meta/architecture-docs/Fediversity-architecture-notes.md

<!-- Note: we're "abusing" the classDiagram for the moment as we sketch this out -->

```mermaid
graph TB

Core[<b>Core-services</b><br/><small>DNS<br/>Email<br/>identity_management<br/>secret_management<br/>authentication<br/>SASL</small>]


subgraph Management
    Administration[<b>Administration</b><br/><small>monitoring<br/>alerting<br/>graphing<br/>restore_backups</small>]
    Management_UI[<b>Management_UI</b><br/><small>human-oriented<br/>administration<br/>replication<br/>migration</small>]
    NixOps[<b>NixOps</b><br/><small>orchestration</small>]
end


subgraph Hardware
    Systems[<b>Systems</b><br/><small>Storage<br/>Networking<br/>Operating-system<br/>Virtualization</small>]
    Storage[<b>Storage</b><br/><small>exclusive_filesystem<br/>shared_blob<br/>zfs</small>]
end

subgraph Virtualization
    Nixos[<b>Nixos</b><br/><small>Application</small>]
    LinuxOS[<b>LinuxOS</b><br/><small>Application</small>]

    Services[<b>Services</b><br/><small>NextCloud<br/>secure_document_collaboration<br/>Forgejo<br/>webmail<br/>HedgeDoc<br/>project_planning</small>]
    FediServices[<b>FediServices</b><br/><small>Matrix<br/>Pixelfed<br/>Peertube<br/>Mastadon<br/>GotoSocial<br/>activityPub</small>]
end


Systems --> Storage
Hardware --> Virtualization
Virtualization --> Hardware 
Services --> Core
FediServices --> Core
Core --> Hardware
Nixos --> Services
Nixos --> FediServices
Management_UI --> NixOps
Management_UI --> Administration
```

* human-centric
* easy, automated, replication and migration to different datacenter provider
* blob storage replicated generically
* files on the exclusive filesystems replicated via application-aware process, e.g.:
  * asynchronous, but "live" database replication
  * shutdown app then rsync directories
  * ZFS replication and snapshot-ing
* Strengths, Weaknesses, Opportunities, and Threats awareness for all apps
* Not everything needs to start on Nix, NixOs, or with NixOps
* Do not use "Open Core"
  * GitLab
  * Dovcot
  * Zimbra
* LXC containers (not Docker-style)