feat(multi-site): spoke.env.example + CFG_PUBLIC_DOMAIN

A dedicated spoke.env for the join-a-cluster vars (CFG_MASTER_DIRECTORY_URL/
_JOIN_KEY, CFG_SPOKE_NO_INBOUND/_PUBLIC_HOST, CFG_PUBLIC_DOMAIN), split out
of setup.env purely for clarity -- setup.env still has every option and
keeps working as a single file if that's preferred. setup.sh reads both
(setup.env first, spoke.env layered on top so its values win), same
first-run-only rule as setup.env already had.

Also adds CFG_PUBLIC_DOMAIN (documented in MULTI_SITE_SPEC.md §4 but never
actually wired into setup.sh): an inbound spoke/standalone site's own public
web domain, independent of CFG_DOMAIN (the shared LDAP identity namespace,
which must stay identical across every site). Unset behaves exactly as
before -- hostnames derive from CFG_DOMAIN like any standalone install.

.gitignore

@@ -19,6 +19,11 @@ proxy.env
 # per-deployment and is not committed.
 setup.env
 
+# spoke.env — same rule as setup.env, but for the join-a-cluster vars split
+# out for clarity (spoke.env.example IS committed). Holds a real site join
+# key once filled in.
+spoke.env
+
 # Backup artifacts (hold secrets — the whole user directory + Redis dumps)
 *.rdb
 *.ldif

docs/MULTI_SITE_SPEC.md

@@ -256,7 +256,7 @@ See [`AGENT_LOCAL_DISCOVERY_SPEC.md`](./AGENT_LOCAL_DISCOVERY_SPEC.md) — split
 | Join key issuance + one-time directory adoption | **Shipped** — `/api/site/join-keys`, `/api/site/export`, `/api/site/join`, fresh-install-gated (v2.2.0–v2.3.0) |
 | Spoke read-only enforcement | **Shipped** — directory-write routes 403 toward the master once joined (v2.3.0) |
 | WAN health check | **Shipped** — `/api/site/ping`, live in the Master Site modal (v2.2.0–v2.3.0) |
-| `setup.env` / `setup.sh` join wiring | **Shipped** — `CFG_MASTER_DIRECTORY_URL` / `CFG_MASTER_DIRECTORY_JOIN_KEY`, `bootstrap/site-join.js` (theta-suite v2.2.0) |
+| `setup.env` / `setup.sh` join wiring | **Shipped** — `CFG_MASTER_DIRECTORY_URL` / `CFG_MASTER_DIRECTORY_JOIN_KEY`, `bootstrap/site-join.js` (theta-suite v2.2.0). Also readable from a dedicated `spoke.env` (`spoke.env.example`, layered on top of `setup.env`) for operators who want join-a-cluster config kept separate from the rest of first-run setup. |
 | Continuous/live replication (vs. one-time export-on-join) | **Shipped** (`sso-manager-node`) — a spoke registers its own endpoint at join time (`POST /api/site/spokes`), and every successful master catalog write fires a fire-and-forget push (`utils/site_replicate.js`) at every registered spoke, which re-pulls a fresh export. Verified end-to-end in `docker-compose.multisite-e2e.yml`. |
 | Identical-directory signing key | **Shipped** — `POST /api/site/export` includes the master's agent-signing key; a spoke adopts it via `agent_keys.adopt()` on join and every resync. OpenBao secret replication *beyond* this one key is still not built. |
 | Coordinated master promotion (demote the old master as one action) | **Shipped** — `POST /api/site/demote` + `site-promote`'s handoff logic. Fixed two real pre-existing bugs while wiring this in: `site-promote`'s god_admin check read a `req.user.groups` field nothing ever populated (permanently 403'd for everyone), and the read-only write-gate 403'd `site-promote` itself before the handler could run. |

docs/sso/multi-site.md

@@ -38,8 +38,13 @@ between the two.
    admin, no enrolled agents), either:
    - Paste the master's URL and the join key into the Master Site modal's
      **Join an Existing Site** form, or
-   - Set `CFG_MASTER_DIRECTORY_URL` / `CFG_MASTER_DIRECTORY_JOIN_KEY` in
+   - Set `CFG_MASTER_DIRECTORY_URL` / `CFG_MASTER_DIRECTORY_JOIN_KEY` before
-     `setup.env` before the first `./setup.sh` run.
+     the first `./setup.sh` run -- either in `setup.env` (which has every
+     option), or in a dedicated `spoke.env` (`cp spoke.env.example spoke.env`)
+     if you'd rather keep join-a-cluster config separate from the rest of the
+     stack's setup. Both are read; `spoke.env`'s values win on a conflict.
+     No public IP on this site at all? `spoke.env.example` also covers the
+     no-inbound relay vars (`CFG_SPOKE_NO_INBOUND`/`CFG_SPOKE_PUBLIC_HOST`).
 3. The spoke pulls the master's full export (LDAP tree, resource catalog,
    agent-signing key) and adopts it, then registers its own reachable URL
    with the master so it can receive live updates going forward.

setup.env.example

@@ -61,9 +61,19 @@ CFG_DOMAIN=example.com
 # being a one-time snapshot -- the master must be able to reach THIS site's
 # CFG_SSO_HOST for that part to work; if it can't (this site has no inbound
 # path), the join still succeeds, it just never receives live updates.
+#
+# All of these (and the no-inbound relay pair below) also live in their own
+# spoke.env.example, if you'd rather keep join-a-cluster config in a
+# dedicated file instead of here -- both are read, spoke.env's values win.
 #CFG_MASTER_DIRECTORY_URL=https://sso.master.example.com
 #CFG_MASTER_DIRECTORY_JOIN_KEY=stj_9f2e...
 
+# This site's own public web domain, independent of CFG_DOMAIN above (the
+# shared LDAP identity namespace, which must be identical across every site).
+# Optional -- only meaningful for an inbound spoke/standalone site that wants
+# its own domain rather than sharing the master's.
+#CFG_PUBLIC_DOMAIN=branch2.example.com
+
 # No public IP at all (CGNAT, etc.)? The master can still reach this spoke by
 # relaying over the gateway-to-gateway WireGuard mesh instead of the open
 # internet (MULTI_SITE_SPEC.md §5.2) -- but the mesh peering itself is a

setup.sh

@@ -200,6 +200,10 @@ fi
 # later steps can use it. The authoritative CFG_* for secrets are still
 # resolved in ensure_config; this is only the hostname override.
 [[ -f ./setup.env ]] && parse_kv_file ./setup.env
+# spoke.env (optional, see spoke.env.example): the join-a-cluster vars split
+# out of setup.env for clarity, layered on top so its values win over any
+# same-named ones in setup.env. Same first-run-only rule as setup.env below.
+[[ -f ./spoke.env ]] && parse_kv_file ./spoke.env
 export CFG_JUMP_HOST
 CFG_CREATE_ALL_HTTP="${CFG_CREATE_ALL_HTTP:-0}"
 export CFG_CREATE_ALL_HTTP
@@ -467,6 +471,10 @@ BAOEOF
 		info "Reading domain/hosts from ./setup.env ..."
 		parse_kv_file ./setup.env
 	fi
+	if [[ -f ./spoke.env ]]; then
+		info "Reading multi-site join config from ./spoke.env ..."
+		parse_kv_file ./spoke.env
+	fi
 
 	# Bind the CFG_* vars to empty where setup.env / the environment didn't set
 	# them, so the .env migration's `${LDAP_X:-$CFG_X}` defaults below don't trip
@@ -540,8 +548,14 @@ BAOEOF
 	[[ -n "$CFG_DOMAIN" ]] \
 		|| die "First run: 'cp setup.env.example setup.env', set CFG_DOMAIN to your domain (e.g. example.com), then re-run ./setup.sh"
 	CFG_BASE_DN="${CFG_BASE_DN:-$(dn_from_domain "$CFG_DOMAIN")}"
-	CFG_SSO_HOST="${CFG_SSO_HOST:-sso.$CFG_DOMAIN}"
+	# CFG_PUBLIC_DOMAIN (MULTI_SITE_SPEC.md §4): an inbound spoke's own public
-	CFG_PROXY_HOST="${CFG_PROXY_HOST:-proxy.$CFG_DOMAIN}"
+	# web domain, independent of CFG_DOMAIN. CFG_DOMAIN is the LDAP identity
+	# namespace and MUST be identical across every site (MMR replicas can't
+	# diverge on base DN) -- CFG_PUBLIC_DOMAIN only changes where the web
+	# hostnames point, never the DN. Unset (the default): behaves exactly as
+	# before, hostnames derive from CFG_DOMAIN like any standalone install.
+	CFG_SSO_HOST="${CFG_SSO_HOST:-sso.${CFG_PUBLIC_DOMAIN:-$CFG_DOMAIN}}"
+	CFG_PROXY_HOST="${CFG_PROXY_HOST:-proxy.${CFG_PUBLIC_DOMAIN:-$CFG_DOMAIN}}"
 	CFG_SITE_NAME="${CFG_SITE_NAME:-local}"
 	# Multi-site identity (site_config.js's `siteSlug`, shown on the Directory's
 	# Multi-Site modal) -- without this it's never set anywhere and every fresh

spoke.env.example

@@ -0,0 +1,54 @@
+# ─────────────────────────────────────────────────────────────────────────────
+# spoke.env — join this stack to an existing Theta Directory as a read-only
+# spoke, instead of seeding a fresh master (MULTI_SITE_SPEC.md).
+#
+# This is the ONE place the join-a-cluster vars live -- split out of
+# setup.env.example (which still has every option, including these, for a
+# single-file bring-up) purely for clarity: standing up a spoke is a distinct
+# operation from configuring a fresh install, so it gets its own small file
+# instead of being buried among unrelated options. Set what you need here;
+# everything else (domain, admin creds, SMTP, ...) still comes from setup.env
+# as normal -- copy setup.env.example too and fill in CFG_DOMAIN there first.
+#
+# Same first-run-only rule as setup.env: read once (layered on top of
+# setup.env, so a var set in both places takes this file's value), then
+# ignored once ./config/ exists -- an already-running directory can never be
+# merged into a master's this way. The one exception is the no-inbound relay
+# vars at the bottom, which setup.sh re-checks on every run (see their
+# comment) since mesh peering usually finishes after the first bring-up.
+#
+#   cp setup.env.example setup.env   # if you haven't already -- set CFG_DOMAIN
+#   cp spoke.env.example spoke.env
+#   $EDITOR spoke.env                # set CFG_MASTER_DIRECTORY_URL + _JOIN_KEY below
+#   ./setup.sh
+#
+# Copying this file to spoke.env (gitignored) keeps your join key out of git.
+# ─────────────────────────────────────────────────────────────────────────────
+
+# The master's URL and a site join key. Mint a key on the master:
+# Directory -> the Master Site modal -> Site Join Keys -> Mint key.
+# Both required to join; if either is unset this stack seeds a fresh master
+# instead (setup.env.example's normal behavior).
+CFG_MASTER_DIRECTORY_URL=https://sso.master.example.com
+CFG_MASTER_DIRECTORY_JOIN_KEY=stj_9f2e...
+
+# This spoke's own public web domain, if it needs one independent of the
+# master's (an inbound spoke serving its own traffic directly -- see
+# CFG_SPOKE_NO_INBOUND below for the opposite case). Optional: CFG_DOMAIN
+# (in setup.env) is the shared LDAP identity namespace and must be identical
+# across every site in the cluster -- this only changes where THIS site's own
+# web hostnames (sso.*, proxy.*) point, never the LDAP base DN.
+#CFG_PUBLIC_DOMAIN=branch2.example.com
+
+# No public IP at all (CGNAT, etc.)? The master can still reach this spoke by
+# relaying over the gateway-to-gateway WireGuard mesh instead of the open
+# internet (MULTI_SITE_SPEC.md §5.2) -- but the mesh peering itself is a
+# manual, out-of-band step on BOTH jump-hosts (mint a mesh join token on the
+# master's jump-host, paste it into this site's jump-host "Join a mesh" UI
+# action) that can't run unattended inside this script. Once that's done, set
+# these two and re-run setup.sh: it discovers this jump-host's assigned mesh
+# IP and registers it with the master, which then auto-creates the relay
+# route on its own theta-proxy. Safe to leave set before meshing -- setup.sh
+# just reports "not meshed yet" and skips until a later re-run finds the IP.
+#CFG_SPOKE_NO_INBOUND=true
+#CFG_SPOKE_PUBLIC_HOST=sso-branch2.master-domain.example.com