fix(host_agent): provision/deploy vars shadowed by play-var precedence

The assertion failed ("Pass steward_url/token/pubkey") because those were
injected as inventory HOST vars, but the playbooks declared them in the play
`vars:` block — and play vars OUTRANK inventory host vars, so the empty
defaults won and the injected values never reached the play.

- Pass globals (steward_url, steward_pubkey, steward_user, agent_interval) as
  extra-vars via the JSON -e @file (highest precedence, space-safe). Keep only
  the per-host steward_token as an inventory host var.
- provision.yml / install.yml: drop steward_token from `vars:` so the host var
  isn't shadowed; assertions use `| default('')` for the un-defaulted token.

This was the next layer under the inventory-format fix — first the inventory
wouldn't parse, now the injected vars actually apply.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plugins/host_agent/routes.py

@@ -741,10 +741,9 @@ async def deploy_via_ansible():
             host = await _ensure_host_for_target(db, t)
             tokens[t.name] = await _mint_registration_token(db, host)
         inv = generate_inventory(targets)  # built while ORM objects are still live
+        # Per-host token as a host var; steward_url goes in as an extra-var below.
         for name, tok in tokens.items():
-            hv = inv["_meta"]["hostvars"].setdefault(name, {})
-            hv["steward_url"] = url
-            hv["steward_token"] = tok
+            inv["_meta"]["hostvars"].setdefault(name, {})["steward_token"] = tok
         inventory_content = inventory_to_yaml(inv)
         await db.commit()
 
@@ -756,7 +755,8 @@ async def deploy_via_ansible():
         playbook_path="host_agent/install.yml",
         inventory_content=inventory_content,
         inventory_scope=scope,
-        params={"extra_vars": [f"agent_interval={interval}"]},
+        # extra-vars outrank the playbook's `vars:` defaults; token stays per-host.
+        params={"extra_vars_map": {"steward_url": url, "agent_interval": interval}},
         triggered_by=session.get("user_id"),
     )
     if err:
@@ -817,15 +817,10 @@ async def provision_via_ansible():
             host = await _ensure_host_for_target(db, t)
             tokens[t.name] = await _mint_registration_token(db, host)
         inv = generate_inventory(targets)  # built while ORM objects are still live
+        # Only the per-host token is a host var; the globals go in as extra-vars
+        # below (extra-vars outrank play vars, host vars do not).
         for name, tok in tokens.items():
-            hv = inv["_meta"]["hostvars"].setdefault(name, {})
-            hv["steward_url"] = url
-            hv["steward_token"] = tok
-            # Pubkey carries a space (the comment) and steward_user is free text —
-            # injected as JSON hostvars (space-safe), NOT -e k=v strings which
-            # Ansible would shlex-split on whitespace.
-            hv["steward_pubkey"] = pubkey
-            hv["steward_user"] = steward_user
+            inv["_meta"]["hostvars"].setdefault(name, {})["steward_token"] = tok
         inventory_content = inventory_to_yaml(inv)
         await db.commit()
 
@@ -837,7 +832,14 @@ async def provision_via_ansible():
         playbook_path="host_agent/provision.yml",
         inventory_content=inventory_content,
         inventory_scope=scope,
-        params={"extra_vars": [f"agent_interval={interval}"]},
+        # extra_vars_map → a JSON -e @file: highest precedence (beats play vars)
+        # and space-safe (steward_pubkey carries a comment with a space).
+        params={"extra_vars_map": {
+            "steward_url": url,
+            "steward_pubkey": pubkey,
+            "steward_user": steward_user,
+            "agent_interval": interval,
+        }},
         triggered_by=session.get("user_id"),
         connection={"user": boot_user, "password": boot_password},
     )

steward/ansible/bundled/host_agent/install.yml

@@ -7,17 +7,18 @@
   hosts: all
   become: true
   gather_facts: false
+  # steward_token is a per-host inventory var — not declared here, or a play var
+  # would outrank and shadow it. steward_url arrives as an extra-var.
   vars:
     steward_url: ""
-    steward_token: ""
     agent_interval: 30
   tasks:
     - name: Require steward_url and steward_token
       ansible.builtin.assert:
         that:
-          - steward_url | length > 0
-          - steward_token | length > 0
-        fail_msg: "Pass steward_url and steward_token as extra-vars."
+          - steward_url | default('') | length > 0
+          - steward_token | default('') | length > 0
+        fail_msg: "Pass steward_url and steward_token (Steward injects these)."
 
     - name: Create steward-agent system user
       ansible.builtin.user:

steward/ansible/bundled/host_agent/provision.yml

@@ -19,9 +19,12 @@
   hosts: all
   become: true
   gather_facts: false
+  # steward_token is injected as a per-host inventory var (it differs per host),
+  # so it must NOT be declared here — a play var would outrank the inventory var
+  # and shadow it. The globals below arrive as extra-vars (highest precedence),
+  # which override these defaults.
   vars:
     steward_url: ""
-    steward_token: ""
     steward_pubkey: ""
     steward_user: steward
     agent_interval: 30
@@ -29,10 +32,10 @@
     - name: Require provisioning vars
       ansible.builtin.assert:
         that:
-          - steward_url | length > 0
-          - steward_token | length > 0
-          - steward_pubkey | length > 0
-        fail_msg: "Pass steward_url, steward_token and steward_pubkey as extra-vars."
+          - steward_url | default('') | length > 0
+          - steward_token | default('') | length > 0
+          - steward_pubkey | default('') | length > 0
+        fail_msg: "Pass steward_url, steward_token and steward_pubkey (Steward injects these)."
 
     # ── Managed login account ────────────────────────────────────────────────
     - name: Create the steward management account