mkosi: Introduce build image

We want the exitrd image to be built with the latest systemd as well.
As the exitrd image is built as part of mkosi.images, and all subimages
are built before the main image, this implies the packages must be built
as a subimage in mkosi.images/ as well. So we introduce the build image and
move all logic related to building distribution packages there.

This also has the nice side effect of slimming down the main image as the
build dependencies are not installed into the main image anymore. It also
makes sure the packages are built in a "clean" chroot without any of the
other packages which we install in the main image available.

7 files changed, 19 insertions, 4 deletions

diff --git a/mkosi.images/exitrd/mkosi.conf b/mkosi.images/exitrd/mkosi.conf
index 3b25091759..28da8a592b 100644
--- a/mkosi.images/exitrd/mkosi.conf
+++ b/mkosi.images/exitrd/mkosi.conf
@@ -12,3 +12,6 @@ MakeInitrd=yes
 
 Packages=
         bash
+
+[Config]
+Include=%D/mkosi.sanitizers
diff --git a/mkosi.images/exitrd/mkosi.conf.d/10-arch.conf b/mkosi.images/exitrd/mkosi.conf.d/10-arch.conf
index c8b1904f6f..a5a6506e94 100644
--- a/mkosi.images/exitrd/mkosi.conf.d/10-arch.conf
+++ b/mkosi.images/exitrd/mkosi.conf.d/10-arch.conf
@@ -4,7 +4,7 @@
 Distribution=arch
 
 [Content]
-Packages=
+VolatilePackages=
         systemd
 
 RemoveFiles=
diff --git a/mkosi.images/exitrd/mkosi.conf.d/10-centos-fedora.conf b/mkosi.images/exitrd/mkosi.conf.d/10-centos-fedora.conf
index 8458dee37e..a1fa32b786 100644
--- a/mkosi.images/exitrd/mkosi.conf.d/10-centos-fedora.conf
+++ b/mkosi.images/exitrd/mkosi.conf.d/10-centos-fedora.conf
@@ -5,5 +5,5 @@ Distribution=|centos
 Distribution=|fedora
 
 [Content]
-Packages=
+VolatilePackages=
         systemd-standalone-shutdown
diff --git a/mkosi.images/exitrd/mkosi.conf.d/10-debian.conf b/mkosi.images/exitrd/mkosi.conf.d/10-debian.conf
index 68b0aa5fe7..6ca310cbc2 100644
--- a/mkosi.images/exitrd/mkosi.conf.d/10-debian.conf
+++ b/mkosi.images/exitrd/mkosi.conf.d/10-debian.conf
@@ -4,5 +4,5 @@
 Distribution=debian
 
 [Content]
-Packages=
+VolatilePackages=
         systemd-standalone-shutdown
diff --git a/mkosi.images/exitrd/mkosi.conf.d/10-opensuse.conf b/mkosi.images/exitrd/mkosi.conf.d/10-opensuse.conf
index 3f6df21f84..fb0a498df5 100644
--- a/mkosi.images/exitrd/mkosi.conf.d/10-opensuse.conf
+++ b/mkosi.images/exitrd/mkosi.conf.d/10-opensuse.conf
@@ -5,4 +5,7 @@ Distribution=opensuse
 
 [Content]
 Packages=
+        patterns-base-minimal_base
+
+VolatilePackages=
         systemd
diff --git a/mkosi.images/exitrd/mkosi.conf.d/10-ubuntu.conf b/mkosi.images/exitrd/mkosi.conf.d/10-ubuntu.conf
index ddd68dc1b4..61fe6baee0 100644
--- a/mkosi.images/exitrd/mkosi.conf.d/10-ubuntu.conf
+++ b/mkosi.images/exitrd/mkosi.conf.d/10-ubuntu.conf
@@ -4,5 +4,5 @@
 Distribution=ubuntu
 
 [Content]
-Packages=
+VolatilePackages=
         systemd
diff --git a/mkosi.images/exitrd/mkosi.conf.d/20-build.conf b/mkosi.images/exitrd/mkosi.conf.d/20-build.conf
new file mode 100644
index 0000000000..8c16d9b9f8
--- /dev/null
+++ b/mkosi.images/exitrd/mkosi.conf.d/20-build.conf
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+# Add a dependency on the build image unless NO_BUILD=1.
+
+[Match]
+Environment=!NO_BUILD=1
+
+[Config]
+Dependencies=build