openstack/api-sig
Code Issues Proposed changes

Added tags restrictions to the tagging guidelines

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One problem with tag names was found during tag
implementation in Nova Ibc44228aeae94c17353af7fccfcfb2c11b2e9190
This problems was connected with URLs. We can't
use '/' in names because in this case we will get a incorrect
URL for tag 'abc/cba': /servers/<server_id>/tags/abc/cba
Even if '/' will be encoded like %2F. Nova will decide
that it is '/'.

But this is not a problem of Nova. Unfortunately some servers
works incorrectly with encoded character '/'. It's a problem of poor
implementation of some servers. To escape problems with handling URLs
character '/' should be forbidden in tag names.

Change-Id: I9832270b3d8210bff9cd2d9732b4d19f757f865a
This commit is contained in:
Sergey Nikitin
2016-02-05 15:12:13 +03:00
parent 9aa075a2e3
commit 70cb95394d
1 changed files with 20 additions and 2 deletions
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22
guidelines/tags.rst
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@@ -18,8 +18,7 @@ Tags Representation
------------------- -------------------
Tags are strings attached to an entity with the purpose of classification into Tags are strings attached to an entity with the purpose of classification into
groups. To simplify requests that specify lists of tags, the comma character groups.
is not allowed to be in a tag name.
An entity can have zero, one or more tags associated with it, for that An entity can have zero, one or more tags associated with it, for that
reason the recommended representation within the parent entity is a list. reason the recommended representation within the parent entity is a list.
@@ -51,6 +50,25 @@ For resources that have a representation that is not in JSON a separate
endpoint must be created to expose the tags. See the "Tag Resource URLs" endpoint must be created to expose the tags. See the "Tag Resource URLs"
section below for more information. section below for more information.
Tags Restrictions
-----------------
Tags are strings with the following basic restrictions:
* Tags are case sensitive.
* '/' is **not** allowed to be in a tag name
* Comma is **not** allowed to be in a tag name in order to simplify requests
that specify lists of tags
* All other characters are allowed to be in a tag name
.. note::
The '/' character is forbidden because some servers have a problem with
encoding this character. The problem is that the server will handle '%2F'
as '/' even though '/' is encoded. It's a problem of poor server
implementation. To avoid problems with handling URLs character '/' is
forbidden in tag names.
Character Encoding for Tags Character Encoding for Tags
--------------------------- ---------------------------