sysext: new tool for managing "system extensions" for /usr/ + /opt/

meson.build

@@ -1502,6 +1502,7 @@ foreach term : ['analyze',
                 'nss-myhostname',
                 'nss-systemd',
                 'portabled',
+                'sysext',
                 'pstore',
                 'quotacheck',
                 'randomseed',
@@ -1745,6 +1746,7 @@ subdir('src/portable')
 subdir('src/pstore')
 subdir('src/resolve')
 subdir('src/shutdown')
+subdir('src/sysext')
 subdir('src/systemctl')
 subdir('src/timedate')
 subdir('src/timesync')
@@ -2202,6 +2204,17 @@ if conf.get('ENABLE_PORTABLED') == 1
                 install_dir : rootbindir)
 endif
 
+if conf.get('ENABLE_SYSEXT') == 1
+        public_programs += executable(
+                'systemd-sysext',
+                systemd_sysext_sources,
+                include_directories : includes,
+                link_with : [libshared],
+                install_rpath : rootlibexecdir,
+                install : true,
+                install_dir : rootbindir)
+endif
+
 if conf.get('ENABLE_USERDB') == 1
         executable(
                 'systemd-userwork',
@@ -3735,6 +3748,7 @@ foreach tuple : [
         ['logind'],
         ['machined'],
         ['portabled'],
+        ['sysext'],
         ['userdb'],
         ['homed'],
         ['importd'],

meson_options.txt

@@ -111,6 +111,8 @@ option('machined', type : 'boolean',
        description : 'install the systemd-machined stack')
 option('portabled', type : 'boolean',
        description : 'install the systemd-portabled stack')
+option('sysext', type : 'boolean',
+       description : 'install the systemd-sysext stack')
 option('userdb', type : 'boolean',
        description : 'install the systemd-userdbd stack')
 option('homed', type : 'combo', choices : ['auto', 'true', 'false'],

src/shared/machine-image.c

@@ -54,6 +54,12 @@ static const char* const image_search_path[_IMAGE_CLASS_MAX] = {
                             "/var/lib/portables\0"         /* the main place for images */
                             "/usr/local/lib/portables\0"
                             "/usr/lib/portables\0",
+
+        [IMAGE_EXTENSION] = "/etc/extensions\0"             /* only place symlinks here */
+                            "/run/extensions\0"             /* and here too */
+                            "/var/lib/extensions\0"         /* the main place for images */
+                            "/usr/local/lib/extensions\0"
+                            "/usr/lib/extensions\0",
 };
 
 static Image *image_free(Image *i) {

src/shared/machine-image.h

@@ -16,6 +16,7 @@
 typedef enum ImageClass {
         IMAGE_MACHINE,
         IMAGE_PORTABLE,
+        IMAGE_EXTENSION,
         _IMAGE_CLASS_MAX,
         _IMAGE_CLASS_INVALID = -1
 } ImageClass;

src/sysext/meson.build

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+systemd_sysext_sources = files('''
+        sysext.c
+'''.split())