This commit factors out several common ZEDLET code blocks into
zed-functions.sh. This shortens the length of the scripts, thereby
(hopefully) making them easier to understand and maintain.
In addition, this commit revamps the coding style used by the
scripts to be more consistent and (again, hopefully) maintainable.
It now mostly follows the Google Shell Style Guide. I've tried to
assimilate the following resources:
Google Shell Style Guide
https://google-styleguide.googlecode.com/svn/trunk/shell.xml
Dash as /bin/sh
https://wiki.ubuntu.com/DashAsBinSh
Filenames and Pathnames in Shell: How to do it Correctly
http://www.dwheeler.com/essays/filenames-in-shell.html
Common shell script mistakes
http://www.pixelbeat.org/programming/shell_script_mistakes.html
Finally, this commit updates the exit codes used by the ZEDLETs to be
more consistent with one another.
All scripts run cleanly through ShellCheck <http://www.shellcheck.net/>.
All scripts have been tested on bash and dash.
Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
The executables invoked by the ZED in response to a given zevent
have been generically referred to as "scripts". By convention,
these scripts have aimed to be /bin/sh compatible for reasons of
portability and comprehensibility. However, the ZED only requires
they be executable and (ideally) capable of reading environment
variables. As such, these scripts are now referred to as ZEDLETs
(ZFS Event Daemon Linkage for Executable Tasks).
Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2735
zed monitors ZFS events. When a zevent is posted, zed will run any
scripts that have been enabled for the corresponding zevent class.
Multiple scripts may be invoked for a given zevent. The zevent
nvpairs are passed to the scripts as environment variables.
Events are processed synchronously by the single thread, and there is
no maximum timeout for script execution. Consequently, a misbehaving
script can delay (or forever block) the processing of subsequent
zevents. Plans are to address this in future commits.
Initial scripts have been developed to log events to syslog
and send email in response to checksum/data/io errors and
resilver.finish/scrub.finish events. By default, email will only
be sent if the ZED_EMAIL variable is configured in zed.rc (which is
serving as a config file of sorts until a proper configuration file
is implemented).
Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2
