Add kdump dracut config

In some cases, customizing the first kernel's initrd is necessary by
modifying the dracut `omit_dracutmodules` options, such as in Bootc
or CoreOS scenarios [1]. However, these changes can unintentionally
break existing functionality in kdump. For instance, setting
`omit_dracutmodules='nfs'` prevents the `nfs` module from being added.

Additionally, some dracut configurations [2] use
`dracutmodules+='some modules'` instead of
`add_dracutmodules+='some modules'`. When `dracutmodules` is non-empty,
dracut includes only the specified modules, which can result in an
initrd that lacks necessary modules, causing kdump to fail.

Dracut upstream support --add-confdir now, kdump can use this
option when building kdump initramfs.

This patch moved the hardcoded dracutmodules from mkdumprd to the new
conf file /lib/kdump/dracut.conf.d/99-kdump.conf, it is easier to check
and modify to omit or add certain modules. This patch also initialize
dracutmodules to empty to avoid the influence of other configurations.

See also:
[1] rhkdump#11
[2] https://issues.redhat.com/browse/RHEL-49590?focusedId=25197134&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-25197134

Suggested-by: Dave Young <[email protected]>
Suggested-by: Colin Walters <[email protected]>
Signed-off-by: Lichen Liu <[email protected]>

99-kdump.conf

@@ -0,0 +1,3 @@
+dracutmodules=''
+add_dracutmodules=' kdumpbase '
+omit_dracutmodules=' rdma plymouth resume ifcfg earlykdump '

Makefile

@@ -33,7 +33,7 @@ manpages:
 	install -D -m 644 kdump.conf.5 $(DESTDIR)$(mandir)/man5/kdump.conf.5
 
 install: dracut-modules kdump-conf kdump-sysconfig manpages
-	mkdir -p $(DESTDIR)$(pkglibdir)
+	mkdir -p $(DESTDIR)$(pkglibdir)/dracut.conf.d
 	mkdir -p -m755 $(DESTDIR)$(sysconfdir)/kdump/pre.d
 	mkdir -p -m755 $(DESTDIR)$(sysconfdir)/kdump/post.d
 	mkdir -p -m755 $(DESTDIR)$(localstatedir)/crash
@@ -46,6 +46,7 @@ install: dracut-modules kdump-conf kdump-sysconfig manpages
 	install -D -m 644 kdump.conf $(DESTDIR)$(sysconfdir)
 	install -D -m 644 kdump.sysconfig $(DESTDIR)$(sysconfdir)/sysconfig/kdump
 	install -D -m 755 kdump-lib.sh kdump-lib-initramfs.sh kdump-logger.sh -t $(DESTDIR)$(pkglibdir)
+	install -D -m 644 99-kdump.conf -t $(DESTDIR)$(pkglibdir)/dracut.conf.d
 
 ifeq ($(ARCH), $(filter ppc64le ppc64,$(ARCH)))
 	install -m 755 mkfadumprd $(DESTDIR)$(sbindir)

mkdumprd

@@ -29,15 +29,13 @@ SSH_KEY_LOCATION=$DEFAULT_SSHKEY
 SAVE_PATH=$(get_save_path)
 
 declare -a dracut_args
-dracut_args+=(--add kdumpbase)
 dracut_args+=(--quiet)
 dracut_args+=(--hostonly)
 dracut_args+=(--hostonly-cmdline)
 dracut_args+=(--hostonly-i18n)
 dracut_args+=(--hostonly-mode strict)
 dracut_args+=(--hostonly-nics '')
 dracut_args+=(--aggressive-strip)
-dracut_args+=(--omit "rdma plymouth resume ifcfg earlykdump")
 
 MKDUMPRD_TMPDIR="$(mktemp -d -t mkdumprd.XXXXXX)"
 [ -d "$MKDUMPRD_TMPDIR" ] || perror_exit "dracut: mktemp -p -d -t dracut.XXXXXX failed."
@@ -441,4 +439,13 @@ elif ! is_fadump_capable && \
 	add_mount "$status_target"
 fi
 
+# Use kdump managed dracut profile.
+[[ $kdump_dracut_confdir ]] || kdump_dracut_confdir=/lib/kdump/dracut.conf.d
+if [[ "$(dracut --help)" == *--add-confdir* ]] && [[ -d "$kdump_dracut_confdir" ]]; then
+	dracut_args+=("--add-confdir" "$kdump_dracut_confdir")
+else
+	dracut_args+=(--add kdumpbase)
+	dracut_args+=(--omit "rdma plymouth resume ifcfg earlykdump")
+fi
+
 dracut "${dracut_args[@]}" "$@"