Hello,
Please find below a proposal to add a configuration package to centralize
environment variables definitions (and a little more).
Best Regards,
Stéphane
--
Stéphane Desneux
Intel OTC - Vannes/FR
Tizen 3.x: per-profile paths/environment configuration
======================================================
This is a proposal to have a unique package that defines how the environment
variables are made available to an application running in userland.
* 1 source package per profile
- naming proposal: 'tizen-env-$profile' (ex: tizen-env-mobile, tizen-env-ivi
...)
- could be made updatable by an oem for device customization
* 1 main source file (in any convenient format: sh-like, yaml, xml, json, ini
...)
2 kinds of variables reserved for Tizen:
- system variables (paths are absolute here): TZ_SYS_XXXXX
- user variables (relative to user home dir at definition time):
TZ_USER_REL_XXXXXX
other user/system variables not related to paths could be defined too...
Example:
TZ_SYS_DB="/var/db" for global databases dir
TZ_USER_REL_DB=".tizen/db" for user database dir (relative to user home
dir)
TZ_USER_DB="/home/<username>/.config/db" : the user variable not defined
but resolved at runtime
* 2 generated binary packages:
- binary package tizen-env-$profile-devel would contain:
=> /usr/include/tizen-env.h
...
/* for global static paths: */
static const char *TZ_SYS_DB="/var/db";
...
/* for user specific paths, use TZ_USER_REL_XXXXX naming: */
static const char* TZ_USER_REL_DB="db";
...
/* no expanded user varisbles TZ_USER_XXX as they will be resolved at
runtime with getenv() */
=> /usr/share/pkgconfig/tizen-env.pc
allows the use of system paths at build time (without using the header)
=> do we add a helper that could be used in other source files ? For
example, a wrapper around getenv() that would do the job in particular for user
variables to be resolved at runtime (depends on uid, username, home dir etc.):
const char* tzgetenv(const char* name) {
... if name is a TZ_XXX variable, resolve it with tizen-env.h header
definitions (use the real env variable or not)
... else return getenv() result
}
=> the same helper can be coded in python, javascript ... or any language
which has a way to access to environment variables
- binary package tizen-env-$profile containing "sourceable" files which could
be located in different places:
=> /etc/environment (sourced by pam)
=> /etc/profile.d/tizen-env.sh (sourced by any login shell)
=> /etc/tizen-env.py
=> /etc/tizen-env.ini (section [system], [user] ...)
=> ... other suitable formats (json, XML, ...) and places if needed
Variables to be set in app environment
--------------------------------------
* Historical vars: HOME, TERM, SHELL, USER, LOGNAME, LANG, PATH ...
* XDG variables:
- XDG_SESSION_ID
- XDG_RUNTIME_DIR
- XDG_CONFIG_DIRS
- XDG_DATA_DIRS
- ...
* daemon specific vars:
- DISPLAY
- WAYLAND_DISPLAY
- DBUS_SESSION_BUS_ADDRESS
- ...
* "Tizen vars" set by a file installed by tizen-env-$profile:
- global static paths
. TZ_SYS_HOME : the directory containing the home dirs
. TZ_SYS_DB: database directory
. TZ_SYS_CONFIG: vconf directory
. TZ_SYS_CONFIG_VOLATILE: vconf directory (for volatile files AKA 'memory'
vconf)
. TZ_SYS_APP: applications install dir
. TZ_SYS_DESKTOP_APP: desktop files dir
- user paths, resolved as relative to user home dir
. TZ_USER_DB: user database dir
. TZ_USER_CONFIG: user vconf dir
. TZ_USER_APP: user applications dir
. TZ_USER_DESKTOP_APP: user desktop files dir
. TZ_USER_DOCUMENTS: user documents dir
. TZ_USER_PICTURES: user pictures dir
. TZ_USER_VIDEOS ...
. TZ_USER_MUSIC
. TZ_USER_DOWNLOADS
. TZ_USER_PUBLIC: shared content
. ...
- other global variables TZ_SYS_???
- other user variables TZ_USER_???
* to be completed
Tizen variables compatibility
-----------------------------
Initially, when applications won't have migrated yet, we could use Tizen 2.X
compatible values for smooth transition (*PATHS VALUES MUST BE CONFIRMED FROM
ACTUAL IMAGES*):
TZ_SYS_HOME=/opt/home
TZ_SYS_DB=/opt/dbspace
TZ_SYS_CONFIG=/opt/var/kdb
TZ_SYS_CONFIG_VOLATILE=/opt/var/kdb
TZ_SYS_APP=/opt/apps
TZ_SYS_DESKTOP_APP=/opt/share/applications
TS_USER_DB=../../opt/usr/dbspace
TZ_USER_CONFIG=../../opt/var/kdb
TZ_USER_APP=../../opt/usr/apps
TZ_USER_DESKTOP_APP=../../usr/share/applications
TZ_USER_DOCUMENTS=../../opt/home/app/Documents
TZ_USER_PICTURES=../../opt/home/app/Pictures
TZ_USER_VIDEOS=../../opt/home/app/Videos
TZ_USER_MUSIC=../../opt/home/app/Music
TZ_USER_DOWNLOADS=../../opt/home/app/Downloads
TZ_USER_PUBLIC=../../opt/home/app/Public
...
=> new (migrated) apps will use the variables and old (non-migrated) ones will
still have their hardcoded paths. As they're identical, this will probably
ensure a smooth transition.
Tizen 3.x values with multiuser up (*paths are just given as examples, this is
not a proposal for the paths*):
TZ_SYS_HOME=/home
TZ_SYS_DB=/var/db
TZ_SYS_CONFIG=/var/kdb
TZ_SYS_CONFIG_VOLATILE=/run/kdb
TZ_SYS_APP=/usr/apps
TZ_SYS_DESKTOP_APP=/usr/share/applications
TS_USER_DB=<user_homeid>/.tizen/db
TZ_USER_CONFIG=<user_home_dir>/.tizen/kdb
TZ_USER_APP=<user_home_dir>/.tizen/apps
TZ_USER_DESKTOP_APP=<user_home_dir>/.tizen/desktop
TZ_USER_DOCUMENTS=<user_home_dir>/Documents
TZ_USER_PICTURES=<user_home_dir>/Pictures
TZ_USER_VIDEOS=<user_home_dir>/Videos
TZ_USER_MUSIC=<user_home_dir>/Music
TZ_USER_DOWNLOADS=<user_home_dir>/Downloads
TZ_USER_PUBLIC=<user_home_dir>/Public
...
=> when this new configuration will be set up, non-migrated apps will (MUST?)
fail.
Variables initialization
------------------------
A good place to initialize the environment variables is the PAM session start.
This could be done by a PAM module I proposed to write (previously this month:
https://lists.tizen.org/pipermail/dev/2013-October/000363.html).
This module would read the global configuation file containing the definitions
(TZ_SYS_??? and TZ_USER_REL_??? vars) and create the appropriate env vars in
the session.
In particular, the TZ_USER_XXX variables are always built from the user home
dir and the relative variable TZ_USER_REL_XXX. So we have multiple choices to
build the user vars because we can write our own home and username resolution:
the user home directoy can be resolved with:
- $HOME (if set)
- $HOME/${getpwent()->pw_name}
- $TZ_SYS_HOME/$USER (if $USER is set)
- $TZ_SYS_HOME/${getpwent()->pw_name}
- ${getpwent()->pw_dir}/${getpwent()->pw_name}
The last one is the most secure, but this supposes that the users will be
created in the appropriate dir (the user creation module MUST use the tizen-env
config file and the TZ_SYS_HOME definition, or be compiled with tizen-env-devel
!).
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