docs: move /var/log/README to a tmpfiles.d symlink

This moves the /var/log/README content out of /var and into the
docs location, replacing the previous file with a symlink
created through a tmpfiles.d entry.

TODO

@@ -378,9 +378,8 @@ Features:
   https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-wake-sources
   at the end).
 
-* We should probably replace /var/log/README, /etc/rc.d/README with symlinks
-  that are linked to these places instead of copied. After all they are
-  constant vendor data.
+* We should probably replace /etc/rc.d/README with a symlink to doc
+  content. After all it is constant vendor data.
 
 * maybe add kernel cmdline params: to force random seed crediting
 

docs/var-log/meson.build

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: LGPL-2.1-or-later
 
 if conf.get('HAVE_SYSV_COMPAT') == 1 and get_option('create-log-dirs')
-        install_data('README',
-                     install_dir : '/var/log')
+        install_data('README.logs',
+                     install_dir : docdir)
 endif

meson.build

@@ -91,6 +91,7 @@ sysvinit_path = get_option('sysvinit-path')
 sysvrcnd_path = get_option('sysvrcnd-path')
 conf.set10('HAVE_SYSV_COMPAT', sysvinit_path != '' and sysvrcnd_path != '',
            description : 'SysV init scripts and rcN.d links are supported')
+conf.set10('CREATE_LOG_DIRS', get_option('create-log-dirs'))
 
 if get_option('hibernate') and not get_option('initrd')
         error('hibernate depends on initrd')
@@ -215,6 +216,7 @@ conf.set_quoted('BINFMT_DIR',                                 binfmtdir)
 conf.set_quoted('BOOTLIBDIR',                                 bootlibdir)
 conf.set_quoted('CATALOG_DATABASE',                           join_paths(catalogstatedir, 'database'))
 conf.set_quoted('CERTIFICATE_ROOT',                           get_option('certificate-root'))
+conf.set_quoted('DOC_DIR',                                    docdir)
 conf.set_quoted('DOCUMENT_ROOT',                              join_paths(pkgdatadir, 'gatewayd'))
 conf.set_quoted('ENVIRONMENT_DIR',                            environmentdir)
 conf.set_quoted('INCLUDE_DIR',                                includedir)

tmpfiles.d/legacy.conf.in

@@ -12,6 +12,9 @@
 
 d /run/lock 0755 root root -
 L /var/lock - - - - ../run/lock
+{% if CREATE_LOG_DIRS %}
+L /var/log/README - - - - ../..{{DOC_DIR}}/README.logs
+{% endif %}
 
 # /run/lock/subsys is used for serializing SysV service execution, and
 # hence without use on SysV-less systems.

tmpfiles.d/meson.build

@@ -12,7 +12,6 @@ files = [['README',               ''],
          ['systemd-pstore.conf',  'ENABLE_PSTORE'],
          ['tmp.conf',             ''],
          ['x11.conf',             ''],
-         ['legacy.conf',          'HAVE_SYSV_COMPAT'],
         ]
 
 foreach pair : files
@@ -26,21 +25,30 @@ foreach pair : files
         endif
 endforeach
 
-in_files = ['etc.conf',
-            'static-nodes-permissions.conf',
-            'systemd.conf',
-            'var.conf']
+in_files = [['etc.conf',                      ''],
+            ['legacy.conf',                   'HAVE_SYSV_COMPAT'],
+            ['static-nodes-permissions.conf', ''],
+            ['systemd.conf',                  ''],
+            ['var.conf',                      ''],
+           ]
 
-foreach file : in_files
-        custom_target(
-                # XXX: workaround for old meson. Drop when upgrading.
-                'tmpfiles+' + file,
-                input : file + '.in',
-                output: file,
-                command : [meson_render_jinja2, config_h, '@INPUT@'],
-                capture : true,
-                install : enable_tmpfiles,
-                install_dir : tmpfilesdir)
+foreach pair : in_files
+        if not enable_tmpfiles
+                # do nothing
+        elif pair[1] == '' or conf.get(pair[1]) == 1
+                custom_target(
+                        # XXX: workaround for old meson. Drop when upgrading.
+                        'tmpfiles+' + pair[0],
+                        input : pair[0] + '.in',
+                        output: pair[0],
+                        command : [meson_render_jinja2, config_h, '@INPUT@'],
+                        capture : true,
+                        install : enable_tmpfiles,
+                        install_dir : tmpfilesdir)
+        else
+                message('Not installing tmpfiles.d/@0@ because @1@ is @2@'
+                        .format(pair[0], pair[1], conf.get(pair[1], 0)))
+        endif
 endforeach
 
 if enable_tmpfiles and install_sysconfdir