[PATCH 3/5 v2] buildchroot: Enable isar-apt

[Alexander Smirnov <asmirnov@ilbers.de>]

This patch provides access to isar-apt from buildchroot. It does the
following:
 - mount isar-apt during buildchroot building.
 - umount isar-apt using bitbake events.

Also it needs to keep Isar build tree clean from any mounts despite on whether
build succeed of failed. bitbake provides various events that could trigger
custom python hooks. In this patch BuildCompleted event is used, which happened
when bitbake finished its execution despite on the result.

Signed-off-by: Alexander Smirnov <asmirnov@ilbers.de>
---
 meta-isar/conf/local.conf.sample                     |  3 +++
 meta/classes/isar-events.bbclass                     | 20 ++++++++++++++++++++
 meta/recipes-devtools/buildchroot/buildchroot.bb     | 10 ++++++++++
 .../buildchroot/files/multistrap.conf.in             |  8 +++++++-
 4 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 meta/classes/isar-events.bbclass

diff --git a/meta-isar/conf/local.conf.sample b/meta-isar/conf/local.conf.sample
index 2ae43e7..fc760ed 100644
--- a/meta-isar/conf/local.conf.sample
+++ b/meta-isar/conf/local.conf.sample
@@ -158,3 +158,6 @@ IMAGE_INSTALL = "example-hello example-raw"
 #
 # Default parallel jobs for bitbake:
 BB_NUMBER_THREADS = "4"
+
+# Add event handlers for bitbake
+INHERIT += "isar-events"
diff --git a/meta/classes/isar-events.bbclass b/meta/classes/isar-events.bbclass
new file mode 100644
index 0000000..55fc106
--- /dev/null
+++ b/meta/classes/isar-events.bbclass
@@ -0,0 +1,20 @@
+# Isar event handlers.
+#
+# This software is a part of ISAR.
+# Copyright (C) 2015-2017 ilbers GmbH
+
+addhandler isar_handler
+
+python isar_handler () {
+    import subprocess
+
+    devnull = open(os.devnull, 'w')
+
+    if isinstance(e, bb.event.BuildCompleted):
+        bchroot = d.getVar('BUILDCHROOT_DIR', True)
+
+        # Clean up buildchroot
+        subprocess.call('/usr/bin/sudo /bin/umount ' + bchroot + '/isar-apt || /bin/true', stdout=devnull, stderr=devnull, shell=True)
+
+    devnull.close()
+}
diff --git a/meta/recipes-devtools/buildchroot/buildchroot.bb b/meta/recipes-devtools/buildchroot/buildchroot.bb
index 51f9d5d..0044a71 100644
--- a/meta/recipes-devtools/buildchroot/buildchroot.bb
+++ b/meta/recipes-devtools/buildchroot/buildchroot.bb
@@ -31,8 +31,18 @@ BUILDCHROOT_PREINSTALL ?= "gcc \
 
 WORKDIR = "${TMPDIR}/work/${DISTRO}-${DISTRO_ARCH}/${PN}"
 
+do_prepare[nostamp] = "1"
+do_prepare[dirs] = "${BUILDCHROOT_DIR}/isar-apt"
+
+do_prepare() {
+    sudo mount --bind ${DEPLOY_DIR_APT}/${DISTRO} ${BUILDCHROOT_DIR}/isar-apt
+}
+
+addtask prepare before do_build after do_unpack
+
 do_build[stamp-extra-info] = "${DISTRO}-${DISTRO_ARCH}"
 do_build[dirs] = "${WORKDIR}/hooks_multistrap"
+do_build[depends] = "isar-apt:do_cache_config"
 
 do_build() {
     E="${@ bb.utils.export_proxies(d)}"
diff --git a/meta/recipes-devtools/buildchroot/files/multistrap.conf.in b/meta/recipes-devtools/buildchroot/files/multistrap.conf.in
index a0b28e3..480a4b8 100644
--- a/meta/recipes-devtools/buildchroot/files/multistrap.conf.in
+++ b/meta/recipes-devtools/buildchroot/files/multistrap.conf.in
@@ -6,7 +6,7 @@ noauth=true
 unpack=true
 ignorenativearch=true
 bootstrap=##DISTRO_MULTICONF_BOOTSTRAP##
-aptsources=##DISTRO_MULTICONF_APTSOURCES##
+aptsources=isar-apt ##DISTRO_MULTICONF_APTSOURCES##
 configscript=##CONFIG_SCRIPT##
 setupscript=##SETUP_SCRIPT##
 hookdir=##DIR_HOOKS##
@@ -29,3 +29,9 @@ source=##DISTRO_APT_SOURCE_SEC##
 suite=##DISTRO_SUITE##/updates
 components=##DISTRO_COMPONENTS##
 omitdebsrc=true
+
+[isar-apt]
+source=file:///isar-apt
+suite=isar
+components=main
+omitdebsrc=true
-- 
2.1.4