From b25d0337b8b97b70145fbde54d4ac4a5e07ca2a1 Mon Sep 17 00:00:00 2001
From: Ian Wienand <iwienand@redhat.com>
Date: Sun, 22 Oct 2017 16:16:04 +0000
Subject: [PATCH] Move to a common lock-file directory

In a couple of places we use flock for critical sections, but we leave
lockfiles around in various locations which can be confusing.

Introduce DIB_LOCKFILES global (under ~/.cache/dib/lockfiles) and
write lockfiles in there.

Fix up removal of the lockfile in the yum path; we just want to make
sure we cleanup the .rpmmacros file, but we don't need to remove the
lockfile as well.

Co-Authored-By: Andreas Florath <andreas@florath.net>

Change-Id: Ie810b2836be521325afe923708d046112e1e1e20
---
 .../elements/ubuntu-core/root.d/10-cache-ubuntu-image      | 2 +-
 .../elements/ubuntu/root.d/10-cache-ubuntu-tarball         | 2 +-
 .../elements/yum-minimal/root.d/08-yum-chroot              | 6 +++---
 diskimage_builder/lib/disk-image-create                    | 7 +++++++
 4 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/diskimage_builder/elements/ubuntu-core/root.d/10-cache-ubuntu-image b/diskimage_builder/elements/ubuntu-core/root.d/10-cache-ubuntu-image
index cd00ca2a9..9f16abfd6 100755
--- a/diskimage_builder/elements/ubuntu-core/root.d/10-cache-ubuntu-image
+++ b/diskimage_builder/elements/ubuntu-core/root.d/10-cache-ubuntu-image
@@ -29,7 +29,7 @@ DIB_CLOUD_IMAGES=${DIB_CLOUD_IMAGES:-http://cdimage.ubuntu.com/ubuntu-core/relea
 BASE_IMAGE_FILE=${BASE_IMAGE_FILE:-ubuntu-core-$numeric_release-core-$ARCH.tar.gz}
 SHA256SUMS=${SHA256SUMS:-$DIB_CLOUD_IMAGES/SHA256SUMS}
 CACHED_FILE=$DIB_IMAGE_CACHE/$BASE_IMAGE_FILE
-CACHED_FILE_LOCK=$DIB_IMAGE_CACHE/$BASE_IMAGE_FILE.lock
+CACHED_FILE_LOCK=$DIB_LOCKFILES/$BASE_IMAGE_FILE.lock
 CACHED_SUMS=$DIB_IMAGE_CACHE/SHA256SUMS.ubuntu-core.$DIB_RELEASE.$ARCH
 
 function get_ubuntu_tarball() {
diff --git a/diskimage_builder/elements/ubuntu/root.d/10-cache-ubuntu-tarball b/diskimage_builder/elements/ubuntu/root.d/10-cache-ubuntu-tarball
index a6ece7680..41241a5b5 100755
--- a/diskimage_builder/elements/ubuntu/root.d/10-cache-ubuntu-tarball
+++ b/diskimage_builder/elements/ubuntu/root.d/10-cache-ubuntu-tarball
@@ -17,7 +17,7 @@ DIB_RELEASE=${DIB_RELEASE:-trusty}
 BASE_IMAGE_FILE=${BASE_IMAGE_FILE:-$DIB_RELEASE-server-cloudimg-$ARCH-root.tar.gz}
 SHA256SUMS=${SHA256SUMS:-https://${DIB_CLOUD_IMAGES##http?(s)://}/$DIB_RELEASE/current/SHA256SUMS}
 CACHED_FILE=$DIB_IMAGE_CACHE/$BASE_IMAGE_FILE
-CACHED_FILE_LOCK=$DIB_IMAGE_CACHE/$BASE_IMAGE_FILE.lock
+CACHED_FILE_LOCK=$DIB_LOCKFILES/$BASE_IMAGE_FILE.lock
 CACHED_SUMS=$DIB_IMAGE_CACHE/SHA256SUMS.ubuntu.$DIB_RELEASE.$ARCH
 
 function get_ubuntu_tarball() {
diff --git a/diskimage_builder/elements/yum-minimal/root.d/08-yum-chroot b/diskimage_builder/elements/yum-minimal/root.d/08-yum-chroot
index 0e5291e56..c69aa7a4f 100755
--- a/diskimage_builder/elements/yum-minimal/root.d/08-yum-chroot
+++ b/diskimage_builder/elements/yum-minimal/root.d/08-yum-chroot
@@ -201,14 +201,14 @@ function _install_pkg_manager {
             --installroot $TARGET_ROOT \
             install $@ ${_lang_pack} ${_extra_pkgs} && rc=$? || rc=$?
 
-        # We modified the base system - make sure we clean up always!
-        rm $HOME/.rpmmacros.dib.lock
+        # Note we've modified the base system's .rpmmacros.  Ensure we
+        # clean it up *always*
         # sed makes it easy to remove last line, but not last n lines...
         sed -i '$ d' $HOME/.rpmmacros; sed -i '$ d' $HOME/.rpmmacros;
         if [ $rc != 0 ]; then
             die "Initial yum install to chroot failed!  Can not continue."
         fi
-    ) 9>$HOME/.rpmmacros.dib.lock
+    ) 9>$DIB_LOCKFILES/.rpmmacros.dib.lock
 
     # Set gpg path back because subsequent actions will take place in
     # the chroot
diff --git a/diskimage_builder/lib/disk-image-create b/diskimage_builder/lib/disk-image-create
index 70b1db7aa..24eb62ddf 100644
--- a/diskimage_builder/lib/disk-image-create
+++ b/diskimage_builder/lib/disk-image-create
@@ -166,9 +166,16 @@ done
 
 export DIB_DEBUG_TRACE
 
+# TODO: namespace this under ~/.cache/dib/ for consistency
 export DIB_IMAGE_CACHE=${DIB_IMAGE_CACHE:-~/.cache/image-create}
 mkdir -p $DIB_IMAGE_CACHE
 
+# We have a couple of critical sections (touching parts of the host
+# system or download images to common cache) that we use flock around.
+# Use this directory for lockfiles.
+export DIB_LOCKFILES=${DIB_LOCKFILES:-~/.cache/dib/lockfiles}
+mkdir -p $DIB_LOCKFILES
+
 if [ "$CLEAR_ENV" = "1" -a "$HOME" != "" ]; then
   echo "Re-execing to clear environment."
   echo "(note this will prevent much of the local_config element from working)"