The configuration framework consists of three mostly distinct parts:
* option variables
* the config reader
* the script level framework
I will describe the three elements in the following.
Internally, this commit also performs a range of changes to the Input
manager; it marks a lot of functions as const and introduces a new
ValueToVal method (which could in theory replace the already existing
one - it is a bit more powerful).
This also changes SerialTypes to have a subtype for Values, just as
Fields already have it; I think it was mostly an oversight that this was
not introduced from the beginning. This should not necessitate any code
changes for people already using SerialTypes.
option variable
===============
The option keyword allows variables to be specified as run-tine options.
Such variables cannot be changed using normal assignments. Instead, they
can be changed using Option::set. It is possible to "subscribe" to
options and be notified when an option value changes.
Change handlers can also change values before they are applied; this
gives them the opportunity to reject changes. Priorities can be
specified if there are several handlers for one option.
Example script:
option testbool: bool = T;
function option_changed(ID: string, new_value: bool): bool
{
print fmt("Value of %s changed from %s to %s", ID, testbool, new_value);
return new_value;
}
event bro_init()
{
print "Old value", testbool;
Option::set_change_handler("testbool", option_changed);
Option::set("testbool", F);
print "New value", testbool;
}
config reader
=============
The config reader provides a way to read configuration files back into
Bro. Most importantly it automatically converts values to the correct
types. This is important because it is at least inconvenient (and
sometimes near impossible) to perform the necessary type conversions in
Bro scripts themselves. This is especially true for sets/vectors.
Configuration generally look like this:
[option name][tab/spaces][new variable value]
so, for example:
testaddr 2607:f8b0:4005:801::200e
testinterval 60
testtime 1507321987
test_set a b c d erdbeerschnitzel
The reader uses the option name to look up the type that variable has in
the Bro core and automatically converts the value to the correct type.
Example script use:
type Idx: record {
option_name: string;
};
type Val: record {
option_val: string;
};
global currconfig: table[string] of string = table();
event InputConfig::new_value(name: string, source: string, id: string, value: any)
{
print id, value;
}
event bro_init()
{
Input::add_table([$reader=Input::READER_CONFIG, $source="../configfile", $name="configuration", $idx=Idx, $val=Val, $destination=currconfig, $want_record=F]);
}
Script-level config framework
=============================
The script-level framework ties these two features together and makes
them a bit more convenient to use. Configuration files can simply be
specified by placing them into Config::config_files. The framework also
creates a config.log that shows all value changes that took place.
Usage example:
redef Config::config_files += {configfile};
export {
option testbool : bool = F;
}
The file is now monitored for changes; when a change occurs the
respective option values are automatically updated and the value change
is written to config.log.
Great work, and great documentation!
I'm getting one test failure with
scripts.base.frameworks.netcontrol.catch-and-release-cluster Going
ahead and commiting, Jenkins will show the details I assume.
BIT-1584 #merged
* origin/topic/johanna/netcontrol-improvements:
SMTP does not need to pull in the notice framework.
Write NetControl framework documentation.
Use NetControl for ACTION_DROP of notice framework.
NetControl: slightly update catch and release logging
NetControl: fix several small logging issues
NetControl: more catch and release logging and cluster fix
NetControl: rewrite catch and release and small fixes.
NetControl: find_rules_subnet works in cluster mode
NetControl: fix acld whitelist command
NetControl: add rule exists as state besides added and failure.
NetControl: Suppress duplicate "plugin activated" messages.
NetControl: make new broker plugin options accessible
NetControl: add predicates to broker plugin
* origin/topic/jdopheid/BIT-1242:
Improved the log file reference documentation
Added missing log files prof, stderr, stdout
Add a test that detects changes in the list of all Bro log files
Broke down logs into grouped sections based on use & origin
Adding deatils for modbus_register_change.log
More updates to log files page: descriptions
Changing name of file
New page for List of Log files, linked to script-reference
Very nice. I've reorganized slightly more, mostly to shrink down the
"other" category: moved some of that into "Detection" and "Files" (the
latter is small, but will hopefully grow).
BIT-1242 #merged
Reorganized the log file reference documentation, improved some of the
descriptions, and corrected a typo in a log filename. Also removed
non-ascii characters that somehow got in the text.
