The current output for package-installs-v2 is inscrutable [1]
The problem starts with process_output() which is not capturing
stderr. This means that any stderr output is dislocated from any
stdout output around it. This is *really* confusing as you get a
bunch of seemingly meaningless stderr output from any calls before you
see any stdout (e.g. in [1] you can see random yum error output that
should have been with the yum call)). The simplest thing to do is to
redirect stderr to stdout which keeps everything in sync.
This causes a slight problem, however, because pkg-map outputs both
status information and errors on stderr. To work around this but
maintain compatibility, we add a "--prefix" argument that prepends
mapped packages from pkg-map with a value we can match on. The
existing status/debug output from pkg-map is low-value; modify the
call so that it will be traced only at higher debug levels (e.g. -x
-x).
The current loop is also calling pkg-map for every package in every
element (this is why in [1] the same message is repeated over and
over). This is unnecessary; it only needs to pkg-map once for each
element, giving the package list as the arguments. Create package
lists by element and pass those to pkg-map.
As a cleanup, there is no point in printing e.output if the
process_output fails for the install because we are already tracing
it; i.e. the output, even for failures, is already in the logs.
Printing it again just duplicates the output.
[2] is an extract showing what I feel is a much more understandable
log output for a fairly complex install.
[1] http://paste.openstack.org/show/595118/
[2] http://paste.openstack.org/show/595303/
Change-Id: Ia74602a5d2db032a476481caec0e45dab013d54f
f068e6aa6e