Merge lp:~allenap/maas/simplestreams-moved-checksummer-back--1.8 into lp:maas/1.8

[Gavin Panella]

Backport r4351 from trunk: Find checksummer in simplestreams.util only.

The checksummer name has been republished in simplestreams.util, and the upstream has advised us to find it only there.

Scott has put the checksummer object back into simplestreams.util and advised us to revert our earlier change to find it in simplestreams.checksum_util. This is the backport to 1.8.

[Mike Pontillo (mpontillo)]

Do we know which versions of simplestreams support this? Are we certain that a compliant version of simplestreams already available in our 1.8 PPAs? (or been accepted as a SRU?) Also, is there a [simplestreams] bug we should link this branch to?

review: Needs Information

[Mike Pontillo (mpontillo)]

Actually even if it's an SRU, we need to ensure it's in the PPA. (because the user may not have enabled -updates).

Do we need a corresponding packaging change here with a version restriction for simplestreams? Or should we keep the try/except style detection code?

[Blake Rouse (blake-rouse)]

review: Approve

[Gavin Panella (allenap)]

The version of simplestreams released with the breakage was very soon superseded by a fix released via security, and we don't support Ubuntu with security updates disabled. In other words, I think we're fine.

[Mike Pontillo (mpontillo)]

OK, sounds good then.

review: Approve

=== modified file 'src/maasserver/bootresources.py'
--- src/maasserver/bootresources.py	2015-09-25 14:38:46 +0000
+++ src/maasserver/bootresources.py	2015-10-06 17:18:33 +0000
@@ -98,12 +98,6 @@
 from twisted.python import log
 
 
-try:
-    from simplestreams.checksum_util import checksummer
-except ImportError:
-    from simplestreams.util import checksummer
-
-
 maaslog = get_maas_logger("bootresources")
 
 # Used by maasserver.middleware.AccessMiddleware to allow
@@ -659,7 +653,7 @@
         """Writes the data from the given reader, into the object storage
         for the given `BootResourceFile`."""
         ident = self.get_resource_file_log_identifier(rfile)
-        cksummer = checksummer(
+        cksummer = sutil.checksummer(
             {'sha256': rfile.largefile.sha256})
         maaslog.debug("Finalizing boot image %s.", ident)