From f64ffe85717f952877876cb0dea889237a03f22b Mon Sep 17 00:00:00 2001
From: Guohan Lu <gulv@microsoft.com>
Date: Sat, 2 Sep 2017 22:32:31 +0000
Subject: [PATCH] [baseimage]: build root filesystem via overlay fs instead of
 aufs

---
 build_debian.sh                      |  5 +++--
 files/initramfs-tools/modules        |  2 +-
 files/initramfs-tools/udev.patch     | 10 ++++++++++
 files/initramfs-tools/union-mount.j2 |  9 +++++----
 4 files changed, 19 insertions(+), 7 deletions(-)
 create mode 100644 files/initramfs-tools/udev.patch

diff --git a/build_debian.sh b/build_debian.sh
index 969ff9f07..c5c1d2305 100755
--- a/build_debian.sh
+++ b/build_debian.sh
@@ -116,7 +116,7 @@ sudo dpkg --root=$FILESYSTEM_ROOT -i target/debs/initramfs-tools_*.deb || \
 sudo dpkg --root=$FILESYSTEM_ROOT -i target/debs/linux-image-${LINUX_KERNEL_VERSION}-amd64_*.deb || \
     sudo LANG=C DEBIAN_FRONTEND=noninteractive chroot $FILESYSTEM_ROOT apt-get -y install -f
 
-## Update initramfs for booting with squashfs+aufs
+## Update initramfs for booting with squashfs+overlay
 cat files/initramfs-tools/modules | sudo tee -a $FILESYSTEM_ROOT/etc/initramfs-tools/modules > /dev/null
 
 ## Hook into initramfs: change fs type from vfat to ext4 on arista switches
@@ -148,6 +148,7 @@ sudo cp files/initramfs-tools/mgmt-intf-dhcp $FILESYSTEM_ROOT/etc/initramfs-tool
 sudo chmod +x $FILESYSTEM_ROOT/etc/initramfs-tools/scripts/init-bottom/mgmt-intf-dhcp
 sudo cp files/initramfs-tools/union-fsck $FILESYSTEM_ROOT/etc/initramfs-tools/hooks/union-fsck
 sudo chmod +x $FILESYSTEM_ROOT/etc/initramfs-tools/hooks/union-fsck
+pushd $FILESYSTEM_ROOT/usr/share/initramfs-tools/scripts/init-bottom && sudo patch -p1 < $OLDPWD/files/initramfs-tools/udev.patch; popd
 sudo chroot $FILESYSTEM_ROOT update-initramfs -u
 
 ## Install latest intel igb driver
@@ -273,7 +274,7 @@ sudo sed -i '
     ' $FILESYSTEM_ROOT/etc/monit/monitrc
 
 sudo tee -a $FILESYSTEM_ROOT/etc/monit/monitrc > /dev/null <<'EOF'
-check filesystem root-aufs with path /
+check filesystem root-overlay with path /
   if space usage > 90% for 5 times within 10 cycles then alert
 check filesystem var-log with path /var/log
   if space usage > 90% for 5 times within 10 cycles then alert
diff --git a/files/initramfs-tools/modules b/files/initramfs-tools/modules
index 1bd0eab15..33f28b98b 100644
--- a/files/initramfs-tools/modules
+++ b/files/initramfs-tools/modules
@@ -1,5 +1,5 @@
 squashfs
-aufs
+overlay
 vfat
 nls_cp437
 nls_utf8
diff --git a/files/initramfs-tools/udev.patch b/files/initramfs-tools/udev.patch
new file mode 100644
index 000000000..38c43dc27
--- /dev/null
+++ b/files/initramfs-tools/udev.patch
@@ -0,0 +1,10 @@
+--- a/udev	2017-09-02 23:13:45.078773236 +0000
++++ b/udev	2017-09-02 22:40:08.502773236 +0000
+@@ -1,6 +1,6 @@
+ #!/bin/sh -e
+
+-PREREQS=""
++PREREQS="union-mount"
+
+ prereqs() { echo "$PREREQS"; }
+
diff --git a/files/initramfs-tools/union-mount.j2 b/files/initramfs-tools/union-mount.j2
index db40d4f08..6369b8449 100644
--- a/files/initramfs-tools/union-mount.j2
+++ b/files/initramfs-tools/union-mount.j2
@@ -11,18 +11,19 @@ case $1 in
     ;;
 esac
 
-## Mount the aufs file system: rw layer over squashfs
+## Mount the overlay file system: rw layer over squashfs
 image_dir=$(cat /proc/cmdline | sed -e 's/.*loop=\(\S*\)\/.*/\1/')
 mkdir -p ${rootmnt}/host/$image_dir/rw
-mount -n -o dirs=${rootmnt}/host/$image_dir/rw:${rootmnt}=ro -t aufs root-aufs ${rootmnt}
+mkdir -p ${rootmnt}/host/$image_dir/work
+mount -n -o lowerdir=${rootmnt},upperdir=${rootmnt}/host/$image_dir/rw,workdir=${rootmnt}/host/$image_dir/work -t overlay root-overlay ${rootmnt}
 ## Check if the root block device is still there
 [ -b ${ROOT} ] || mdev -s
 ## Mount the raw partition again
 mount ${ROOT} ${rootmnt}/host
-## Mount the working directory of docker engine in the raw partition, bypass the aufs
+## Mount the working directory of docker engine in the raw partition, bypass the overlay
 mkdir -p ${rootmnt}/var/lib/docker
 mount --bind ${rootmnt}/host/$image_dir/{{ DOCKERFS_DIR }} ${rootmnt}/var/lib/docker
-## Mount the boot directory in the raw partition, bypass the aufs
+## Mount the boot directory in the raw partition, bypass the overlay
 mkdir -p ${rootmnt}/boot
 mount --bind ${rootmnt}/host/$image_dir/boot ${rootmnt}/boot
 ## Mount loop device for /var/log