anaconda, lorax: drop rootfs.img inside squashfs

Package root filesystem directly as squashfs image. The most important
gain is getting rid of greatly unreproducible ext4 image creation. But
also it makes the output image slightly smaller, and the build faster.
Also, dmsquash-live dracut module is not needed anymore, which reduce
initramfs size.

anaconda/dracut/anaconda-lib.sh

@@ -101,13 +101,30 @@ anaconda_live_root_dir() {
     anaconda_mount_sysroot $img
 }
 
+anaconda_mount_root_squashfs() {
+    local img="$1"
+
+    ROOTFLAGS="$(getarg rootflags)"
+
+    modprobe squashfs || die "squashfs not supported"
+    modprobe overlay || die "overlayfs not supported"
+    mkdir -m 0755 -p /run/overlayfs
+    mkdir -m 0755 -p /run/rootfsbase
+    mkdir -m 0755 -p /run/ovlwork
+
+    mount -r "$img" /run/rootfsbase
+
+    printf 'mount -t overlay LiveOS_rootfs -o%s,%s %s\n' "$ROOTFLAGS" \
+        'lowerdir=/run/rootfsbase,upperdir=/run/overlayfs,workdir=/run/ovlwork' \
+        "$NEWROOT" > $hookdir/mount/01-$$-live.sh
+    # satisfy wait_for_dev /dev/root
+    ln -s /dev/null /dev/root
+}
+
 anaconda_mount_sysroot() {
     local img="$1"
     if [ -e "$img" ]; then
-        /sbin/dmsquash-live-root $img
-        # dracut & systemd only mount things with root=live: so we have to do this ourselves
-        # See https://bugzilla.redhat.com/show_bug.cgi?id=1232411
-        printf 'mount /dev/mapper/live-rw %s\n' "$NEWROOT" > $hookdir/mount/01-$$-anaconda.sh
+        anaconda_mount_root_squashfs "$img"
     fi
 }
 

anaconda/dracut/module-setup.sh

@@ -7,7 +7,7 @@ check() {
 }
 
 depends() {
-    echo img-lib dmsquash-live
+    echo img-lib
     case "$(uname -m)" in
         s390*) echo cms ;;
     esac

lorax/0005-Drop-inner-rootfs.img-layer.patch

@@ -0,0 +1,48 @@
+From cfc809df64e2778e51d47dc8b4466cf98efe8a2b Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
+ <marmarek@invisiblethingslab.com>
+Date: Wed, 3 Oct 2018 20:00:19 +0200
+Subject: [PATCH] Drop inner rootfs.img layer
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+Organization: Invisible Things Lab
+Cc: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
+
+Make runtime directly into squashfs image. This reduces largely
+unreproducible ext4 layer, but requires dracut module modification to
+properly mount the image.
+
+Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
+---
+ src/pylorax/treebuilder.py | 12 +++---------
+ 1 file changed, 3 insertions(+), 9 deletions(-)
+
+diff --git a/src/pylorax/treebuilder.py b/src/pylorax/treebuilder.py
+index 5d4f8b7..b804c2f 100644
+--- a/src/pylorax/treebuilder.py
++++ b/src/pylorax/treebuilder.py
+@@ -212,17 +212,11 @@ class RuntimeBuilder(object):
+             generate_module_info(moddir+kver, outfile=moddir+"module-info")
+ 
+     def create_runtime(self, outfile="/var/tmp/squashfs.img", compression="xz", compressargs=None, size=2):
+-        # make live rootfs image - must be named "LiveOS/rootfs.img" for dracut
+         compressargs = compressargs or []
+-        workdir = joinpaths(os.path.dirname(outfile), "runtime-workdir")
+-        os.makedirs(joinpaths(workdir, "LiveOS"))
++        os.makedirs(os.path.dirname(outfile))
+ 
+-        imgutils.mkrootfsimg(self.vars.root, joinpaths(workdir, "LiveOS/rootfs.img"),
+-                             "Anaconda", size=size)
+-
+-        # squash the live rootfs and clean up workdir
+-        imgutils.mksquashfs(workdir, outfile, compression, compressargs)
+-        remove(workdir)
++        # squash the rootfs
++        imgutils.mksquashfs(self.vars.root, outfile, compression, compressargs)
+ 
+     def finished(self):
+         """ Done using RuntimeBuilder
+-- 
+2.17.1
+

lorax/lorax.spec

@@ -20,6 +20,7 @@ Patch1:         0001-Allow-specify-gpg-key-for-a-repository.patch
 Patch2:         0002-verify-packages-signature.patch
 Patch3:         0003-Update-package-verification-for-dnf-API.patch
 Patch4:         0004-Remove-branding-code.patch
+Patch5:         0005-Drop-inner-rootfs.img-layer.patch
 
 BuildRequires:  python3-devel
 
@@ -126,6 +127,7 @@ Lorax templates for creating the boot.iso and live isos are placed in
 %patch2 -p1
 %patch3 -p1
 %patch4 -p1
+%patch5 -p1
 
 %build