ImportError: cannot import name ConsistentHashSortOrder

[Paul Greenberg]

When running `bagpipe-bgp`, I receive the following error:

```
Traceback (most recent call last):
  File "/usr/bin/bagpipe-bgp", line 6, in <module>
    from networking_bagpipe.bagpipe_bgp.bgp_daemon import daemon_main
  File "/usr/lib/python2.7/site-packages/networking_bagpipe/bagpipe_bgp/bgp_daemon.py", line 28, in <module>
    from networking_bagpipe.bagpipe_bgp.engine import exabgp_peer_worker
  File "/usr/lib/python2.7/site-packages/networking_bagpipe/bagpipe_bgp/engine/__init__.py", line 42, in <module>
    from networking_bagpipe.bagpipe_bgp.engine import exa
  File "/usr/lib/python2.7/site-packages/networking_bagpipe/bagpipe_bgp/engine/exa.py", line 34, in <module>
    from exabgp.bgp.message.update.attribute.community.extended \
ImportError: cannot import name ConsistentHashSortOrder
```

Additional information:

```
# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.3 (Maipo)

# exabgp --version
ExaBGP : 3.4.17
Python : 2.7.5 (default, Aug 2 2016, 04:20:16) [GCC 4.8.5 20150623 (Red Hat 4.8.5-4)]
Uname : #1 SMP Mon Feb 20 02:37:52 EST 2017
```

The issue might be related to this PR https://github.com/Exa-Networks/exabgp/pull/444

[Paul Greenberg (greenpau)]

Relevant code:

http://git.openstack.org/cgit/openstack/networking-bagpipe/tree/networking_bagpipe/bagpipe_bgp/engine/exa.py#n34

[Paul Greenberg (greenpau)]

Commented out the line:

```
#from exabgp.bgp.message.update.attribute.community.extended \
# import ConsistentHashSortOrder
```

Then, had an issue with several others. Had to comment out and amend.

```
#from exabgp.bgp.message.update.attribute.community.extended \
# import RouteTarget as RTExtCom

from exabgp.bgp.message.update.attribute.community.extended.rt import RouteTarget as RTExtCom

#from exabgp.bgp.message.update.attribute.community.extended \
# import RouteTargetASN2Number as RouteTarget

from exabgp.bgp.message.update.attribute.community.extended.rt \
    import RouteTargetASN4Number as RouteTarget

```

Next, the errors continue:

```
    from exabgp.bgp.message.update.attribute.community.extended.rt_record import RTRecord
ImportError: No module named rt_record
```

[Paul Greenberg (greenpau)]

The issues got resolved when I installed the `exabgp` from Github. Before, I used `exabgp` from `pip install`.

```
cd ~ && git clone https://github.com/Exa-Networks/exabgp.git
cd ~/exabgp && git log

commit 15dfe038d41e0c2c2622bd4e28d548a7b248a02d
Merge: 0067c0e 88ef753
Author: Vincent Bernat <email address hidden>
Date: Thu Mar 16 15:07:20 2017 +0100

    Merge pull request #587 from aj-gh/healthcheck-dynip-fix

    healthcheck.py: Fix nonexistent option name - ips_deleted vs. ip_dynamic
```

Finally:

```
cd ~/exabgp && python setup.py install
```

Now, no failures:

```
# bagpipe-bgp --version
bagpipe-bgp 6.0.1.dev68
#
```

[Thomas Morin (tmmorin-orange)]

Again, sorry for failing to follow up on this.

You correctly guessed that exabgp 3.x is not recent enough for networking-bagpipe.
You need to use a exabgp >= 4.0.x

The next release of networking-bagpipe shipping with bagpipe-bgp in it will soon be released and will be installable with:

  pip install -c https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt?h=stable/pike networking-bagpipe=7.0.0

In the meantime, you need to git clone, installing with "pip install -c https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt?h=stable/pike . " will install networking-bagpipe with correct dependencies.

[Thomas Morin (tmmorin-orange)]

Sorry, the last paragraph should have been:

In the meantime, you need to git clone, installing with "pip install -c https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt?h=master . " will install networking-bagpipe with correct dependencies.