Multi-Server Deployments: Environments and Server Groups

One server per environment

The common case — staging on one box, production on another:

environments:
  staging:
    server: staging-box
    domain: staging.example.com
  production:
    server: prod-box
    domain: app.example.com

neo deploy --to production

Several servers behind one environment

servers: (plural) fans one environment out to a group — the same app, load-balanced across machines that don't share state:

environments:
  production:
    servers: [web-1, web-2, web-3]
    domain: app.example.com

neo deploy --to production --all     # every server in the group
neo deploy --to production --server web-2   # just one member, for a targeted fix

Why a bare --to production refuses to run here

If production names more than one server, deploying to "the active server" would silently ship to whichever one machine happens to be selected locally — a partial rollout nobody asked for. Neo stops instead:

✗ environment "production" targets 3 servers: web-1, web-2, web-3
  → Deploy the whole group with 'neo deploy --all', or pick one with '--server <name>'.

neo servers and neo use

neo servers          # list every configured server, mark the active one
neo use staging-box  # switch which server plain `neo deploy` targets

--server always overrides the active server for one command, without changing what neo use last selected — useful for a one-off check against a machine you don't normally deploy to.