Architecture & Aegir internals

BOA is an omega8cc fork of the Aegir hosting stack, run on Devuan, Nginx-only and Percona-only, in a Master + N-Satellites multi-instance layout that upstream Aegir does not have. This section is the operating reference for that internal model — the layers, the node-type entity graph, the cron-driven task engine, and the multi-Octopus instance model — with every concrete path, variable, and constant verified against current private-dev source rather than the retiring built-in docs.

The instance root is /data/disk/<user> (not /home/oN), the Hostmaster codebase lives at <root>/aegir/distro/NNN (a numeric counter, not hostmaster-7.x-3.x), and Provision is at .drush/sys/provision (the bare .drush/provision path is actively removed). Those three corrections recur throughout — they are the canonical forms.

Pages

  • Architecture overview — the layered front-end / back-end / services view, the Master + Satellite split, the corrected file-system layout, the continuous-runtime cadence table, the install/upgrade flow, and the full upstream-divergence table.
  • Entity & service model — server / service / service-type, platform and site node types, the four real hosting_site status constants, the BOA permissions matrix (0440 / 02775), the entity → provision-* backend mapping, and renameaegirhost.
  • Task queue engine — the cron → runner.sh → per-Octopus aegir.sh → hosting-dispatch chain, fast/slow cadence, the three registered queues (tasks, cron, task_gc), the unused-by-BOA hosting_queued daemon, and the pause/resume + failure controls.
  • Multi-Octopus model — the one-Master / N-Satellites layout, the instance-owner vs o1.ftp lshell identity split, per-instance roots and control files, the isolation boundary, and adding instances with boa in-octopus.
  • Managing Aegir from the command line — driving the back end directly: the provision-* / hosting-task verb set, the front-end-sync guard-rail, what Verify checks per context (server / platform / site), and the --debug diagnostic for a failing task.

See Control files & INI for the variable surface these pages reference, Database and Nginx internals for the host-side service detail, and the Reference appendix for the consolidated variable, path, and command tables. Tools dropped from the stack are recorded in Discontinued features.