classes/buildhistory: track contents of selected files in images

Add a BUILDHISTORY_IMAGE_FILES variable specifying a space-separated
list of files within an image to copy into buildhistory, so that changes
to them can be tracked. Typically this would be used for configuration
files, and by default this includes /etc/passwd and /etc/group, but the
user is free to extend this list by setting the variable in local.conf.

Implements [YOCTO #4154].

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 27 insertions, 6 deletions

diff --git a/meta/classes/buildhistory.bbclass b/meta/classes/buildhistory.bbclass
index 8efd41cd8e..3b6ce99413 100644
--- a/meta/classes/buildhistory.bbclass
+++ b/meta/classes/buildhistory.bbclass
@@ -12,6 +12,7 @@ BUILDHISTORY_DIR ?= "${TOPDIR}/buildhistory"
 BUILDHISTORY_DIR_IMAGE = "${BUILDHISTORY_DIR}/images/${MACHINE_ARCH}/${TCLIBC}/${IMAGE_BASENAME}"
 BUILDHISTORY_DIR_PACKAGE = "${BUILDHISTORY_DIR}/packages/${MULTIMACH_TARGET_SYS}/${PN}"
 BUILDHISTORY_DIR_SDK = "${BUILDHISTORY_DIR}/sdk/${SDK_NAME}"
+BUILDHISTORY_IMAGE_FILES ?= "/etc/passwd /etc/group"
 BUILDHISTORY_COMMIT ?= "0"
 BUILDHISTORY_COMMIT_AUTHOR ?= "buildhistory <buildhistory@${DISTRO}>"
 BUILDHISTORY_PUSH_REPO ?= ""
@@ -396,6 +397,15 @@ buildhistory_get_imageinfo() {
 
 	buildhistory_list_files ${IMAGE_ROOTFS} ${BUILDHISTORY_DIR_IMAGE}/files-in-image.txt
 
+	# Collect files requested in BUILDHISTORY_IMAGE_FILES
+	rm -rf ${BUILDHISTORY_DIR_IMAGE}/image-files
+	for f in ${BUILDHISTORY_IMAGE_FILES}; do
+		if [ -f ${IMAGE_ROOTFS}/$f ] ; then
+			mkdir -p ${BUILDHISTORY_DIR_IMAGE}/image-files/`dirname $f`
+			cp ${IMAGE_ROOTFS}/$f ${BUILDHISTORY_DIR_IMAGE}/image-files/$f
+		fi
+	done
+
 	# Record some machine-readable meta-information about the image
 	printf ""  > ${BUILDHISTORY_DIR_IMAGE}/image-info.txt
 	cat >> ${BUILDHISTORY_DIR_IMAGE}/image-info.txt <<END
diff --git a/meta/lib/oe/buildhistory_analysis.py b/meta/lib/oe/buildhistory_analysis.py
index 2306bcb4bf..86b5a12347 100644
--- a/meta/lib/oe/buildhistory_analysis.py
+++ b/meta/lib/oe/buildhistory_analysis.py
@@ -52,7 +52,10 @@ class ChangeRecord:
 
     def _str_internal(self, outer):
         if outer:
-            prefix = '%s: ' % self.path
+            if '/image-files/' in self.path:
+                prefix = '%s: ' % self.path.split('/image-files/')[0]
+            else:
+                prefix = '%s: ' % self.path
         else:
             prefix = ''
 
@@ -107,16 +110,21 @@ class ChangeRecord:
             diff = difflib.unified_diff(alines, blines, self.fieldname, self.fieldname, lineterm='')
             out += '\n  '.join(list(diff)[2:])
             out += '\n  --'
-        elif self.fieldname in img_monitor_files:
-            if outer:
-                prefix = 'Changes to %s ' % self.path
-            out = '(%s):\n  ' % self.fieldname
+        elif self.fieldname in img_monitor_files or '/image-files/' in self.path:
+            fieldname = self.fieldname
+            if '/image-files/' in self.path:
+                fieldname = os.path.join('/' + self.path.split('/image-files/')[1], self.fieldname)
+                out = 'Changes to %s:\n  ' % fieldname
+            else:
+                if outer:
+                    prefix = 'Changes to %s ' % self.path
+                out = '(%s):\n  ' % self.fieldname
             if self.filechanges:
                 out += '\n  '.join(['%s' % i for i in self.filechanges])
             else:
                 alines = self.oldvalue.splitlines()
                 blines = self.newvalue.splitlines()
-                diff = difflib.unified_diff(alines, blines, self.fieldname, self.fieldname, lineterm='')
+                diff = difflib.unified_diff(alines, blines, fieldname, fieldname, lineterm='')
                 out += '\n  '.join(list(diff))
                 out += '\n  --'
         else:
@@ -393,6 +401,9 @@ def process_changes(repopath, revision1, revision2 = 'HEAD', report_all = False)
                     changes.append(chg)
             elif filename == 'image-info.txt':
                 changes.extend(compare_dict_blobs(path, d.a_blob, d.b_blob, report_all))
+            elif '/image-files/' in path:
+                chg = ChangeRecord(path, filename, d.a_blob.data_stream.read(), d.b_blob.data_stream.read(), True)
+                changes.append(chg)
 
     # Look for added preinst/postinst/prerm/postrm
     # (without reporting newly added recipes)