fix bug that allowed forwarded logs to be output from the logger built via env vars
[scpubgit/Object-Remote.git] / lib / Object / Remote /
5e2b2229 1package Object::Remote::Logging;
4e446335 3use Moo;
4use Scalar::Util qw(blessed);
5use Object::Remote::Logging::Logger;
f4a85080 6use Exporter::Declare;
663fb34f 7use Carp qw(carp croak);
5e2b2229 8
4e446335 9extends 'Log::Contextual';
5e2b2229 10
663fb34f 11exports(qw( ____ router arg_levels ));
f4a85080 12
4e446335 13sub router {
c0b2df05 14 our $Router_Instance ||= do {
15 require Object::Remote::Logging::Router;
16 Object::Remote::Logging::Router->new;
17 }
4e446335 18}
5e2b2229 19
9de32e1d 20#log level descriptions
21#info - standard log level - normal program output for the end user
22#warn - output for program that is executing quietly
23#error - output for program that is running more quietly
24#fatal - it is not possible to continue execution; this level is as quiet as is possible
25#verbose - output for program executing verbosely (-v)
26#debug - output for program running more verbosely (-v -v)
27#trace - output for program running extremely verbosely (-v -v -v)
4e446335 28sub arg_levels {
9de32e1d 29 #the order of the log levels is significant with the
30 #most verbose level being first in the list and the
31 #most quiet as the last item
32 return [qw( trace debug verbose info warn error fatal )];
4a9fa1a5 33}
5e2b2229 34
663fb34f 35sub before_import {
36 my ($class, $importer, $spec) = @_;
37 my $router = $class->router;
c2a69537 38 our $DID_INIT;
663fb34f 39
c2a69537 40 unless($DID_INIT) {
41 $DID_INIT = 1;
42 init_logging();
43 }
663fb34f 45 $class->SUPER::before_import($importer, $spec);
663fb34f 46}
ae198201 48sub _parse_selections {
8f43bcd9 49 my ($selections_string) = @_;
50 my %log_ok;
ae198201 51
8f43bcd9 52 #example string:
53 #" * -Object::Remote::Logging Foo::Bar::Baz "
54 foreach(split(/\s+/, $selections_string)) {
55 next if $_ eq '';
56 if ($_ eq '*') {
57 $log_ok{$_} = 1;
58 } elsif (s/^-//) {
59 $log_ok{$_} = 0;
60 } else {
61 $log_ok{$_} = 1;
ae198201 62 }
8f43bcd9 63 }
ae198201 64
8f43bcd9 65 return %log_ok;
ae198201 66}
4e446335 68#this is invoked on all nodes
4a9fa1a5 69sub init_logging {
c0b2df05 70 my $level = $ENV{OBJECT_REMOTE_LOG_LEVEL};
0fe333eb 71 my $format = $ENV{OBJECT_REMOTE_LOG_FORMAT};
eb49c7df 72 my $selections = $ENV{OBJECT_REMOTE_LOG_SELECTIONS};
abef6e5b 73 my $test_logging = $ENV{OBJECT_REMOTE_TEST_LOGGER};
eb49c7df 74 my %controller_should_log;
09f583a7 75
78 }
abef6e5b 79
80 if ($test_logging) {
81 require Object::Remote::Logging::TestLogger;
8c352906 82 router->connect(Object::Remote::Logging::TestLogger->new(
abef6e5b 83 min_level => 'trace', max_level => 'error',
84 level_names => Object::Remote::Logging->arg_levels(),
85 ));
86 }
5cd5276e 87
f1d70835 88 {
89 no warnings 'once';
90 if (defined $Object::Remote::FatNode::REMOTE_NODE) {
91 #the connection id for the remote node comes in later
92 #as the controlling node inits remote logging
93 router()->_remote_metadata({ connection_id => undef });
94 }
95 }
f6a52399 97 return unless defined $level && $level ne '';
99 $format = "[%l %r] %s" unless defined $format;
100 $selections = __PACKAGE__ unless defined $selections;
101 %controller_should_log = _parse_selections($selections);
c0b2df05 103 my $logger = Object::Remote::Logging::Logger->new(
0fe333eb 104 min_level => lc($level), format => $format,
c0b2df05 105 level_names => Object::Remote::Logging::arg_levels(),
106 );
c0b2df05 108 router()->connect(sub {
eb49c7df 109 my $controller = $_[1]->{controller};
ae198201 110 my $will_log = $controller_should_log{$controller};
112 $will_log = $controller_should_log{'*'} unless defined $will_log;
114 return unless $will_log;
c0b2df05 115 #skip things from remote hosts because they log to STDERR
116 #when OBJECT_REMOTE_LOG_LEVEL is in effect
a577b953 117 return if $_[1]->{remote}->{object_remote};
c0b2df05 118 $logger
119 });
4a9fa1a5 120}
4e446335 122#this is invoked by the controlling node
123#on the remote nodes
f1d70835 124sub init_remote_logging {
4e446335 125 my ($self, %controller_info) = @_;
f1d70835 127 router()->_remote_metadata(\%controller_info);
466ee2c4 128 router()->_forward_destination($controller_info{router}) if $ENV{OBJECT_REMOTE_LOG_FORWARDING};
4a9fa1a5 129}
5e2b2229 130
455d031c 132
d672a9bf 133__END__
135=head1 NAME
137Object::Remote::Logging - Logging subsystem for Object::Remote
139=head1 SYNOPSIS
b8176a97 141 use Object::Remote::Logging qw( :log :dlog arg_levels router );
d672a9bf 142
143 @levels = qw( trace debug verbose info warn error fatal );
144 @levels = arg_levels(); #same result
146 $ENV{OBJECT_REMOTE_LOG_LEVEL} = 'trace'; #or other level name
147 $ENV{OBJECT_REMOTE_LOG_FORMAT} = '%l %t: %p::%m %s'; #and more
d672a9bf 148 $ENV{OBJECT_REMOTE_LOG_SELECTIONS} = 'Object::Remote::Logging Some::Other::Subclass';
ae198201 149 $ENV{OBJECT_REMOTE_LOG_SELECTIONS} = '* -Object::Remote::Logging';
09f583a7 150 $ENV{OBJECT_REMOTE_LOG_FORWARDING} = 0; #default 1
d672a9bf 151
152 log_info { 'Trace log event' };
153 Dlog_verbose { "Debug event with Data::Dumper::Concise: $_" } { foo => 'bar' };
d672a9bf 154
157This is the logging framework for Object::Remote implemented as a subclass of
158L<Log::Contextual> with a slightly incompatible API. This system allows
159developers using Object::Remote and end users of that software to control
160Object::Remote logging so operation can be tracked if needed. This is also
161the API used to generate log messages inside the Object::Remote source code.
163The rest of the logging system comes from L<Object::Remote::Logging::Logger>
164which implements log rendering and output and L<Object::Remote::Logging::Router>
165which delivers log events to the loggers.
455d031c 167=head1 USAGE
169Object::Remote logging is not enabled by default. If you need to immediately start
170debugging set the OBJECT_REMOTE_LOG_LEVEL environment variable to either 'trace'
171or 'debug'. This will enable logging to STDERR on the local and all remote Perl
172interpreters. By default STDERR for all remote interpreters is passed through
173unmodified so this is sufficient to receive logs generated anywhere Object::Remote
174is running.
176Every time the local interpreter creates a new Object::Remote::Connection the connection
177is given an id that is unique to that connection on the local interpreter. The connection
178id and other metadata is available in the log output via a log format string that can
179be set via the OBJECT_REMOTE_LOG_FORMAT environment variable. The format string and
180available metadata is documented in L<Object::Remote::Logging::Logger>. Setting this
181environment variable on the local interpreter will cause it to be propagated to the
182remote interpreter so all logs will be formated the same way.
184This class is designed so any module can create their own logging sub-class using it.
f21127fd 185With out any additional configuration the consumers of this logging class will
186automatically be enabled via OBJECT_REMOTE_LOG_LEVEL and formated with
187OBJECT_REMOTE_LOG_FORMAT but those additional log messages are not sent to STDERR.
188By setting the OBJECT_REMOTE_LOG_SELECTIONS environment variable to a list of
189class names seperated by spaces then logs generated by packages that use those classes
ae198201 190will be sent to STDERR. If the asterisk character (*) is used in the place of a class
191name then all class names will be selected by default instead of ignored. An individual
192class name can be turned off by prefixing the name with a hypen character (-). This is
193also a configuration item that is forwarded to the remote interpreters so all logging
194is consistent.
455d031c 195
196Regardless of OBJECT_REMOTE_LOG_LEVEL the logging system is still active and loggers
197can access the stream of log messages to format and output them. Internally
198OBJECT_REMOTE_LOG_LEVEL causes an L<Object::Remote::Logging::Logger> to be built
199and connected to the L<Object::Remote::Logging::Router> instance. It is also possible
200to manually build a logger instance and connect it to the router. See the documentation
f21127fd 201for the logger and router classes.
455d031c 202
203The logging system also supports a method of forwarding log messages from remote
204interpreters to the local interpreter. Forwarded log messages are generated in the
205remote interpreter and the logger for the message is invoked in the local interpreter.
206Sub-classes of Object::Remote::Logging will have log messages forwarded automatically.
207Loggers receive forwarded log messages exactly the same way as non-forwarded messages
208except a forwarded message includes extra metadata about the remote interpreter. Log
09f583a7 209forwarding is enabled by default but comes with a performance hit; to disable it set the
210OBJECT_REMOTE_LOG_FORWARDING environment variable to 0. See L<Object::Remote::Logging::Router>.
455d031c 211
214=over 4
216=item arg_levels
218Returns an array reference that contains the ordered list of level names
219with the lowest log level first and the highest log level last.
221=item router
223Returns the instance of L<Object::Remote::Logging::Router> that is in use. The router
224instance is used in combination with L<Object::Remote::Logging::Logger> objects to
225select then render and output log messages.
227=item log_<level> and Dlog_<level>
229These methods come direct from L<Log::Contextual>; see that documentation for a
230complete reference. For each of the log level names there are subroutines with the log_
231and Dlog_ prefix that will generate the log message. The first argument is a code block
232that returns the log message contents and the optional further arguments are both passed
233to the block as the argument list and returned from the log method as a list.
235 log_trace { "A fine log message $_[0] " } 'if I do say so myself';
455d031c 236 %hash = Dlog_trace { "Very handy: $_" } ( foo => 'bar' );
d672a9bf 237
238=item logS_<level> and DlogS_<level>
240Works just like log_ and Dlog_ except returns only the first argument as a scalar value.
302ecfbf 242 my $beverage = logS_info { "Customer ordered $_[0]" } 'Coffee';
d672a9bf 243
d672a9bf 244=back
246=head1 LEVEL NAMES
293fb1ee 248Object::Remote uses an ordered list of log level names with the lowest level
249first and the highest level last. The list of level names can be accessed via
d672a9bf 250the arg_levels method which is exportable to the consumer of this class. The log
251level names are:
253=over 4
255=item trace
257As much information about operation as possible including multiple line dumps of
258large content. Tripple verbose operation (-v -v -v).
260=item debug
262Messages about operations that could hang as well as internal state changes,
263results from method invocations, and information useful when looking for faults.
264Double verbose operation (-v -v).
266=item verbose
268Additional optional messages to the user that can be enabled at their will. Single
269verbose operation (-v).
271=item info
273Messages from normal operation that are intended to be displayed to the end
274user if quiet operation is not indicated and more verbose operation is not
275in effect.
277=item warn
279Something wasn't supposed to happen but did. Operation was not impacted but
280otherwise the event is noteworthy. Single quiet operation (-q).
282=item error
284Something went wrong. Operation of the system may continue but some operation
285has most definitely failed. Double quiet operation (-q -q).
287=item fatal
289Something went wrong and recovery is not possible. The system should stop operating
290as soon as possible. Tripple quiet operation (-q -q -q).