From 02b3b3b97766c46133ea89f8340459ccba12678a Mon Sep 17 00:00:00 2001
From: Julio Montes <julio.montes@intel.com>
Date: Thu, 16 May 2019 11:16:29 -0500
Subject: [PATCH] image-builder: remove unneeded systemd units and files

Remove systemd units and files that are not needed in Kata Containers.
Removing this files we can improve the boot time.

fixes #289

Signed-off-by: Julio Montes <julio.montes@intel.com>
---
 image-builder/Dockerfile       |  2 +-
 image-builder/image_builder.sh | 38 ++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/image-builder/Dockerfile b/image-builder/Dockerfile
index 0d1107ee7..457070f65 100644
--- a/image-builder/Dockerfile
+++ b/image-builder/Dockerfile
@@ -7,4 +7,4 @@ From fedora:latest
 
 RUN [ -n "$http_proxy" ] && sed -i '$ a proxy='$http_proxy /etc/dnf/dnf.conf ; true
 
-RUN dnf install -y qemu-img parted gdisk e2fsprogs gcc xfsprogs
+RUN dnf install -y qemu-img parted gdisk e2fsprogs gcc xfsprogs findutils
diff --git a/image-builder/image_builder.sh b/image-builder/image_builder.sh
index 44e15d6b7..fcb0eff14 100755
--- a/image-builder/image_builder.sh
+++ b/image-builder/image_builder.sh
@@ -34,6 +34,31 @@ readonly dax_header_sz=2
 # [2] - https://nvdimm.wiki.kernel.org/2mib_fs_dax
 readonly dax_alignment=2
 
+# The list of systemd units and files that are not needed in Kata Containers
+readonly -a systemd_units=(
+	"systemd-coredump@"
+	"systemd-journald"
+	"systemd-journald-dev-log"
+	"systemd-journal-flush"
+	"systemd-random-seed"
+	"systemd-timesyncd"
+	"systemd-tmpfiles-setup"
+	"systemd-udevd"
+	"systemd-udevd-control"
+	"systemd-udevd-kernel"
+	"systemd-udev-trigger"
+	"systemd-update-utmp"
+)
+
+readonly -a systemd_files=(
+	"systemd-bless-boot-generator"
+	"systemd-fstab-generator"
+	"systemd-getty-generator"
+	"systemd-gpt-auto-generator"
+	"systemd-tmpfiles-cleanup.timer"
+	"tmp.mount"
+)
+
 # Set a default value
 AGENT_INIT=${AGENT_INIT:-no}
 
@@ -344,6 +369,19 @@ create_rootfs_image() {
 	sync
 	OK "rootfs copied"
 
+	info "Removing unneeded systemd services and sockets"
+	for u in "${systemd_units[@]}"; do
+		find "${mount_dir}" -type f \( \
+			 -name "${u}.service" -o \
+			 -name "${u}.socket" \) \
+			 -exec rm -f {} \;
+	done
+
+	info "Removing unneeded systemd files"
+	for u in "${systemd_files[@]}"; do
+		find "${mount_dir}" -type f -name "${u}" -exec rm -f {} \;
+	done
+
 	info "Unmounting root partition"
 	umount "${mount_dir}"
 	OK "Root partition unmounted"