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.
Closes#997.
* topic/robin/sqlite-merge: (25 commits)
Fix to make sqlite test consistent, and updating coverage baselines
Avoid a CMake warning about 3rdparty looking like a number.
Fixing linker error.
and there is no has-reader.
make sqlite3 executable required and add test-cases for errors
Renaming src/external -> src/3rdparty
fix a few small rough edges (mostly comments that do no longer apply)
fix bug in input-manager regarding enums that a writer reads without 0-terminating the string
actually make sqlite work again (tests passed because the writer was not actually defined because of the define.)
add sqlite distribution.
fix warnings, update baselines, handle rotation
add sqlite tests and fix small vector/set escaping bugs
fix small bug with vectors and sets.
make work with newer AsciiFormatter.
start adding a different text for empty records for the sqlite writer.
no, you will never guess from where I copied this file...
make sqlite support more or less work for logging and input
make sqlite-writer more stable.
make it compile with new version of AsciiInputOutput
and adapt to AsciiInputOutput - seems to work...
...
Conflicts:
scripts/base/frameworks/input/__load__.bro
src/CMakeLists.txt
src/input.bif
src/input/Manager.cc
src/main.cc
src/types.bif
testing/btest/Baseline/coverage.bare-load-baseline/canonified_loaded_scripts.log
testing/btest/Baseline/coverage.default-load-baseline/canonified_loaded_scripts.log
Sadly there also seems to be another deadlock issue which I am currently
not really able to figure out - on shutdown sometimes (too often) the main
thread + all sqlite threads wait for semaphores or mutexes.
The only snag is... with the default output format of the log-file writer, the input reader cannot tell if a table or set is empty or uninitialized (both cases use the same character by default). In this case, by default it is assumed that the field/vector is uninitalized.
