Rails deployment for a shared host, multiple developers, zero shared secrets.

Bosun is a .deb-packaged CLI for deploying Rails apps on argus-tty-managed Ubuntu hosts — tiered developer/deployer/admin Linux accounts, a git deploy key shared across the team instead of everyone's personal key, and app secrets locked to a single unprivileged service account, not a shared group.

Launchpad PPA .deb package argus-tty recommended MIT licensed GitHub

The problem bosun actually solves isn't "how do I deploy Rails" — every tool answers that. It's "how do five developers deploy the same box without all sharing root, a personal SSH key, or read access to DATABASE_URL." Bosun provisions each app with its own ACL-locked shared/.env (root + a single service account only, not the group every developer is in), a shared per-app git deploy key instead of N personal keys, and require_role() checks on every subcommand that reuse argus-tty's existing sudoers whitelist — no new sudo privileges are ever granted to deploy an app.

sudo add-apt-repository ppa:yadavramlaxman/argus-tty && sudo add-apt-repository ppa:yadavramlaxman/bosun
sudo apt update && sudo apt install argus-tty bosun   # or the .deb package — see Installing below
sudo bosun bootstrap                                  # one time per host: RVM multi-user

Full install guide, including the .deb-package alternative and verifying the install: Installing.

No argus-tty? Skip the first line — bosun falls back to a single-operator standalone mode automatically: no tiers, no separate service account, one account does everything. A deliberately reduced security posture for one person on their own box, not a lighter-weight substitute for argus-tty on a shared one.

sudo bosun add myapp              # provision /var/www/myapp (admin, one time)
bosun install myapp               # ruby/gemset + OS build deps (developer/admin)
bosun setup myapp                 # releases/shared/config tree (developer/admin)
bosun deploy myapp main           # clone, build, symlink, restart, rollback-on-fail (deployer/admin)

What it does

• Tiered Linux accounts, not one shared deploy user — argus-tty's developer/deployer/admin tiers, enforced per-subcommand by require_role(): a plain developer can't deploy; a plain deployer can't open a Rails console or read secrets.
• Secrets locked to one service account — shared/.env is root:root 600 with a single named-user ACL grant for webapp-svc, not the shared webapps group — a compromised developer/deployer account has no standing read access to DATABASE_URL/SECRET_KEY_BASE at all.
• One shared git deploy key per app — not N personal SSH keys to whitelist (and revoke) on the git host; distributed automatically to every current admin/deployer account.
• Deploy with automatic rollback — clone → bundle install → assets:precompile (elevated to webapp-svc just for that one step, so the deploying account never needs standing secret access) → symlink swap → restart → health check → automatic rollback to the previous release on failure → old-release cleanup.
• Fully overridable per app — copy do-release.sample, edit it: real bash, not a hook/plugin DSL, for a different worker (a sneakers consumer instead of Sidekiq, Docker instead of systemd, extra build steps) — every other app on the box keeps the default untouched. See adding a custom service.

How it compares

Capistrano, Mina, and Kamal all answer "clone, build, symlink, restart" well — that's not where bosun differs. None of the three has a concept of tiered Linux accounts or ACL-locked secrets at all: they assume one deploy identity (a shared SSH key, a CI token) with full access to everything the deploy needs, because they're solving the deploy choreography, not who-on-the-team-can-touch-what on a box several people share.

Capability	Bosun	Capistrano	Mina	Kamal
Tiered developer/deployer/admin accounts	✓	—	—	—
Secrets ACL-locked to one service account	✓	DIY	DIY	DIY
Shared per-app deploy key (not personal)	✓	DIY	DIY	DIY
No new sudo privileges to deploy	✓	n/a	n/a	n/a
Works without Docker	✓	✓	✓	Docker-only
Full bash script override per app	✓	Rake tasks/hooks	Rake tasks	config DSL
Automatic rollback on failed health check	✓	plugin	manual	✓

"DIY"/"n/a" means the tool itself has no opinion here, not that it's impossible to bolt on yourself. Capability cells describe design intent as of this writing, not an independent re-test of every release — re-check before quoting externally.

Documentation

• Installing — Launchpad PPA (recommended) or the .deb package, install order, and verifying the install.
• Walkthrough: setting up a new app from scratch — every command, real sample output, from a fresh host to a first deploy.
• Who can do what — the developer/deployer/admin permission table.
• Provisioning an app — everything bosun add creates on disk, and why.
• Git deploy key — one shared keypair per app, distributed to every admin/deployer account, never a personal key.
• Running Rails commands and tailing logs — bosun run (console/rake/migrations) and bosun logs.
• Customizing deploy for one app — overriding do-release with a full script instead of a hook DSL.
• Adding a custom service — a third long-running process beyond Puma+Sidekiq, in bosun's own format.
• systemd units — what bosun add generates for Puma/Sidekiq, and optional socket activation.
• Scheduled tasks — the /etc/cron.d/<app> format bosun generates.
• Changing an app's Ruby version — safely, on a host where several apps share one RVM install.
• Standalone mode — running bosun with no argus-tty installed.
• Reverse-proxying with nginx — the Puma unix socket config.

Guides

• Why bosun locks secrets to one service account instead of a shared group or box-wide env — the ACL model, and why dotenv-rails was deliberately left out.
• Multi-tenant Rails deployment: deploying without root or a personal SSH key — the developer/deployer/admin tier model and the shared per-app git deploy key, explained.
• A full script override instead of a hook DSL: customizing a Rails deploy pipeline — why do-release.sample is plain bash you copy and edit, not a plugin system to learn.

Links