[PATCH] package_deb: create md5sums control files

[Michael Smith <msmith@cbnco.com>]

These are created with the package and get installed in
/var/dpkg/info. Afterward it's a great way to find modified files
for backup with a little shell script magic.

It feels a bit weird to still use MD5, but that seems to be the
convention in the Debian world.

Signed-off-by: Michael Smith <msmith@cbnco.com>
---
 classes/package.bbclass     |   45 +++++++++++++++++++++++++++++++++++++++++++
 classes/package_deb.bbclass |    7 ++++++
 2 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/classes/package.bbclass b/classes/package.bbclass
index f6bd7c5..e3f55b5 100644
--- a/classes/package.bbclass
+++ b/classes/package.bbclass
@@ -202,6 +202,51 @@ def runstrip(file, d):
 
     return 1
 
+def write_package_md5sums (root, outfile, ignorepaths):
+    # For each regular file under root, writes an md5sum to outfile.
+    # With thanks to patch.bbclass.
+    import bb, os
+
+    try:
+        # Python 2.5+
+        import hashlib
+        ctor = hashlib.md5
+    except ImportError:
+        import md5
+        ctor = md5.new
+
+    outf = file(outfile, 'w')
+
+    # Each output line looks like: "<hex...>  <filename without leading slash>"
+    striplen = len(root)
+    if not root.endswith('/'):
+        striplen += 1
+
+    for walkroot, dirs, files in os.walk(root):
+        # Skip e.g. the DEBIAN directory
+        if walkroot[striplen:] in ignorepaths:
+            dirs[:] = []
+            continue
+
+        for name in files:
+            fullpath = os.path.join(walkroot, name)
+            if os.path.islink(fullpath) or (not os.path.isfile(fullpath)):
+                continue
+
+            m = ctor()
+            f = file(fullpath, 'rb')
+            while True:
+                d = f.read(8192)
+                if not d:
+                    break
+                m.update(d)
+            f.close()
+
+            print >> outf, "%s  %s" % (m.hexdigest(), fullpath[striplen:])
+            
+    outf.close()
+
+
 #
 # Package data handling routines
 #
diff --git a/classes/package_deb.bbclass b/classes/package_deb.bbclass
index e5339a9..4a17010 100644
--- a/classes/package_deb.bbclass
+++ b/classes/package_deb.bbclass
@@ -243,6 +243,13 @@ python do_package_deb () {
                 conffiles.write('%s\n' % f)
             conffiles.close()
 
+        try:
+            write_package_md5sums(root, os.path.join(controldir, 'md5sums'),
+                                  ['DEBIAN'])
+        except:
+            bb.utils.unlockfile(lf)
+            raise
+
         os.chdir(basedir)
         ret = os.system("PATH=\"%s\" fakeroot dpkg-deb -b %s %s" % (bb.data.getVar("PATH", localdata, 1), root, pkgoutdir))
         if ret != 0:
-- 
1.6.3