fix(post-install): updating optimizations of both flows prints only its steps

.github/scripts/tests/test_install_functions_sourced_twice.py

@@ -0,0 +1,39 @@
+"""The shared install functions are sourced by both post-install flows. An
+update that runs functions of the two sources the file twice in one shell,
+which has to be as quiet as the first time."""
+
+from pathlib import Path
+import shutil
+import subprocess
+import unittest
+
+ROOT = Path(__file__).resolve().parents[3]
+SHARED = ROOT / "scripts/global/utils-install-functions.sh"
+
+
+@unittest.skipUnless(shutil.which("bash"), "bash is needed")
+class SourcedTwiceTests(unittest.TestCase):
+    def source(self, times):
+        script = "; ".join([f'source "{SHARED}"'] * times) + '; echo "${PMX_NIC_LINK_DIR}|${#PMX_DKMS_COMPONENTS[@]}"'
+        return subprocess.run(["bash", "-c", script], capture_output=True, text=True, check=False)
+
+    def test_a_second_source_prints_nothing(self):
+        once, twice = self.source(1), self.source(2)
+        self.assertEqual(twice.stderr, once.stderr)
+        self.assertNotIn("readonly variable", twice.stderr)
+        self.assertEqual(twice.returncode, 0)
+
+    def test_the_values_are_the_same_and_stay_read_only(self):
+        self.assertEqual(self.source(2).stdout.strip(), "/etc/systemd/network|2")
+        attempt = subprocess.run(["bash", "-c", f'source "{SHARED}"; PMX_NIC_LINK_DIR=/tmp'],
+                                 capture_output=True, text=True, check=False)
+        self.assertIn("readonly variable", attempt.stderr)
+
+    def test_no_other_shared_file_declares_a_read_only_variable_unguarded(self):
+        for path in sorted((ROOT / "scripts/global").glob("*.sh")) + [ROOT / "scripts/utils.sh"]:
+            for line in path.read_text(errors="replace").splitlines():
+                self.assertFalse(line.startswith(("readonly ", "declare -r ")), f"{path.name}: {line[:60]}")
+
+
+if __name__ == "__main__":
+    unittest.main()

scripts/global/utils-install-functions.sh

@@ -102,8 +102,12 @@ install_single_package() {
 # file, so user-authored .link files in /etc/systemd/network/ are
 # never touched.
 
-readonly PMX_NIC_LINK_DIR="/etc/systemd/network"
-readonly PMX_NIC_LINK_MARKER="# Managed by ProxMenux — do not edit"
+# Declared once: this file is sourced by both post-install flows, and an
+# update that runs functions of the two sources it twice in the same shell.
+declare -p PMX_NIC_LINK_DIR >/dev/null 2>&1 \
+    || readonly PMX_NIC_LINK_DIR="/etc/systemd/network"
+declare -p PMX_NIC_LINK_MARKER >/dev/null 2>&1 \
+    || readonly PMX_NIC_LINK_MARKER="# Managed by ProxMenux — do not edit"
 
 # Print the MAC address recorded in a .link file, uppercased, or empty
 # if the file has no MACAddress= line.
@@ -254,13 +258,16 @@ pmx_uninstall_persistent_network() {
 # ProxMenux components against that kernel — so drivers keep
 # working after the reboot without operator intervention.
 
-readonly PMX_COMPONENTS_STATUS="/usr/local/share/proxmenux/components_status.json"
+declare -p PMX_COMPONENTS_STATUS >/dev/null 2>&1 \
+    || readonly PMX_COMPONENTS_STATUS="/usr/local/share/proxmenux/components_status.json"
 
 # component_key : dkms_module_name  (empty module = not DKMS)
-readonly -a PMX_DKMS_COMPONENTS=(
-    "nvidia_driver:nvidia"
-    "coral_driver:gasket"
-)
+if ! declare -p PMX_DKMS_COMPONENTS >/dev/null 2>&1; then
+    readonly -a PMX_DKMS_COMPONENTS=(
+        "nvidia_driver:nvidia"
+        "coral_driver:gasket"
+    )
+fi
 
 # Print the newest installed pve/proxmox kernel version, or empty.
 _pmx_newest_installed_kernel() {