tripleo-specs/specs/juno/haproxy_configuration.rst
Robert Collins 2cc5b31b54 Tweak HAProxy spec to deal with mixed services.
Turns out we didn't dig deep enough when designing it.

Change-Id: I144e627465d4a28ad692c14c03c1ec6387ef1f86
2014-08-11 11:42:43 +12:00

230 lines
5.6 KiB
ReStructuredText

..
This work is licensed under a Creative Commons Attribution 3.0 Unported
License.
http://creativecommons.org/licenses/by/3.0/legalcode
================================================
Haproxy ports and related services configuration
================================================
Blueprint: https://blueprints.launchpad.net/tripleo/+spec/tripleo-haproxy-configuration
Current spec provides options for HA endpoints delivery via haproxy.
Problem Description
===================
Current tripleo deployment scheme binds services on 0.0.0.0:standard_port,
with stunnel configured to listen on ssl ports.
This configuration has some drawbacks and wont work in ha, for several reasons:
* haproxy cant bind on <vip_address>:<service_port> - openstack services are
bound to 0.0.0.0:<service_port>
* services ports hardcoded in many places (any_service.conf, init-keystone),
so changing them and configuring from heat would be a lot of pain
* the non-ssl endpoint is reachable from outside the local host,
which could potentially confuse users and expose them to an insecure connection
in the case where we want to run that service on SSL only. We want to offer SSL
by default but we can't really prevent it.
Proposed Change
===============
We will bind haproxy, stunnel (ssl), openstack services on ports with
different ipaddress settings.
HAProxy will be bound to VIP addresses only.
STunnel where it is used will be bound to the controller ctlplane address.
OpenStack services will bind to localhost for SSL only configurations, and to
the ctlplane address for non-SSL or mixed-mode configurations. They will bind
to the standard non-encrypted ports, but will never bind to 0.0.0.0 on any
port.
We'll strive to make SSL-only the default.
An example, using horizon in mixed mode (HTTPS and HTTP):
vip_address = 192.0.2.21
node_address = 192.0.2.24
1. haproxy
listen horizon_http
bind vip_address:80
server node_1 node_address:80
listen horizon_https
bind vip_address:443
server node_1 node_address:443
2. stunnel
accept node_address:443
connect node_address:80
3. horizon
bind node_address:80
A second example, using horizon in HTTPS only mode:
vip_address = 192.0.2.21
node_address = 192.0.2.24
1. haproxy
listen horizon_https
bind vip_address:443
server node_1 node_address:443
2. stunnel
accept node_address:443
connect 127.0.0.1:80
3. horizon
bind 127.0.0.1:80
Alternatives
------------
There are several alternatives which do not cover all the requirements for
security or extensibility
Option 1: Assignment of different ports for haproxy, stunnel, openstack services on 0.0.0.0
* requires additional firewall configuration
* security issue with non-ssl services endpoints
1. haproxy
bind :80
listen horizon
server node_1 node_address:8800
2. stunnel
accept :8800
connect :8880
3. horizon
bind :8880
Option 2: Using only haproxy ssl termination is suboptimal:
* 1.5 is still in devel phase -> potential stability issues
* we would have to get this into supported distros
* this also means that there is no SSL between haproxy and real service
* security issue with non-ssl services endpoints
1. haproxy
bind vip_address:80
listen horizon
server node_1 node_address:80
2. horizon
bind node_address:80
Option 3: Add additional ssl termination before load-balancer
* not useful in current configuration because load balancer (haproxy)
and openstack services installed on same nodes
Security Impact
---------------
* Only ssl protected endpoints are publicly available if running SSL only.
* Minimal firewall configuration
* Not forwarding decrypted traffic over non-localhost connections
* compromise of a control node exposes all external traffic (future and possibly past)
to decryption and/or spoofing
Other End User Impact
---------------------
Several services will listen on same port, but it will be quite easy
to understand if user (operator) will know some context.
Performance Impact
------------------
No differences between approaches.
Other Deployer Impact
---------------------
None
Developer Impact
----------------
None
Implementation
==============
We need to make the service configs - nova etc - know on a per service basis
where to bind. The current approach uses logic in the template to choose
between localhost and my_ip. If we move the selection into Heat this can
become a lot simpler (read a bind address, if set use it, if not don't).
We considered extending the connect_ip concept to be on a per service basis.
Right now all services are exposed to both SSL and plain, so this would be
workable until we get a situation where only some services are plain - but we
expect that sooner rather than later.
Assignee(s)
-----------
Primary assignee:
dshulyak
Work Items
----------
tripleo-incubator:
* build overcloud-control image with haproxy element
tripleo-image-elements:
* openstack-ssl element refactoring
* refactor services configs to listen on 127.0.0.1 / ctlplane address:
horizon apache configuration, glance, nova, cinder, swift, ceilometer,
neutron, heat, keystone, trove
tripleo-heat-templates:
* add haproxy metadata to heat-templates
Dependencies
============
None
Testing
=======
CI testing dependencies:
* use vip endpoints in overcloud scripts
* add haproxy element to overcloud-control image (maybe with stats enabled) before
adding haproxy related metadata to heat templates
Documentation Impact
====================
* update incubator manual
* update elements README.md
References
==========
http://haproxy.1wt.eu/download/1.4/doc/configuration.txt
https://www.stunnel.org/howto.html