systemd owns its package; systemd-networkd configures networkd and claims none

The service manager's package was declared by the networking module, so the
module that is systemd could not own it and had to leave it out. networkd is a
component of systemd: its module configures it. Removing the package resource
from systemd-networkd uninstalls nothing — the host never removes a package
that is not declared absent.

modules/systemd-networkd/module.json

@@ -2,7 +2,6 @@
   "module": "systemd-networkd",
   "version": "1",
   "capabilities": [
-    "package-manager",
     "service-manager",
     "uplink-systemd-networkd"
   ],
@@ -13,17 +12,12 @@
     }
   ],
   "resources": [
-    {
-      "id": "package",
-      "type": "package",
-      "package": "systemd"
-    },
     {
       "id": "config",
       "type": "file",
       "path": "/etc/systemd/network/00-mesh0.network",
       "mode": "0644",
-      "content": "# Managed by the mesh (module systemd-networkd). Replaced on every push; edit\n# the catalogue instead.\n#\n# This machine's uplink is systemd-networkd's, and the mesh asks one thing of it\n# here (novox/hq ADR 0117): leave the private network's interface alone. mesh0\n# is the mesh's; the mesh brings it up and configures it itself. The mesh never\n# declares a link, an address, a route, a wireless network or its credentials,\n# nor a network file for any of this machine's own interfaces \u2014 those are\n# the operator's, and the link they make is the only channel the mesh reaches\n# this machine over.\n#\n# 00-: networkd applies the first .network file, in alphanumeric order across\n# every directory, that matches an interface, and ignores every later one even\n# if it matches too (systemd.network(5), [Match]). A catch-all of the operator's\n# \u2014 Name=*, Type=ether, a file with no [Match] at all \u2014 sorted before\n# this one would claim mesh0 first. 00 sorts before every numbered prefix the\n# man page recommends.\n#\n# Unmanaged=yes: \"no attempts are made to bring up or configure matching links,\n# equivalent to when there are no matching network files\" (systemd.network(5),\n# [Link], since 233). A match that ends the search, and does nothing else.\n#\n# No DNS setting, because none is needed: networkd never writes\n# /etc/resolv.conf. What it learns from a lease it hands only to\n# systemd-resolved, and the resolver file stays whatever resolv-conf wrote.\n# Whether resolved runs, and what it does with that, is the resolver\n# configuration's question, not the uplink's.\n#\n# The service is reloaded when this file changes, never restarted: a restart\n# drops the links networkd holds, this machine's channel to the mesh among them.\n[Match]\nName=mesh0\n\n[Link]\nUnmanaged=yes\n"
+      "content": "# Managed by the mesh (module systemd-networkd). Replaced on every push; edit\n# the catalogue instead.\n#\n# This machine's uplink is systemd-networkd's, and the mesh asks one thing of it\n# here (novox/hq ADR 0117): leave the private network's interface alone. mesh0\n# is the mesh's; the mesh brings it up and configures it itself. The mesh never\n# declares a link, an address, a route, a wireless network or its credentials,\n# nor a network file for any of this machine's own interfaces — those are\n# the operator's, and the link they make is the only channel the mesh reaches\n# this machine over.\n#\n# 00-: networkd applies the first .network file, in alphanumeric order across\n# every directory, that matches an interface, and ignores every later one even\n# if it matches too (systemd.network(5), [Match]). A catch-all of the operator's\n# — Name=*, Type=ether, a file with no [Match] at all — sorted before\n# this one would claim mesh0 first. 00 sorts before every numbered prefix the\n# man page recommends.\n#\n# Unmanaged=yes: \"no attempts are made to bring up or configure matching links,\n# equivalent to when there are no matching network files\" (systemd.network(5),\n# [Link], since 233). A match that ends the search, and does nothing else.\n#\n# No DNS setting, because none is needed: networkd never writes\n# /etc/resolv.conf. What it learns from a lease it hands only to\n# systemd-resolved, and the resolver file stays whatever resolv-conf wrote.\n# Whether resolved runs, and what it does with that, is the resolver\n# configuration's question, not the uplink's.\n#\n# The service is reloaded when this file changes, never restarted: a restart\n# drops the links networkd holds, this machine's channel to the mesh among them.\n[Match]\nName=mesh0\n\n[Link]\nUnmanaged=yes\n"
     },
     {
       "id": "service",

modules/systemd/module.json

@@ -2,7 +2,8 @@
   "module": "systemd",
   "version": "1",
   "capabilities": [
-    "service-manager"
+    "service-manager",
+    "package-manager"
   ],
   "claims": [
     {
@@ -34,5 +35,12 @@
         ]
       }
     ]
+  },
+  "resources": [
+    {
+      "id": "package",
+      "type": "package",
+      "package": "systemd"
     }
+  ]
 }

modules/systemd/test/client.test.ts

@@ -156,9 +156,12 @@ test("a unit's name is never an option", async () => {
   assert.deepEqual(calls[0].args.slice(-2), ["--", "-x*"]);
 });
 
-test("the manifest declares no package — the service manager is always there, and networkd declares it too", () => {
+test("the manifest owns the systemd package — the service manager's own, never a component module's", () => {
   const m = JSON.parse(readFileSync(new URL("../module.json", import.meta.url), "utf8"));
-  assert.ok(!(m.resources ?? []).some((r: { type: string }) => r.type === "package"));
-  assert.ok(!m.capabilities.includes("package-manager"));
+  assert.ok((m.resources ?? []).some((r: { type: string; package?: string }) => r.type === "package" && r.package === "systemd"));
+  assert.ok(m.capabilities.includes("package-manager"));
+  // networkd is a component of systemd and configures it; it never claims the package.
+  const networkd = JSON.parse(readFileSync(new URL("../../systemd-networkd/module.json", import.meta.url), "utf8"));
+  assert.ok(!(networkd.resources ?? []).some((r: { type: string; package?: string }) => r.type === "package" && r.package === "systemd"));
   assert.deepEqual(m.claims[0].serves, ["units", "status", "start", "stop", "restart", "enable", "disable", "journal"]);
 });