en/glep/glep-0060.txt

GLEP: 60
Title: Manifest2 filetypes
Version: $Revision: 1.7 $
Last-Modified: $Date: 2010/01/13 03:26:53 $
Author: Robin Hugh Johnson <robbat2@gentoo.org> 
Status: Draft
Type: Standards Track
Content-Type: text/x-rst
Requires: 44
Created: November 2007
Updated: June 2008, July 2008, October 2008, January 2010
Updates: 44
Post-History: December 2009, January 2010

Abstract
========
Clarification of the Manifest2 [#GLEP44] specification, including new types to
help in the tree-signing specification.

Motivation
==========
[#GLEP44] was not entirely clear on the usage of filetype specifiers.
This document serves to provide some of the internal logic used by
Portage at the point of writing, as well as adding new types to cover
the rest of the tree, for the purposes of tree-signing coverage.

This GLEP is not mandatory for the tree-signing specification, but
instead aims to clarify the usage of the Manifest2 filetype specifiers,
and note which types signify files that are allowed to be missing from
the tree (e.g. a user excluding a package or category).

Specification
=============
General
-------
For any given directory with a Manifest file, every file located in that
directory, or a sub-directory must be listed in that Manifest file,
unless stated otherwise in the following sections. The Manifest file
must not contain an entry for itself.

Excluded files
--------------
When generating or validating a Manifest, or committing to a version
control system, the package manager should endeavour to ignore files
created by a version control system, backup files from text editors. A
non-exhaustive list is suggested here: ``CVS/``, ``.svn/``, ``.bzr/``,
``.git/``, ``.hg/``, ``.#*``, ``*.rej``, ``*.orig``, ``*.bak``, ``*~``.

Additionally, for a transitional Manifest1->Manifest2 system, old-style
digest files located in a 'files/' directory, may be excluded from
Manifest2 generation, or included with a type of MISC.

Under strict security conditions, the exclusion list may be ignored
during validation if the existence of a file would be considered a
security risk.

Existing filetypes:
-------------------
AUX
~~~
- The AUX type is used for all items under the 'files' subdirectory. 
- They should be verified relative to $FILESDIR. 
- The string 'files/' is left out of the Manifest line. 
- The absence of a file mentioned by AUX must be treated as an error. 
- The AUX type is intended to denote potentially executable content
  (either directly or indirectly), that must be treated an error if
  modified or absent.

EBUILD
~~~~~~
- The EBUILD type is used solely for files ending in .ebuild, or other
  suffixes as defined by the EAPI.
- The files are located in the same directory as the Manifest file. 
- The modification or absence of a file mentioned by EBUILD must be
  treated as an error.

DIST
~~~~
- The DIST type is used for distfiles
- They may be found directly via the $DISTDIR setting of the package
  manager. 
- During simple verification of a Manifest, a missing DIST file should
  not be consider as a validation error (it is however a failure to
  fetch or unpack).

MISC
~~~~
- The MISC type covers all remaining files in a directory. 
- MISC is intended to mark all content that was not used in
  some way that directly affected execution of the package manager. 
- This includes metadata.xml and ChangeLog entries, and any other purely
  informational content.
- MISC entries where the file is missing may optionally be ignored as by
  non-strict package managers.
- It should be possible to install a package while all MISC entries have
  been deleted from the tree.


New filetypes:
--------------
_INFO (new, abstract)
~~~~~~~~~~~~~~~~~~~~~
- This is the functionality of the old AUX, but does not include the
  implicit 'files/' prefix in the path, and is verified relative to the
  working directory instead of $FILESDIR.
- The modification or absence of a file listed as a _INFO-derived type 
  is not an error unless the package manager is attempting to be strict.

_CRIT (new, abstract)
~~~~~~~~~~~~~~~~~~~~~
- _CRIT is based off the _INFO type.
- The modification or absence of a file listed as a _CRIT-derived type 
  MUST be treated as an error.

EBUILD
~~~~~~
- Now derived from _CRIT.
- Otherwise unchanged.

DIST
~~~~
- Now derived from _CRIT.
- Otherwise unchanged.

MISC
~~~~
- Now derived from _INFO.
- Otherwise unchanged.

MANIFEST (new)
~~~~~~~~~~~~~~
- The MANIFEST type is explicitly to cover all nested Manifest files.
- During validation, this serves as an indicator that the package
  manager may need to check subtree Manifest file. 
- A missing MANIFEST file may be treated as a minor (e.g. excluding an
  entire category) or critical validation failure.
- The failure should be considered as critical only if files that would
  be directly covered by this Manifest are missing. Deletion of a
  category-level Manifest while preserving the packages is forbidden.
  Deletion of an entire category is not.

ECLASS (new)
~~~~~~~~~~~~
- uses _CRIT.
- This type shall be used for all eclasses only.

DATA (new)
~~~~~~~~~~
- uses _CRIT.
- The DATA type shall be used for all files that directly affect the
  package manager, such as metadata/cache/* and profiles/.

EXEC (new)
~~~~~~~~~~
- uses _CRIT.
- If the file gets sourced, executed, or causes a change (patches) in
  how something is sourced or executed, it belongs in the EXEC
  filetype.
- This filetype should be used for the scripts directories of a
  repository for important files.
- This filetype is not limited to being used in the files/
  subdirectory.

OTHER (new)
~~~~~~~~~~~
- uses _CRIT.
- All other files that are not covered by another type should be
  considered as 'OTHER'.
- Any further new filetypes should be introduced to subtract files
  from the 'OTHER' set.
- If a package manager runs into a unknown Manifest2 type, it should
  be treated as 'OTHER'.

On Bloat
--------
If repeated use of a common path prefix is considered a bloat problem, a
Manifest file should be added inside the common directory, however this
should not be done blindly, as bloat by inodes is more significant for
the majority of use cases. See also [#GLEP58] on size reductions of
Manifests.

Chosing a filetype
------------------
1. matches ``Manifest``
    => MANIFEST, stop.
2. matches ``*.ebuild``
    => EBUILD, stop.
3. matches ``*.eclass``
    => ECLASS, stop.
4. listed in SRC_URI 
    => DIST, stop.
5. matches ``files/*``
    => AUX, continue [see note].
6. matches any of ``*.sh``, ``*.bashrc``, ``*.patch``, ...
    => EXEC, stop.
7. matches any of ``metadata/cache/*``, ``profiles/``, ``package.*``, ``use.mask*``, ...
    => DATA, stop.
8. matches any of ``ChangeLog``, ``metadata.xml``, ``*.desc``, ...
    => MISC, stop.
9. not matched by any other rule 
    => OTHER, stop.

The logic behind 5, 6, 7 is ensuring that every item that by it's
presence or absence may be dangerous should always be treated strictly.
(Consider epatch given a directory of patches ``${FILESDIR}/${PV}/``,
where it blindly includes them, or alternatively, the package.mask file
or a profile being altered/missing).

The above lists of file patterns are not intended to be exhaustive,
but merely demonstrative.

Note: The AUX entries should only be generated if we are generating a
compatible Manifest that supports older versions of Portage. They should
be generated along with the new type.

Backwards Compatibility
=======================
For generation of existing package Manifests, the AUX entries must
continue to be present for the standard Portage deprecation cycle.
The new entries may be included already in all Manifest files, as they
will be ignored by older Portage versions. Over time, ECLASS, DATA,
EXEC, OTHER may replace the existing AUX type.

The adoption of this proposal does also affect [#GLEP58] as part of
this GLEP series, however this GLEP was an offset of the research in
that GLEP.

Thanks to
=========
I'd like to thank the following people for input on this GLEP.
- Marius Mauch (genone) & Zac Medico (zmedico): Portage Manifest2

References
==========
.. [#GLEP44] Mauch, M. (2005) GLEP44 - Manifest2 format.
  http://www.gentoo.org/proj/en/glep/glep-0044.html     

Copyright
=========
Copyright (c) 2007-2010 by Robin Hugh Johnson. This material may be
distributed only subject to the terms and conditions set forth in the
Open Publication License, v1.0.

vim: tw=72 ts=2 expandtab:
1	GLEP: 60
2	Title: Manifest2 filetypes
3	Version: $Revision: 1.7 $
4	Last-Modified: $Date: 2010/01/13 03:26:53 $
5	Author: Robin Hugh Johnson <robbat2@gentoo.org>
6	Status: Draft
7	Type: Standards Track
8	Content-Type: text/x-rst
9	Requires: 44
10	Created: November 2007
11	Updated: June 2008, July 2008, October 2008, January 2010
12	Updates: 44
13	Post-History: December 2009, January 2010
14
15	Abstract
16	========
17	Clarification of the Manifest2 [#GLEP44] specification, including new types to
18	help in the tree-signing specification.
19
20	Motivation
21	==========
22	[#GLEP44] was not entirely clear on the usage of filetype specifiers.
23	This document serves to provide some of the internal logic used by
24	Portage at the point of writing, as well as adding new types to cover
25	the rest of the tree, for the purposes of tree-signing coverage.
26
27	This GLEP is not mandatory for the tree-signing specification, but
28	instead aims to clarify the usage of the Manifest2 filetype specifiers,
29	and note which types signify files that are allowed to be missing from
30	the tree (e.g. a user excluding a package or category).
31
32	Specification
33	=============
34	General
35	-------
36	For any given directory with a Manifest file, every file located in that
37	directory, or a sub-directory must be listed in that Manifest file,
38	unless stated otherwise in the following sections. The Manifest file
39	must not contain an entry for itself.
40
41	Excluded files
42	--------------
43	When generating or validating a Manifest, or committing to a version
44	control system, the package manager should endeavour to ignore files
45	created by a version control system, backup files from text editors. A
46	non-exhaustive list is suggested here: ``CVS/``, ``.svn/``, ``.bzr/``,
47	``.git/``, ``.hg/``, ``.#``, ``.rej``, ``.orig``, ``.bak``, ``*~``.
48
49	Additionally, for a transitional Manifest1->Manifest2 system, old-style
50	digest files located in a 'files/' directory, may be excluded from
51	Manifest2 generation, or included with a type of MISC.
52
53	Under strict security conditions, the exclusion list may be ignored
54	during validation if the existence of a file would be considered a
55	security risk.
56
57	Existing filetypes:
58	-------------------
59	AUX
60	~~~
61	- The AUX type is used for all items under the 'files' subdirectory.
62	- They should be verified relative to $FILESDIR.
63	- The string 'files/' is left out of the Manifest line.
64	- The absence of a file mentioned by AUX must be treated as an error.
65	- The AUX type is intended to denote potentially executable content
66	(either directly or indirectly), that must be treated an error if
67	modified or absent.
68
69	EBUILD
70	~~~~~~
71	- The EBUILD type is used solely for files ending in .ebuild, or other
72	suffixes as defined by the EAPI.
73	- The files are located in the same directory as the Manifest file.
74	- The modification or absence of a file mentioned by EBUILD must be
75	treated as an error.
76
77	DIST
78	~~~~
79	- The DIST type is used for distfiles
80	- They may be found directly via the $DISTDIR setting of the package
81	manager.
82	- During simple verification of a Manifest, a missing DIST file should
83	not be consider as a validation error (it is however a failure to
84	fetch or unpack).
85
86	MISC
87	~~~~
88	- The MISC type covers all remaining files in a directory.
89	- MISC is intended to mark all content that was not used in
90	some way that directly affected execution of the package manager.
91	- This includes metadata.xml and ChangeLog entries, and any other purely
92	informational content.
93	- MISC entries where the file is missing may optionally be ignored as by
94	non-strict package managers.
95	- It should be possible to install a package while all MISC entries have
96	been deleted from the tree.
97
98
99	New filetypes:
100	--------------
101	_INFO (new, abstract)
102	~~~~~~~~~~~~~~~~~~~~~
103	- This is the functionality of the old AUX, but does not include the
104	implicit 'files/' prefix in the path, and is verified relative to the
105	working directory instead of $FILESDIR.
106	- The modification or absence of a file listed as a _INFO-derived type
107	is not an error unless the package manager is attempting to be strict.
108
109	_CRIT (new, abstract)
110	~~~~~~~~~~~~~~~~~~~~~
111	- _CRIT is based off the _INFO type.
112	- The modification or absence of a file listed as a _CRIT-derived type
113	MUST be treated as an error.
114
115	EBUILD
116	~~~~~~
117	- Now derived from _CRIT.
118	- Otherwise unchanged.
119
120	DIST
121	~~~~
122	- Now derived from _CRIT.
123	- Otherwise unchanged.
124
125	MISC
126	~~~~
127	- Now derived from _INFO.
128	- Otherwise unchanged.
129
130	MANIFEST (new)
131	~~~~~~~~~~~~~~
132	- The MANIFEST type is explicitly to cover all nested Manifest files.
133	- During validation, this serves as an indicator that the package
134	manager may need to check subtree Manifest file.
135	- A missing MANIFEST file may be treated as a minor (e.g. excluding an
136	entire category) or critical validation failure.
137	- The failure should be considered as critical only if files that would
138	be directly covered by this Manifest are missing. Deletion of a
139	category-level Manifest while preserving the packages is forbidden.
140	Deletion of an entire category is not.
141
142	ECLASS (new)
143	~~~~~~~~~~~~
144	- uses _CRIT.
145	- This type shall be used for all eclasses only.
146
147	DATA (new)
148	~~~~~~~~~~
149	- uses _CRIT.
150	- The DATA type shall be used for all files that directly affect the
151	package manager, such as metadata/cache/* and profiles/.
152
153	EXEC (new)
154	~~~~~~~~~~
155	- uses _CRIT.
156	- If the file gets sourced, executed, or causes a change (patches) in
157	how something is sourced or executed, it belongs in the EXEC
158	filetype.
159	- This filetype should be used for the scripts directories of a
160	repository for important files.
161	- This filetype is not limited to being used in the files/
162	subdirectory.
163
164	OTHER (new)
165	~~~~~~~~~~~
166	- uses _CRIT.
167	- All other files that are not covered by another type should be
168	considered as 'OTHER'.
169	- Any further new filetypes should be introduced to subtract files
170	from the 'OTHER' set.
171	- If a package manager runs into a unknown Manifest2 type, it should
172	be treated as 'OTHER'.
173
174	On Bloat
175	--------
176	If repeated use of a common path prefix is considered a bloat problem, a
177	Manifest file should be added inside the common directory, however this
178	should not be done blindly, as bloat by inodes is more significant for
179	the majority of use cases. See also [#GLEP58] on size reductions of
180	Manifests.
181
182	Chosing a filetype
183	------------------
184	1. matches ``Manifest``
185	=> MANIFEST, stop.
186	2. matches ``*.ebuild``
187	=> EBUILD, stop.
188	3. matches ``*.eclass``
189	=> ECLASS, stop.
190	4. listed in SRC_URI
191	=> DIST, stop.
192	5. matches ``files/*``
193	=> AUX, continue [see note].
194	6. matches any of ``.sh``, ``.bashrc``, ``*.patch``, ...
195	=> EXEC, stop.
196	7. matches any of ``metadata/cache/``, ``profiles/``, ``package.``, ``use.mask*``, ...
197	=> DATA, stop.
198	8. matches any of ``ChangeLog``, ``metadata.xml``, ``*.desc``, ...
199	=> MISC, stop.
200	9. not matched by any other rule
201	=> OTHER, stop.
202
203	The logic behind 5, 6, 7 is ensuring that every item that by it's
204	presence or absence may be dangerous should always be treated strictly.
205	(Consider epatch given a directory of patches ``${FILESDIR}/${PV}/``,
206	where it blindly includes them, or alternatively, the package.mask file
207	or a profile being altered/missing).
208
209	The above lists of file patterns are not intended to be exhaustive,
210	but merely demonstrative.
211
212	Note: The AUX entries should only be generated if we are generating a
213	compatible Manifest that supports older versions of Portage. They should
214	be generated along with the new type.
215
216	Backwards Compatibility
217	=======================
218	For generation of existing package Manifests, the AUX entries must
219	continue to be present for the standard Portage deprecation cycle.
220	The new entries may be included already in all Manifest files, as they
221	will be ignored by older Portage versions. Over time, ECLASS, DATA,
222	EXEC, OTHER may replace the existing AUX type.
223
224	The adoption of this proposal does also affect [#GLEP58] as part of
225	this GLEP series, however this GLEP was an offset of the research in
226	that GLEP.
227
228	Thanks to
229	=========
230	I'd like to thank the following people for input on this GLEP.
231	- Marius Mauch (genone) & Zac Medico (zmedico): Portage Manifest2
232
233	References
234	==========
235	.. [#GLEP44] Mauch, M. (2005) GLEP44 - Manifest2 format.
236	http://www.gentoo.org/proj/en/glep/glep-0044.html
237
238	Copyright
239	=========
240	Copyright (c) 2007-2010 by Robin Hugh Johnson. This material may be
241	distributed only subject to the terms and conditions set forth in the
242	Open Publication License, v1.0.
243
244	vim: tw=72 ts=2 expandtab: