feat(ansible): generate_inventory() + fetch_scope_targets() + unit tests

steward/ansible/inventory_gen.py

@@ -0,0 +1,85 @@
+"""Ansible --list inventory generation from DB records."""
+from __future__ import annotations
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from steward.models.ansible_inventory import AnsibleTarget
+
+
+def generate_inventory(targets: list) -> dict:
+    """Build an Ansible --list JSON inventory from a list of AnsibleTarget objects.
+
+    Accepts any objects with .name, .address, .ansible_vars (dict), .groups (list
+    of objects with .name and .ansible_vars). Uses duck typing so unit tests can
+    pass SimpleNamespace objects.
+
+    Var precedence (lowest → highest, matching Ansible default):
+      group vars (sorted alphabetically by group name) → target ansible_vars → ansible_host
+    """
+    inv: dict = {"all": {"hosts": []}, "_meta": {"hostvars": {}}}
+
+    for target in targets:
+        inv["all"]["hosts"].append(target.name)
+
+        # Merge vars: group vars alphabetically, then host vars, then force ansible_host.
+        merged: dict = {}
+        for group in sorted(target.groups, key=lambda g: g.name):
+            merged.update(group.ansible_vars or {})
+        merged.update(target.ansible_vars or {})
+        merged["ansible_host"] = target.address
+
+        inv["_meta"]["hostvars"][target.name] = merged
+
+        for group in target.groups:
+            if group.name not in inv:
+                inv[group.name] = {
+                    "hosts": [],
+                    "vars": dict(group.ansible_vars or {}),
+                }
+            inv[group.name]["hosts"].append(target.name)
+
+    return inv
+
+
+async def fetch_scope_targets(db, scope: str) -> list:
+    """Query AnsibleTarget objects for a given inventory scope string.
+
+    Scopes:
+      steward:all              — every target
+      steward:group:<uuid>     — targets in that group
+      steward:target:<uuid>    — single target by ID
+
+    Returns a list with groups pre-loaded (selectinload). Returns [] for
+    repo:* scopes (caller handles those via legacy path).
+    """
+    from sqlalchemy import select
+    from sqlalchemy.orm import selectinload
+    from steward.models.ansible_inventory import AnsibleTarget, AnsibleGroup
+
+    if scope == "steward:all":
+        stmt = (
+            select(AnsibleTarget)
+            .options(selectinload(AnsibleTarget.groups))
+            .order_by(AnsibleTarget.name)
+        )
+    elif scope.startswith("steward:group:"):
+        group_id = scope[len("steward:group:"):]
+        stmt = (
+            select(AnsibleTarget)
+            .join(AnsibleTarget.groups)
+            .where(AnsibleGroup.id == group_id)
+            .options(selectinload(AnsibleTarget.groups))
+            .order_by(AnsibleTarget.name)
+        )
+    elif scope.startswith("steward:target:"):
+        target_id = scope[len("steward:target:"):]
+        stmt = (
+            select(AnsibleTarget)
+            .where(AnsibleTarget.id == target_id)
+            .options(selectinload(AnsibleTarget.groups))
+        )
+    else:
+        return []
+
+    result = await db.execute(stmt)
+    return list(result.scalars().all())