1================
2Packaging Policy
3================
4This document defines the policy for creating packages.
5
6Multiple Packages per Software
7==============================
8Installation files of a software shall be put into separated packages according
9to their purpose. For a software "foo":
10
11- Package "foo": Contains all runtime files, i.e. everything needed to "run" the
12  software. This may include executables (e.g. executable "bin/foo"), shared
13  libraries (e.g. "lib/libfoo.so"), data files
14  (e.g. "data/foo/foo-runtime-data").
15- Package "foo_devel": Contains only the files needed for development. This
16  includes header files and static libraries. Shared libraries are not to be
17  included. Instead the package must declare package "foo" with the matching
18  version as a requirement.
19- Package "foo_doc": Contains the documentation for using "foo".
20- Package "foo_devel_doc": Contains the documentation for "foo" development,
21  like API documentation etc.
22- Package "foo_debuginfo": Contains the debug information for the package "foo".
23
24If multiple packages are defined, they must not contain any common files.
25
26If a software contains client and server software that can be used independently
27from each other, two separate sets of packages shall be created.
28
29Provides Declaration
30====================
31A package "foo" must declare the following provided resolvables:
32
33- "foo=<version>" with <version> naming the exact version of the package.
34- "cmd:<name>=<version>" for each executable <name> with version <version>
35  installed in "bin/". This includes a declaration for "cmd:foo", if there is an
36  executable named like the package.
37- "lib:<name>=<version>" for each shared library <name> (not including a suffix,
38  e.g. "libfoo") with version <version> installed in "lib/".
39- "devel:<name>=<version>" for each library <name> (not including a suffix,
40  e.g. "libfoo") with version <version> for which development files (library
41  symlinks in "develop/lib" and header files in "develop/headers") are included.
42
43Any instance of '-' in <name> shall be replaced by '_'. If the backward
44compatibility of a resolvable is known, a "compat >= <compatibleVersion>" shall
45be added accordingly.
46
47Documentation
48=============
49If a package "foo" provides documentation (which it should, of course), in many
50cases that can be provided in different formats:
51
52- Any kind of user documentation belongs in a subdirectory of "documentation"
53
54  - Man pages is the preferred format for terminal and should be installed into
55    the corresponding folders in the subdirectory "man".
56  - Info files are provided by many packages. If at all desirable, they should
57    be installed into the subdirectory "info". One problem with info files is
58    that all packages currently contain a file named "documentation/info/dir",
59    which supposedly is the list of all available info files, but since each
60    package provides an instance of this file containing only its own info
61    files, an arbitrary dir file is made visible via packagefs. The file should
62    therefore not be include in a package.
63  - Other documentation for a package foo -- HTML, a simple ReadMe, sample
64    documents, PDFs, etc. -- goes into subdirectory "packages/foo". If it is
65    likely that multiple versions of a package may be installed, then a version
66    string (as appropriate just major, major and minor, or even full (but no
67    revision)) should be appended, e.g. "package/foo-2" or "package/foo-2.13".
68
69- For a package foo_devel developer documentation, except man and info pages,
70  should go into "develop/documentation/foo". A version string may be appended
71  to the directory name as well. When it is unclear what is developer
72  documentation or it isn't really possible to separate it from user
73  documentation "documentation/foo" should be used.
74
75Data Files
76==========
77Data files for a package foo shall generally be placed in a directory
78"data/foo". If it is likely that multiple versions of a package may be
79installed, then a version string shall be appended. Data (but not
80settings/configuration) files generated at run-time shall be placed in
81"cache/foo" or "var/foo", depending on the kind of data the files contain. For
82data files, both read-only or generated, that are shared between different
83packages/software a differently named subdirectory may be used as appropriate
84(e.g. font files are placed in "data/fonts").
85
86Writable and Settings Files and Directories
87===========================================
88All global writable files and directories as well as user settings files and
89directories that the package includes or the packaged software creates or
90requires the user to create shall be declared by the package (via
91GLOBAL_WRITABLE_FILES respectively USER_SETTINGS_FILES in the build recipe) in
92the following way:
93
94- A user specific settings file shall never be installed on package activation.
95  Usually user specific settings files are completely optional. In the rare case
96  that a software requires a user specific settings, the user will have to
97  create it manually. In either case, if the package includes a template user
98  settings file, that should be declared::
99
100    USER_SETTINGS_FILES="settings/foo template data/foo/user-settings-template"
101
102  If no template file is included, the settings file shall still be declared::
103
104    USER_SETTINGS_FILES="settings/foo"
105
106- Since many ported software requires a global settings file or other writable
107  files, a default version of such a file can be provided and is automatically
108  installed on package activation. In that case the package must also declare
109  what shall be done with a user-modified file when the package is updated.
110  E.g.::
111
112    GLOBAL_WRITABLE_FILES="settings/foo keep-old"
113
114  "keep-old" indicates that the software can read old files and the
115  user-modified file should be kept. "manual" indicates that the software may
116  not be able to read an older file and the user may have to manually adjust it.
117  "auto-merge" indicates that the file format is simple text and a three-way
118  merge shall be attempted. If a default settings file is not included in the
119  package, the settings file shall still be declared, just without the
120  additional keyword.
121
122In both cases, user settings files and global writable files, the "directory"
123keyword can be used to indicate that the given path actually refers to a
124directory.
125
126Post-Installation Scripts
127=========================
128A package may include one or more post-installation scripts. The scripts are
129executed whenever the package is activated (for the first time, but also after
130package updates and first boot of a newly installed OS). They shall be placed
131in "boot/post-install" and declared explicitly by the package (via
132POST_INSTALL_SCRIPTS in the build recipe). A post-install script should be
133considered the last resort. It should only be used, if there's no reasonable
134alternative.  A typical use would be to create a desktop icon that the user
135can move around or delete.
136
137Pre-Uninstallation Scripts
138==========================
139These undo the effects of a post-installation script and usually are put
140into "boot/pre-uninstall".  A typical use is to remove desktop icons.
141