profile

• infos = Information about the profile plugin is in keys below
• infos/author = Thomas Waser thomas.waser@libelektra.org
• infos/licence = BSD
• infos/needs =
• infos/provides =
• infos/recommends =
• infos/placements = postgetstorage presetstorage
• infos/status = libc nodep global preview unfinished
• infos/metadata =
• infos/description = helps switching between configuration profiles

Usage

Following the elektra keyname convention application configurations are stored under /sw/org/myapp/# and /sw/org/myapp/#0/currentis the profile to be used. The profile plugin provides an easy way to switch configuration profiles.

The key /sw/org/myapp/#0/profile defines what profile should be used as current, e.g. /sw/org/myapp/#0/profile = myprofile. If a key /sw/org/myapp/#0/myprofile/key is found and no key /sw/org/myapp/#0/current/key exists an override key will be created linking /sw/org/myapp/#0/currrent/key to /sw/org/myapp/#0/myapp/key If neither /sw/org/myapp/#0/current/key nor /sw/org/myapp/#0/myprofile/key is found, but /sw/org/myapp/#0/%/key, /sw/org/myapp/#0/current/key will be linked to /sw/org/myapp/#0/%/key.

So a cascading lookup will automatically implement following preferences (next to the namespace preferences):

1. Usage of key in current
2. Usage of key in the profile set with profile
3. Usage of key in the % fallback profile

Example

Suppose we have the configuration file profile.ini in ~/.config:

cat profile.ini
#> []
#> profile = myprofile
#>
#> [current]
#> key2 = will win
#>
#> [myprofile]
#> key1 = test1
#> key2 = test2
#>
#> [%]
#> key2 = failed?
#> key3 = test3

Then we simply mount it without the profile plugin:

kdb mount profile.ini /sw/org/myapp/#0 ini

But we have to make sure that the profile plugin is mounted globally:

kdb global-mount profile

Then we can access /sw/org/myapp/#0 in a profile-aware way:

kdb ls /sw
#> spec/sw/org/myapp/#0/current/key1
#> spec/sw/org/myapp/#0/current/key3
#> user/sw/org/myapp/#0
#> user/sw/org/myapp/#0/%
#> user/sw/org/myapp/#0/%/key2
#> user/sw/org/myapp/#0/%/key3
#> user/sw/org/myapp/#0/current
#> user/sw/org/myapp/#0/current/key2
#> user/sw/org/myapp/#0/profile
#> user/sw/org/myapp/#0/myprofile
#> user/sw/org/myapp/#0/myprofile/key1
#> user/sw/org/myapp/#0/myprofile/key2

As we can see with the -v option, we will fetch keys from our myprofile even though we request current:

kdb get -v /sw/org/myapp/#0/current/key1
#> got 25 keys
#> searching spec/sw/org/myapp/#0/current/key1, found: spec/sw/org/myapp/#0/current/key1, options: KDB_O_CALLBACK
#> The resulting keyname is user/sw/org/myapp/#0/myprofile/key1
#> test1

To switch profile we simply have to set one key:

kdb set user/sw/org/myapp/#0/profile newprofile

Usually, this will be done via commandline by setting proc/sw/org/myapp/#0/profile.