Ask HN: What's the best self-host social media platform for closed communities?

My friends and family have been looking to keep in touch, and prying them away from Facebook has been difficult. With the recent outage, many of them have started to ask me about self hosted alternatives.

The basic requirements for what they've been asking me have been:

  * Invite Only - New accounts should be restricted to friends/family members that have been directly been invited by an administrator
  * In-Site Media Sharing - Users should be able to upload videos/photos that will only be available to users which have logged into the site
  * Basic feeds/following
  * Direct Messaging between users
  * Editable profiles for contact information
  * Photo albums - sorting photos by events (such as weddings, parties, trips, etc.) would be great, though seems to be less important than the other options.

Thus far the closest thing I've found is Mastodon, which appears to let communities turn off the federation aspect that connects it to other communities. I'm not too familiar though, and the 'seamless account' option which allows you to use one account for unrelated communities makes me worry that I can't actually configure it to be entirely private.

Are there any options that HN can recommend?