Require Python 3 and remove support for Python 2.

Python 2 reaches end-of-life on January 1, 2020, which is only
a few months away.  This means that OVS needs to stop depending
on in the next release that should occur roughly that same time.
Therefore, this commit removes all support for Python 2.  It
also makes Python 3 a mandatory build dependency.

Some of the interesting consequences:

- HAVE_PYTHON, HAVE_PYTHON2, and HAVE_PYTHON3 conditionals have
  been removed, since we now know that Python3 is available.

- $PYTHON and $PYTHON2 are removed, and $PYTHON3 is always
  available.

- Many tests for Python 2 support have been removed, and the ones
  that depended on Python 3 now run unconditionally.  This allowed
  several macros in the testsuite to be removed, making the code
  clearer.  This does make some of the changes to the testsuite
  files large due to indentation level changes.

- #! lines for Python now use /usr/bin/python3 instead of
  /usr/bin/python.

- Packaging depends on Python 3 packages.

Acked-by: Numan Siddique <nusiddiq@redhat.com>
Tested-by: Numan Siddique <nusiddiq@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/.cirrus.yml b/.cirrus.yml
index eb6af0a71..bae5a089b 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -9,8 +9,7 @@ freebsd_build_task:
 
   env:
     DEPENDENCIES: automake libtool gmake gcc wget openssl
-                  python py27-six py27-sphinx py27-openssl
-                  python3 py36-six py36-openssl
+                  python3 py36-six py36-openssl p36-sphinx
     matrix:
       COMPILER: gcc
       COMPILER: clang