Hi,
I wrote down the thoughts I had in mind when developing the conf.d patch which got integrated in vdr 2.1.7.
Also I like to give some advice to distributors how I think, this feature should be used. If we can agree on a consistent naming and file-layout all users can profit.
At the end there's an RFC for an interface to a not-yet-written tool "vdrctl" for managing the args-conf-files.
Any comments and improvements are welcome.
Regards, Lars.
Using ARGSDIR -------------
The target of the "conf.d patch" is to simplify the start of vdr esp. with the newer init systems Upstart and systemd. These systems expect a single "exec" line to start a daemon. Additionally they provide mechanism for monitoring, restart on failure and controlled stopping on shutdown with defined dependencies.
In the past vdr needed a long list of options, every plugin had to be mentioned, and if a plugin also needs options, the commandline gets longer and confusing. There's also the runvdr template for controlling the start and restart of vdr, which has to be adjusted to your personally needs, which makes it difficult for distributions to update these script. That is why the different distributions developed their own starting mechanisms and reading options for vdr and plugins from different files. Now with all options separated from the starting script, it will be easier to share the same configuration on different platforms and improve helping each other in adding the right options to your vdr installation.
By default, the conf-files are located at /etc/vdr/conf.d, of course this can be changed via the Make.config, but not on the commandline itself, because a vdr with an option won't read the options from the conf-files to maintain backwards compatibility, so you can't choose a directory on demand. But what you can do, is to symlink different files to your conf.d-directory or even symlink the whole directory, to adjust your configuration. Additionally the directory can be retrieved by using "pkg-config --variable=argsdir vdr".
To check the current configuration the vdr would use if you start it right now, you can call "vdr --showargs".
Here's an example from my installation:
$ vdr --showargs --video=/srv/vdr/video.00 --config=/var/lib/vdr --lib=/usr/lib/vdr/plugins --record=/usr/lib/vdr/vdr-recordingaction --shutdown=/usr/lib/vdr/vdr-shutdown.wrapper --epgfile=/var/cache/vdr/epg.data --user=vdr --grab=/tmp --port=6419 --resdir=/usr/share/vdr --cachedir=/var/cache/vdr --dirnames=,,1 --watchdog=0 --userdump --plugin=epg2vdr --plugin=channellists --plugin=sundtek --plugin=avahi4vdr --plugin=dbus2vdr --shutdown-hooks=/usr/share/vdr/shutdown-hooks --shutdown-hooks-wrapper=/usr/share/vdr-plugin-dbus2vdr/shutdown-wrapper --upstart --plugin=epgsearch -f /usr/bin/svdrpsend --plugin=live --port=8008 --ip=0.0.0.0 --log=INFO --epgimages=/var/cache/vdr/epgimages --plugin=menuorg --plugin=vnsiserver -t 10 --plugin=streamdev-server --plugin=softhddevice -D --plugin=epgsearchonly --plugin=recsearch --plugin=restfulapi --port=8002 --ip=0.0.0.0 --epgimages=/var/cache/vdr/epgimages --channellogos=/usr/share/vdr-channellogos --webapp=/var/lib/vdr/plugins/restfulapi/webapp --plugin=quickepgsearch --plugin=conflictcheckonly --plugin=skindesigner --epgimages=/var/cache/vdr/epgimages --plugin=dynamite
The corresponding conf file looks like:
#### /etc/vdr/conf.d/vdr.conf [vdr] --video=/srv/vdr/video.00 --config=/var/lib/vdr --lib=/usr/lib/vdr/plugins --record=/usr/lib/vdr/vdr-recordingaction --shutdown=/usr/lib/vdr/vdr-shutdown.wrapper --epgfile=/var/cache/vdr/epg.data --user=vdr --grab=/tmp --port=6419 --resdir=/usr/share/vdr --cachedir=/var/cache/vdr --dirnames=,,1 --watchdog=0 --userdump
[epg2vdr]
[channellists]
[sundtek]
[avahi4vdr]
[dbus2vdr] --shutdown-hooks=/usr/share/vdr/shutdown-hooks --shutdown-hooks-wrapper=/usr/share/vdr-plugin-dbus2vdr/shutdown-wrapper --upstart
[epgsearch] -f /usr/bin/svdrpsend
[live] --port=8008 --ip=0.0.0.0 --log=INFO --epgimages=/var/cache/vdr/epgimages
[menuorg]
[vnsiserver] -t 10
[streamdev-server]
[softhddevice] -D
[epgsearchonly]
[recsearch]
[restfulapi] --port=8002 --ip=0.0.0.0 --epgimages=/var/cache/vdr/epgimages --channellogos=/usr/share/vdr-channellogos --webapp=/var/lib/vdr/plugins/restfulapi/webapp
[quickepgsearch]
[conflictcheckonly]
[skindesigner] --epgimages=/var/cache/vdr/epgimages
[dynamite] #### end of /etc/vdr/conf.d/vdr.conf
"showargs" takes as an optional parameter a directory. It will read all *.conf files from the given directory and prints the corresponding configuration. This is helpful if you have various configurations and want to compare them.
Distributors ------------
In the example above I use a single conf file. For a self maintained installation this may be usable, but from the perspective of a distributor the configuration should be splitted into one file per plugin and a file for vdr itself. With a package manager in mind, it has been approved, when you install a default configuration file with a plugin package, this file should be placed at /etc/vdr/conf.avail. To activate the plugin, a symlink can be placed at the conf.d directory. And with removing the symlink a plugin can easily be deactivated without removing the whole package.
Keep in mind that even if a plugin doesn't need any arguments, a file with "[pluginname]" is needed, so the plugin is loaded. Just like adding "-Ppluginname" to vdr's commandline.
Mostly the order of the plugins is not important, but for those small usecases, where you want to force a loading order, the following should be used:
- The file with the options for vdr-core should actually be called "00-vdr.conf" so it will be read first. - An additional file "01-vdr-dbg.conf" can be used for special debugging options like "--userdump" etc. - Files for plugins which like to be loaded first, should be named "10-pluginname.conf". - Files for plugins which like to be loaded last, should be named "90-pluginname.conf". - Files for all other plugins with independend order should be named "50-pluginname.conf".
vdrctl ------
What I like to see in the future is a tool "vdrctl" which will add/remove those symlinks or list the available or actived plugins etc. I would like to only specify an API for this tool, so every distribution can develop its own tool. Of course there can be a reference implementation like a simple shell-, Perl- or Python-script.
In the following ARGSDIR is the configured conf.d path in your Make.config (or read by pkg-config). AVAILDIR is ARGSDIR/../conf.avail if not another directory is given. Filenames are the names of the files without their directory.
Usage: vdrctl [global options] command [command options]
Global options: --argsdir=<directory> read files from <directory> instead of ARGSDIR --availdir=<directory> read files from <directory> instead of ARGSDIR/../conf.avail
Commands:
list (without options) print a sorted list of all configuration files from AVAILDIR
--enabled print a sorted list of all configuration files from ARGSDIR
--disabled print a sorted list of all configuration files from AVAILDIR which are not symlinked to ARGSDIR
enable <filename> create a symlink in ARGSDIR pointing to the file in AVAILDIR
disable <filename> remove the symlink in ARGSDIR
edit <filename> start an editor so the user can add/remove options to the file in AVAILDIR