You’ll access those through the View menu.

Open Directory and Software Update aren’t in the Services or Advanced area of the Server sidebar.

Alerts, Certificates, Logs, Stats, creating users, Calendar, Contacts, Mail, Messages, VPN, Websites, Wiki, DHCP, DNS, and Xsan haven’t changed in forevers, and remain pretty static in this version.

Running the Wiki service configures passwords to use a less secure way of storing passwords.

If you’re running Calendar, Contacts, and/or Mail, then you should consider moving to Google Apps or Office 365.

But you can’t NetRestore an HFS+ volume onto an APFS volume or High Sierra on APFS onto a volume running HFS+. You can do a NetRestore (and Define NetRestore Sources for NetBoot) from a volume that’s already been converted to APFS to another volume that’s already been converted to APFS. You can run a NetInstall to install High Sierra onto clients (which does the firmware update). Because you need to run a firmware update for High Sierra (and APFS), there are caveats to imaging. You can still leverage third party tools to get build automations in place, but this is no longer a built-in component of macOS Server.

A share that Time Machine on client systems can backup to.

Time Machine service is gone, so if you were relying on that, rethink your backup strategy.

Even though the file sharing services are not in the Server app, you can still configure ACLs using the Storage tab under the server’s main screen. You can choose not to upgrade to APFS using the command line to upgrade a server. You cannot share APFS volumes over AFP, so if you’re running file services, make sure you’re aware of that.

During the upgrade to High Sierra, if the operating system is running on a solid state drive, the drive will automatically upgrade to APFS.

As always, make a clone of your computer before upgrading.The latest version of the Apple Server app is out (macOS Server 5.4), and before you upgrade, there are a few points to review:

Update macos 10.13