From feb4539e0fbc7fefb1af709ab2f82ac242f586c7 Mon Sep 17 00:00:00 2001 From: Brian Rosmaita Date: Thu, 20 Jul 2017 22:11:07 -0400 Subject: [PATCH] Add release note for wsgi containerization Change-Id: I9dba62379b713dff596de9c4fc25dceb77581bfa --- ...sgi-containerization-369880238a5e793d.yaml | 44 +++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 releasenotes/notes/wsgi-containerization-369880238a5e793d.yaml diff --git a/releasenotes/notes/wsgi-containerization-369880238a5e793d.yaml b/releasenotes/notes/wsgi-containerization-369880238a5e793d.yaml new file mode 100644 index 0000000000..fc48591ee8 --- /dev/null +++ b/releasenotes/notes/wsgi-containerization-369880238a5e793d.yaml @@ -0,0 +1,44 @@ +--- +features: + - | + Glance is now packaged with a WSGI script entrypoint, enabling it to be + run as a WSGI application hosted by a performant web server. See `Running + Glance in HTTPD + `_ + in the Glance documentation for details. + + There are some limitations with this method of deploying Glance and we + do not recommend its use in production environments at this time. See + the `Known Issues`_ section of this document for more information. + +issues: + - | + Although support has been added for Glance to be run as a WSGI application + hosted by a web server, the atypical nature of the Images APIs provided by + Glance, which enable transfer of copious amounts of image data, makes it + difficult for this approach to work without careful configuration. Glance + relies on the use of chunked transfer encoding for image uploads, and + the support of chunked transfer encoding is not required by the + `WSGI specification`_. + + The Glance documentation section `Running Glance in HTTPD`_ outlines some + approaches to use (and not to use) Glance with the Apache httpd server. This + is the way Glance is configured as a WSGI application in devstack, so it's + the method with which we've had the most experience. If you try deploying + Glance using a different web server, please consider contributing your + findings to the Glance documentation. + + Currently, we are experiencing some problems in the gate when Glance is + configured to run in devstack following the guidelines recommended in the + documentation. You can follow `Bug 1703856`_ to learn more. + + As far as the Glance team can determine, the difficulties running Glance + as a WSGI application are caused by issues external to Glance. Thus + the Glance team recommends that Glance be run in its normal standalone + configuration, particularly in production environments. If you choose + to run Glance as a WSGI application in a web server, be sure to test + your installation carefully with realistic usage scenarios. + + .. _`WSGI specification`: https://www.python.org/dev/peps/pep-0333/ + .. _`Running Glance in HTTPD`: https://docs.openstack.org/glance/latest/admin/apache-httpd.html + .. _`Bug 1703856`: https://bugs.launchpad.net/glance/+bug/1703856