[systemd-devel] Smooth upgrades for socket activated services

[Mike Hearn]

> There's currently no mechanism for that. File an RFE issue.

https://github.com/systemd/systemd/issues/26647

> In the "Portable Services" concept we currently assume you update the
> disk image ("DDI") the service is on, and then simply restart the
> service while leaving the socket around.

I've always wanted to understand portable services better. I never
quite grokked if portable services were meant for apps or operating
system level stuff, or if it didn't matter. It also wasn't quite clear
to me how upgrades worked for them either - presumably if you stick
them inside a deb or rpm you have the same problem, or if you rsync up
a new image, etc. It'd be great to have some blog posts that tackle
portable services end-to-end from the perspective of running servers.

> But of course such an approach requires that services are written in a
> way this is possible

Right. I think that'd be quite hard to do especially with servers
written in portable languages that don't expose stuff unavailable on
Windows e.g. the JVM. Also, from the perspective of a packaging
tool/docker alternative, asking users to add major new features to
their servers is a non-starter. You don't need to do that stuff with
containers.