Merge pull request #33761 from DaanDeMeyer/mkosi

mkosi: Various NO_BUILD improvements

docs/HACKING.md

@@ -44,6 +44,24 @@ or:
 $ mkosi qemu
 ```
 
+By default, the tools from your host system are used to build the image. To have
+`mkosi` use the systemd tools from the `build/` directory, add the following to
+`mkosi.local.conf`:
+
+```conf
+[Host]
+ExtraSearchPaths=build/
+```
+
+And if you want `mkosi` to build a tools image and use the tools from there
+instead of looking for tools on the host, add the following to
+`mkosi.local.conf`:
+
+```conf
+[Host]
+ToolsTree=default
+```
+
 Every time you rerun the `mkosi` command a fresh image is built, incorporating
 all current changes you made to the project tree. To avoid having to build a new
 image all the time when iterating on a patch, add the following to

meson.build

@@ -2673,6 +2673,7 @@ if mkosi.found()
                         '--output-dir', meson.current_build_dir() / 'mkosi.output',
                         '--cache-dir', meson.current_build_dir() / 'mkosi.cache',
                         '--build-dir', meson.current_build_dir() / 'mkosi.builddir',
+                        '--extra-search-path', meson.current_build_dir(),
                         '--force',
                         'build',
                 ],

mkosi.conf.d/10-centos/mkosi.conf

@@ -4,7 +4,7 @@
 Distribution=centos
 
 [Distribution]
-Release=9
+Release=10
 
 [Content]
 Environment=

mkosi.conf.d/10-extra-search-paths.conf

@@ -1,7 +0,0 @@
-# SPDX-License-Identifier: LGPL-2.1-or-later
-
-[Match]
-PathExists=build/
-
-[Host]
-ExtraSearchPaths=build/

mkosi.conf.d/10-tools.conf

@@ -1,8 +0,0 @@
-# SPDX-License-Identifier: LGPL-2.1-or-later
-
-[Match]
-PathExists=!build/
-SystemdVersion=<254
-
-[Host]
-@ToolsTree=default

mkosi.images/build/mkosi.sync

@@ -3,7 +3,7 @@
 set -e
 set -o nounset
 
-if ((${NO_SYNC:-0})); then
+if ((${NO_SYNC:-0})) || ((${NO_BUILD:-0})); then
     exit 0
 fi
 

test/README.testsuite

@@ -14,12 +14,41 @@ We also need to make sure the required meson options are enabled:
 $ meson setup --reconfigure build -Dremote=enabled
 ```
 
-Next, we can build the integration test image:
+To make sure `mkosi` doesn't try to build systemd from source during the image build
+process, you can add the following to `mkosi.local.conf`:
+
+```
+[Content]
+Environment=NO_BUILD=1
+```
+
+You might also want to use the `PackageDirectories=` or `Repositories=` option to provide
+mkosi with a directory or repository containing the systemd packages that should be installed
+instead. If the repository containing the systemd packages is not a builtin repository known
+by mkosi, you can use the `PackageManagerTrees=` option to write an extra repository definition
+to /etc which is used when building the image instead.
+
+Next, we can build the integration test image with meson:
 
 ```shell
 $ meson compile -C build mkosi
 ```
 
+By default, the `mkosi` meson target which builds the integration test image depends on
+other meson targets to build various systemd tools that are used to build the image to make
+sure they are up-to-date. If you instead want the already installed systemd tools on the
+host to be used, you can run `mkosi` manually to build the image. To build the integration test
+image without meson, run the following:
+
+```shell
+$ mkosi -f
+```
+
+Note that by default we assume that `build/` is used as the meson build directory that will be used to run
+the integration tests. If you want to use another directory as the meson build directory, you will have to
+configure the mkosi build directory (`BuildDirectory=`), cache directory (`CacheDirectory=`) and output
+directory (`OutputDirectory=`) to point to the other directory using `mkosi.local.conf`.
+
 After the image has been built, the integration tests can be run with:
 
 ```shell