This addresses the need for a central hook on any log write, which
wasn't previously doable without a lot of effort. The log manager
invokes the new Log::log_stream_policy hook prior to any filter-specific
hooks. Like filter-level hooks, it may veto a log write. Even when
it does, filter-level hooks still get invoked, but cannot "un-veto".
Includes test cases.
Update the logging framework tests: since hooks operate
by name, they cannot be anonymous. I'm also dropping the &optional
attribute from the status field, since here know that the values are
actually defined, and access to an optional status field should
normally be guarded by the existence test operator.
Also includes baseline update for plugins.hooks, which picks up the
fact that the pred record field is now gone.
This adds a "policy" hook into the logging framework's streams and
filters to replace the existing log filter predicates. The hook
signature is as follows:
hook(rec: any, id: Log::ID, filter: Log::Filter);
The logging manager invokes hooks on each log record. Hooks can veto
log records via a break, and modify them if necessary. Log filters
inherit the stream-level hook, but can override or remove the hook as
needed.
The distribution's existing log streams now come with pre-defined
hooks that users can add handlers to. Their name is standardized as
"log_policy" by convention, with additional suffixes when a module
provides multiple streams. The following adds a handler to the Conn
module's default log policy hook:
hook Conn::log_policy(rec: Conn::Info, id: Log::ID, filter: Log::Filter)
{
if ( some_veto_reason(rec) )
break;
}
By default, this handler will get invoked for any log filter
associated with the Conn::LOG stream.
The existing predicates are deprecated for removal in 4.1 but continue
to work.
These may be redefined to customize log rotation path prefixes,
including use of a directory. File extensions are still up to
individual log writers to add themselves during the actual rotation.
These new also allow for some simplication to the default
ASCII postprocessor function: it eliminates the need for it doing an
extra/awkward rename() operation that only changes the timestamp format.
This also teaches the supervisor framework to use these new options
to rotate ascii logs into a log-queue/ directory with a specific
file name format (intended for an external archiver process to
monitor separately).
Adjustments during merge:
- kept the UNKNOWN Log::ID as placeholder value
- changed the coverage.find-bro-logs test to check for arbitrary $path
field values instead of just string literals
- don't force EnumVal to unsigned integer since the relevant union member
is the signed integer and added the relevant enum values/types to
.bif files for easier access
- compare FILE* versus file name to check for stdout equality (don't
think it matters much, just a bit more efficient)
- minor whitespace/style tweaks
* origin/topic/dev/print-to-log:
Added a non boolean configuration and other changes as suggested by Jon
Allow Print Statements to be redirected to a Log# This is a combination of 3 commits.
* All "Broxygen" usages have been replaced in
code, documentation, filenames, etc.
* Sphinx roles/directives like ":bro:see" are now ":zeek:see"
* The "--broxygen" command-line option is now "--zeexygen"
