From 629137379447e95834bc11ada6549c8f553d9666 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] Add --squashfs-only option to drop inner rootfs.img layer

Make runtime directly into squashfs image. This reduces largely
unreproducible ext4 layer, but requires anaconda's dracut module
modification to properly mount the image.

(cherry picked from commit 27e611629f2c654939b0894086512e9d4f366113)
Signed-off-by: Brian C. Lane <bcl@redhat.com>

Resolves: rhbz#1846282
---
 src/pylorax/__init__.py    | 16 ++++++++++++----
 src/pylorax/cmdline.py     |  2 ++
 src/pylorax/creator.py     |  2 +-
 src/pylorax/treebuilder.py | 11 ++++++++++-
 src/sbin/lorax             |  3 ++-
 5 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/pylorax/__init__.py b/src/pylorax/__init__.py
index 2ccfb950..0ed470a4 100644
--- a/src/pylorax/__init__.py
+++ b/src/pylorax/__init__.py
@@ -187,7 +187,8 @@ class Lorax(BaseLoraxClass):
             add_arch_template_vars=None,
             verify=True,
             user_dracut_args=None,
-            skip_branding=False):
+            skip_branding=False,
+            squashfs_only=False):
 
         assert self._configured
 
@@ -320,9 +321,16 @@ class Lorax(BaseLoraxClass):
                 compressargs += ["-Xbcj", self.arch.bcj]
             else:
                 logger.info("no BCJ filter for arch %s", self.arch.basearch)
-        rb.create_runtime(joinpaths(installroot,runtime),
-                          compression=compression, compressargs=compressargs,
-                          size=size)
+        if squashfs_only:
+            # Create an ext4 rootfs.img and compress it with squashfs
+            rb.create_squashfs_runtime(joinpaths(installroot,runtime),
+                compression=compression, compressargs=compressargs,
+                size=size)
+        else:
+            # Create an ext4 rootfs.img and compress it with squashfs
+            rb.create_ext4_runtime(joinpaths(installroot,runtime),
+                compression=compression, compressargs=compressargs,
+                size=size)
         rb.finished()
 
         logger.info("preparing to build output tree and boot images")
diff --git a/src/pylorax/cmdline.py b/src/pylorax/cmdline.py
index 869fc150..565b82bd 100644
--- a/src/pylorax/cmdline.py
+++ b/src/pylorax/cmdline.py
@@ -109,6 +109,8 @@ def lorax_parser(dracut_default=""):
                           help="Do not verify SSL certificates")
     optional.add_argument("--skip-branding", action="store_true", default=False,
                           help="Disable automatic branding package selection. Use --installpkgs to add custom branding.")
+    optional.add_argument("--squashfs-only", action="store_true", default=False,
+                          help="Use a plain squashfs filesystem for the runtime.")
 
     # dracut arguments
     dracut_group = parser.add_argument_group("dracut arguments")
diff --git a/src/pylorax/creator.py b/src/pylorax/creator.py
index 8b085417..c004f34a 100644
--- a/src/pylorax/creator.py
+++ b/src/pylorax/creator.py
@@ -203,7 +203,7 @@ def make_runtime(opts, mount_dir, work_dir, size=None):
     rb = RuntimeBuilder(product, arch, fake_dbo)
     compression, compressargs = squashfs_args(opts)
     log.info("Creating runtime")
-    rb.create_runtime(joinpaths(work_dir, RUNTIME), size=size,
+    rb.create_ext4_runtime(joinpaths(work_dir, RUNTIME), size=size,
                       compression=compression, compressargs=compressargs)
 
 
diff --git a/src/pylorax/treebuilder.py b/src/pylorax/treebuilder.py
index 19e39cfb..5547118c 100644
--- a/src/pylorax/treebuilder.py
+++ b/src/pylorax/treebuilder.py
@@ -229,7 +229,16 @@ class RuntimeBuilder(object):
             runcmd(["depmod", "-a", "-F", ksyms, "-b", root, kernel.version])
             generate_module_info(moddir+kernel.version, outfile=moddir+"module-info")
 
-    def create_runtime(self, outfile="/var/tmp/squashfs.img", compression="xz", compressargs=None, size=2):
+    def create_squashfs_runtime(self, outfile="/var/tmp/squashfs.img", compression="xz", compressargs=None, size=2):
+        """Create a plain squashfs runtime"""
+        compressargs = compressargs or []
+        os.makedirs(os.path.dirname(outfile))
+
+        # squash the rootfs
+        imgutils.mksquashfs(self.vars.root, outfile, compression, compressargs)
+
+    def create_ext4_runtime(self, outfile="/var/tmp/squashfs.img", compression="xz", compressargs=None, size=2):
+        """Create a squashfs compressed ext4 runtime"""
         # make live rootfs image - must be named "LiveOS/rootfs.img" for dracut
         compressargs = compressargs or []
         workdir = joinpaths(os.path.dirname(outfile), "runtime-workdir")
diff --git a/src/sbin/lorax b/src/sbin/lorax
index 3ae174fd..bb81e853 100755
--- a/src/sbin/lorax
+++ b/src/sbin/lorax
@@ -193,7 +193,8 @@ def main():
               add_arch_template_vars=parsed_add_arch_template_vars,
               remove_temp=True, verify=opts.verify,
               user_dracut_args=opts.dracut_args,
-              skip_branding=opts.skip_branding)
+              skip_branding=opts.skip_branding,
+              squashfs_only=opts.squashfs_only)
 
     # Release the lock on the tempdir
     os.close(dir_fd)