I'm happily running with v2 using dynamic config files for each of my services.
I use the Headers routing rule extensively to direct traffic to the correct services.
I have found that it is pretty much impossible to upgrade to v3!
If I upgrade first then all my routing stops working as the Headers rule no longer exists - so none of these services get routed at all.
If I change my config first then all my routing stops working as the newly-renamed Header rule doesn't exist for v2 so none of these services get routed at all.
Not really a problem on dev systems, but it means my production systems would have downtime until both sets of changes are done. Alternatively I could create an entirely new docker swarm cluster using v3 with all the new rules syntax, switch it over in DNS, and then de-commission the older cluster.
Anybody know enough about the system to know where to make the change to add support back for Headers (and HeadersRegexp, and any other unnecessarily broken bits)? If we do this then it gives people a chance to upgrade, change config, and then later these can be removed again.
Things should be deprecated first and removed much later. Just breaking stuff for the hell of it is incredibly poor form.
