Running Glance in HTTPD
In short Glance will not operate properly if tried to be ran without
eventlet and introducing another web server into the mix does not make
it any better. This exercise failed without ever having proper interest
or resources to fix the underlying issues.
None of the models deploying Glance as bare wsgi app under some httpd
are currently advised.
Since the Pike release Glance has packaged a wsgi script entrypoint
that enables you to run it with a real web server like Apache HTTPD or
nginx. To deploy this there are several patterns, which all fail
different ways. This doc mentions three common ways of trying to deploy
Glance with Apache HTTPD.
Warning
As pointed out in the Pike and Queens release notes (see the “Known
Issues” section of each), the Glance project team recommends that Glance
be run in its normal standalone configuration, particularly in
production environments. The full functionality of Glance is not
available when Glance is deployed in the manner described in this
document. In particular, the interoperable image import functionality
does not work under such configuration. See the release notes for
details.
uWSGI Server HTTP Mode
This has never worked properly nor it has been of any development
focus.
The clearest we can say is just don’t do it.
mod_proxy_uwsgi
This has not been doable since Ussuri as we only support Python
3.
In theory the same applies as mod_wsgi but even without chunked
encoding the code is still broken under uwsgi.
mod_wsgi
This deployment method is not recommended for using Glance. The
mod_wsgi protocol does not support
Transfer-Encoding: chunked and therefore makes it
unsuitable for use with Glance. However, you could theoretically deploy
Glance using mod_wsgi but it will fail on any requests that use a
chunked transfer encoding.
Glossary
- uwsgi protocol
-
The native protocol used by the uWSGI server. (The acronym is written
in all lowercase on purpose.) - uWSGI project
-
A project that aims at developing a full stack for building hosting
services. It produces software, the uWSGI server, that is exposed in
Python code as a module nameduwsgi.https://uwsgi-docs.readthedocs.io/en/latest/index.html
- mod_wsgi
-
An Apache 2 HTTP server module that supports the Python WSGI
specification. - mod_proxy_uwsgi
-
An Apache 2 HTTP Server module that provides a uwsgi gateway for
mod_proxy. It communicates to the uWSGI server using the uwsgi
protocol. - WSGI
-
Web Server Gateway Interface, a Python standard published as PEP 3333.