src/core/manager.c: log preset activity on first boot

This gives us a little more information about what units were enabled
or disabled on that first boot and will be useful for OS developers
tracking down the source of unit state.

An example with this enabled looks like:

```
NET: Registered PF_VSOCK protocol family
systemd[1]: Applying preset policy.
systemd[1]: Unit /etc/systemd/system/dnsmasq.service is masked, ignoring.
systemd[1]: Unit /etc/systemd/system/systemd-repart.service is masked, ignoring.
systemd[1]: Removed '/etc/systemd/system/sockets.target.wants/systemd-resolved-monitor.socket'.
systemd[1]: Removed '/etc/systemd/system/sockets.target.wants/systemd-resolved-varlink.socket'.
systemd[1]: Created symlink '/etc/systemd/system/multi-user.target.wants/var-mnt-workdir.mount' → '/etc/systemd/system/var-mnt-workdir.mount'.
systemd[1]: Created symlink '/etc/systemd/system/multi-user.target.wants/var-mnt-workdir\x2dtmp.mount' → '/etc/systemd/system/var-mnt-workdir\x2dtmp.mount'.
systemd[1]: Created symlink '/etc/systemd/system/afterburn-sshkeys.target.requires/afterburn-sshkeys@core.service' → '/usr/lib/systemd/system/afterburn-sshkeys@.service'.
systemd[1]: Created symlink '/etc/systemd/system/sockets.target.wants/systemd-resolved-varlink.socket' → '/usr/lib/systemd/system/systemd-resolved-varlink.socket'.
systemd[1]: Created symlink '/etc/systemd/system/sockets.target.wants/systemd-resolved-monitor.socket' → '/usr/lib/systemd/system/systemd-resolved-monitor.socket'.
systemd[1]: Populated /etc with preset unit settings.
```

Considering it only happens on first boot and not on every boot I think
the extra information is worth the extra verbosity in the logs just for
that boot.

diff --git a/src/core/manager.c b/src/core/manager.c
index 4b0f85273ec5fe09f9543ff37e0ff614d97cd019..981c2dc1471b48cb9b69410bf319550a0dbd509b 100644 (file)
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1893,8 +1893,15 @@ static void manager_preset_all(Manager *m) {
         /* If this is the first boot, and we are in the host system, then preset everything */
         UnitFilePresetMode mode =
                 ENABLE_FIRST_BOOT_FULL_PRESET ? UNIT_FILE_PRESET_FULL : UNIT_FILE_PRESET_ENABLE_ONLY;
+        InstallChange *changes = NULL;
+        size_t n_changes = 0;
 
-        r = unit_file_preset_all(RUNTIME_SCOPE_SYSTEM, 0, NULL, mode, NULL, NULL);
+        CLEANUP_ARRAY(changes, n_changes, install_changes_free);
+
+        log_info("Applying preset policy.");
+        r = unit_file_preset_all(RUNTIME_SCOPE_SYSTEM, /* file_flags = */ 0,
+                                 /* root_dir = */ NULL, mode, &changes, &n_changes);
+        install_changes_dump(r, "preset", changes, n_changes, /* quiet = */ false);
         if (r < 0)
                 log_full_errno(r == -EEXIST ? LOG_NOTICE : LOG_WARNING, r,
                                "Failed to populate /etc with preset unit settings, ignoring: %m");