Fix updating pattern and route address

[pwielgolaski]

Updating was not working for pattern and address at all.

[Dieterbe]

i believe we should update updateConn() to take an addr argument, and only when everything succeeds in there, update route.Addr, so that if updateConn fails, route.Addr should remain what it was.
thoughts?
otherwise LGTM

[Dieterbe]

alternatively we could also do it your way, and have route.Addr mean "the address we want it to point to, even if it errors a bit now, we know it should come up later", but then we'd have to implement a mechanism to make sure it keeps trying to connect to the new location; (because now updateConn doesn't update the conn upon failure, so the old conn remains, so there's no reason to reconnect)

and also, if there's a legitimate error (like a typo in a dns name), it could go unnoticed this way.

i think i prefer the stricter mode i mentioned above.

[pwielgolaski]

At the moment it works in this way that it updates and try to connect, if there is problem with connection it is reported to the user with error, but it gives possibility to edit destination is down.

[Dieterbe]

aha indeed, so when there's a problem setting up the connection, we will always tell the user about this.
but still, if the user doesn't fix the problem, the connection will keep pointing to the old location, but route.Addr has the updated address, so they are out of sync, and at some point when it tries to reconnect (for example after connection got dropped for some reason), it will try to connect to route.Addr and fail, and the user will have no idea because this is long after the user was doing changes in the admin ui.

I believe we should only update route.Addr if we are able to update the route's connection with a valid connection to the new address.

[pwielgolaski]

I did extra handling for the case you described, what do you think?

[Dieterbe]

looks good, but updateConn should probably be called updateAddr, which lets you keep the name updateConn for the existing function (there should be no need to rename this to reconnect)

[pwielgolaski]

I changed method as you suggested.

[Dieterbe]

actually, looking more at it now, it would be nice to somehow enforce that if updateConn() is called with an addr that is not route.Addr, and it succeeds, we update route.Addr to the specified address. right now we should always remember this when we call updateConn, which leaves room for mistakes.

I think we can add this robustness and simplify the code by just, at the end of updateConn, if everything succeeded, updating route.Addr to addr. that way we don't need updateAddr at all.

what do you think?

[pwielgolaski]

I changed according to your comments.

[Dieterbe]

thanks @pwielgolaski for your work. looks good.
FYI i pushed two related small fixes 7870c7d and ccdaf13