanup source & target after the migration happened (failed or not). > > Do you think it would be smart to implement it as positional parameters to > the script? Like 'qm pre-migrate <target> <source>' ? Since there are already > ideas of adding additional contextual information, might it be smarter to > expose all the additional info to the script in a dictionary? Not sure about > this, but I could see us ending up with a situation where you have many > additional variables only accessible by knowing their indexes. This has other > downsides of course.. _if_ we stay with this approach I'd use as much non-positional params as possible. This is an internal command so user facing UX doesn't matter, the only thing that matters is having some flexibility for forward/backward extendability/compat, and there fixed params are worse than none, iow. they have no benefit for a internal, automatic called script. > >> Some more general note, the example is better than nothing, but a nice >> list/table directly in the docs would be really good to have. This could be >> done upfront, before adding new hooks - best for now to duplicate it for >> both CT and VM chapter (if sensible it can live in its own >> guest-hook-list.adoc and just get included twice). Including the example >> script as an appendix would be a nice touch too. > > I looked at the documentation as well and found it a bit lacking, I thought > it would be nice to overhaul this in an additional patch series, after all > the hooks are merged. I figured it might be okay to silently add these > features and document them afterwards in a subsequent patch. I will add a > short documentation section for each hook to the documentation in the > respective patches as well and then we can maybe overhaul/unify them > afterwards. IMO the status quo is best documented before extending it. _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
