Merge pull request #1698 from Vogtinator/check255

docs/distributor-notes.md

@@ -8,6 +8,10 @@ nav_order: 10
 1. TOC
 {:toc}
 
+## Dracut Module
+
+The distribution specific integration is responsible for ensuring that the ignition dracut module is included in the initramfs when necessary. This can be achieved by adding it as dependency of the dracut module containing the distribution integration, or by installing a dracut configuration file.
+
 ## Kernel Arguments
 
 When Ignition is updating kernel arguments it will call out to a binary (defined in `internal/distro/distro.go` and overridable at build-time via overriding the `github.com/coreos/ignition/v2/internal/distro.kargsCmd` build flag). Ignition expects that the binary accepts `--should-exist` & `--should-not-exist` parameters. Should exist operations should append the argument if missing and should not exist should NOT fail if the argument is not present. The binary should also reboot the system if necessary.

docs/release-notes.md

@@ -8,6 +8,9 @@ nav_order: 9
 
 ### Breaking changes
 
+- The dracut module is not automatically included in initramfs images anymore,
+  see distributor notes for details.
+
 ### Features
 
 ### Changes

dracut/30ignition/module-setup.sh

@@ -2,6 +2,13 @@
 # -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
 # ex: ts=8 sw=4 sts=4 et filetype=sh
 
+check() {
+    # Only include this if another module requests it.
+    # In our case it'll be the distro provided module with integration and customizations
+    # (coreos-ignition/ignition-microos/...).
+    return 255
+}
+
 depends() {
     echo qemu systemd url-lib network
 }