The preStart snippets (graphite, carbon) try to create directories under
/var/db/. That currently fails because the code is run as user
"graphite". Fix by setting "PermissionsStartOnly = true" so that the
preStart stuff is run as 'root'.
Further:
* graphite-web-0.9.12/bin/build-index.sh needs perl, so add it to PATH.
* Now that preStart runs as root, we must wait with "chown graphite"
until we're done creating files/directories.
* Drop needless check for root (uid 0) before running chown.
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
(systemd service descriptions that is, not service descriptions in "man
configuration.nix".)
Capitalizing each word in the description seems to be the accepted
standard.
Also shorten these descriptions:
* "Munin node, the agent process" => "Munin Node"
* "Planet Venus, an awesome ‘river of news’ feed reader" => "Planet Venus Feed Reader"
Twisted provides option to log with syslog, this enables nicer logging.
Imagine what happens in a case of exception. If logs are written to stdout,
traceback won't be merged thus giving ugly logs. This commit fixes that.
This is also one of the official ways of starting carbon, so no worries.
