Like Apple announced this spring they have now removed many services from their macOS Server.app. There is a nice overview here. There is also a migration guide, that should help with transitioning to some open source alternatives. So far so good.
One thing upfront: the decision to remove those services is sad, but probably based on how they were used (or weren't). And while a UI for configuring those services is nice, it might not justify the amount of work needed from Apple's side. In a nutshell: I'm not critizing the decision here.
The migration guide
Since the profile manager in Server 5.6 on High Sierra seems to have some problems dealing with iOS 12 and macOS Mojave devices, I decided to update my macOS server to Mojave and Server 5.7 this weekend. I needed to migrate / replace DHCP, DNS, VPN, Web and Mail services. As mentioned before, there is a migration guide. Looking through it, I've found that most of them are pretty easy to migrate. So today I started with the migration and migrated DHCP, DNS and VPN services. While the general migration really was only a few steps, it also told me a lot about the migration guide.
It's only made half-hartedly. Lots of copy-pasting happened there. There are mistakes in the listed commands. There are duplicate keys (with contradicting values) in some launch daemon property lists. Overall it really feels like it was done in a rush.
Furthermore, there is no guide on how to set up an Apache web server and use the profile manager in Server 5.7. The migration guide clearly states, that the profile manager has to stay off after the migration described in the document. So essentially, you can't run websites with Server 5.7 if you want to use the profile manager. Unless you're manually dig into the configuration the profile manager does and hack your own configuration around it (what I'll probably do).
Last but not least, there is no guide on how to migrate the mail service. I repeat, the mail service - probably the service with the most user data. I haven't checked, but it seems like every other removed service is covered in the migration guide - except mail. Looking through the config and data directories of the mail service, I cannot help but feel that the mail service is likely the most complicated one. Again, it seems like the migration guide had to be done quickly. And steps to migrate the complex mail service would have just taken too much time.
Dear Apple, if you remove services because they're no longer used enough to justify their development - fine by me. You also started of nicely by listing alternatives. But please put some last effort into it and publish a complete migration guide!