Monolog - Logging for PHP 5.3+
Monolog sends your logs to files, sockets, inboxes, databases and various
web services. See the complete list of handlers below. Special handlers
allow you to build advanced logging strategies.
This library implements the PSR-3
interface that you can type-hint against in your own libraries to keep
a maximum of interoperability. You can also use it in your applications to
make sure you can always use another compatible logger at a later time.
As of 1.11.0 Monolog public APIs will also accept PSR-3 log levels.
Internally Monolog still uses its own level scheme since it predates PSR-3.
Usage
<?php
use Monolog\Logger;
use Monolog\Handler\StreamHandler;
// create a log channel
$log = new Logger('name');
$log->pushHandler(new StreamHandler('path/to/your.log', Logger::WARNING));
// add records to the log
$log->addWarning('Foo');
$log->addError('Bar');
Core Concepts
Every Logger
instance has a channel (name) and a stack of handlers. Whenever
you add a record to the logger, it traverses the handler stack. Each handler
decides whether it handled fully the record, and if so, the propagation of the
record ends there.
This allows for flexible logging setups, for example having a StreamHandler
at
the bottom of the stack that will log anything to disk, and on top of that add
a MailHandler
that will send emails only when an error message is logged.
Handlers also have a $bubble
property which defines whether they block the
record or not if they handled it. In this example, setting the MailHandler
's
$bubble
argument to false means that records handled by the MailHandler
will
not propagate to the StreamHandler
anymore.
You can create many Logger
s, each defining a channel (e.g.: db, request,
router, ..) and each of them combining various handlers, which can be shared
or not. The channel is reflected in the logs and allows you to easily see or
filter records.
Each Handler also has a Formatter, a default one with settings that make sense
will be created if you don't set one. The formatters normalize and format
incoming records so that they can be used by the handlers to output useful
information.
Custom severity levels are not available. Only the eight
RFC 5424 levels (debug, info, notice,
warning, error, critical, alert, emergency) are present for basic filtering
purposes, but for sorting and other use cases that would require
flexibility, you should add Processors to the Logger that can add extra
information (tags, user ip, ..) to the records before they are handled.
Log Levels
Monolog supports the logging levels described by RFC 5424.
DEBUG (100): Detailed debug information.
INFO (200): Interesting events. Examples: User logs in, SQL logs.
NOTICE (250): Normal but significant events.
WARNING (300): Exceptional occurrences that are not errors. Examples:
Use of deprecated APIs, poor use of an API, undesirable things that are not
necessarily wrong.
ERROR (400): Runtime errors that do not require immediate action but
should typically be logged and monitored.
CRITICAL (500): Critical conditions. Example: Application component
unavailable, unexpected exception.
ALERT (550): Action must be taken immediately. Example: Entire website
down, database unavailable, etc. This should trigger the SMS alerts and wake
you up.
EMERGENCY (600): Emergency: system is unusable.
Docs
See the doc
directory for more detailed documentation.
The following is only a list of all parts that come with Monolog.
Handlers
Log to files and syslog
- StreamHandler: Logs records into any PHP stream, use this for log files.
- RotatingFileHandler: Logs records to a file and creates one logfile per day.
It will also delete files older than
$maxFiles
. You should use
logrotate for high profile
setups though, this is just meant as a quick and dirty solution.
- SyslogHandler: Logs records to the syslog.
- ErrorLogHandler: Logs records to PHP's
error_log()
function.
Send alerts and emails
- NativeMailerHandler: Sends emails using PHP's
mail()
function.
- SwiftMailerHandler: Sends emails using a
Swift_Mailer
instance.
- PushoverHandler: Sends mobile notifications via the Pushover API.
- HipChatHandler: Logs records to a HipChat chat room using its API.
- FlowdockHandler: Logs records to a Flowdock account.
- SlackHandler: Logs records to a Slack account.
- MandrillHandler: Sends emails via the Mandrill API using a
Swift_Message
instance.
- FleepHookHandler: Logs records to a Fleep conversation using Webhooks.
Log specific servers and networked logging
- SocketHandler: Logs records to sockets, use this
for UNIX and TCP sockets. See an example.
- AmqpHandler: Logs records to an amqp compatible
server. Requires the php-amqp extension (1.0+).
- GelfHandler: Logs records to a Graylog2 server.
- CubeHandler: Logs records to a Cube server.
- RavenHandler: Logs records to a Sentry server using
raven.
- ZendMonitorHandler: Logs records to the Zend Monitor present in Zend Server.
- NewRelicHandler: Logs records to a NewRelic application.
- LogglyHandler: Logs records to a Loggly account.
- RollbarHandler: Logs records to a Rollbar account.
- SyslogUdpHandler: Logs records to a remote Syslogd server.
- LogEntriesHandler: Logs records to a LogEntries account.
Logging in development
- FirePHPHandler: Handler for FirePHP, providing
inline
console
messages within FireBug.
- ChromePHPHandler: Handler for ChromePHP, providing
inline
console
messages within Chrome.
- BrowserConsoleHandler: Handler to send logs to browser's Javascript
console
with
no browser extension required. Most browsers supporting console
API are supported.
Log to databases
- RedisHandler: Logs records to a redis server.
- MongoDBHandler: Handler to write records in MongoDB via a
Mongo extension connection.
- CouchDBHandler: Logs records to a CouchDB server.
- DoctrineCouchDBHandler: Logs records to a CouchDB server via the Doctrine CouchDB ODM.
- ElasticSearchHandler: Logs records to an Elastic Search server.
- DynamoDbHandler: Logs records to a DynamoDB table with the AWS SDK.
Wrappers / Special Handlers
- FingersCrossedHandler: A very interesting wrapper. It takes a logger as
parameter and will accumulate log records of all levels until a record
exceeds the defined severity level. At which point it delivers all records,
including those of lower severity, to the handler it wraps. This means that
until an error actually happens you will not see anything in your logs, but
when it happens you will have the full information, including debug and info
records. This provides you with all the information you need, but only when
you need it.
- NullHandler: Any record it can handle will be thrown away. This can be used
to put on top of an existing handler stack to disable it temporarily.
- BufferHandler: This handler will buffer all the log records it receives
until
close()
is called at which point it will call handleBatch()
on the
handler it wraps with all the log messages at once. This is very useful to
send an email with all records at once for example instead of having one mail
for every log record.
- GroupHandler: This handler groups other handlers. Every record received is
sent to all the handlers it is configured with.
- FilterHandler: This handler only lets records of the given levels through
to the wrapped handler.
- TestHandler: Used for testing, it records everything that is sent to it and
has accessors to read out the information.
- WhatFailureGroupHandler: This handle extends the GroupHandler ignoring
exceptions raised by each child handler. This allows you to ignore issues
where a remote tcp connection may have died but you do not want your entire
application to crash and may wish to continue to log to other handlers.
Formatters
- LineFormatter: Formats a log record into a one-line string.
- HtmlFormatter: Used to format log records into a human readable html table, mainly suitable for emails.
- NormalizerFormatter: Normalizes objects/resources down to strings so a record can easily be serialized/encoded.
- ScalarFormatter: Used to format log records into an associative array of scalar values.
- JsonFormatter: Encodes a log record into json.
- WildfireFormatter: Used to format log records into the Wildfire/FirePHP protocol, only useful for the FirePHPHandler.
- ChromePHPFormatter: Used to format log records into the ChromePHP format, only useful for the ChromePHPHandler.
- GelfMessageFormatter: Used to format log records into Gelf message instances, only useful for the GelfHandler.
- LogstashFormatter: Used to format log records into logstash event json, useful for any handler listed under inputs here.
- ElasticaFormatter: Used to format log records into an Elastica\Document object, only useful for the ElasticSearchHandler.
- LogglyFormatter: Used to format log records into Loggly messages, only useful for the LogglyHandler.
- FlowdockFormatter: Used to format log records into Flowdock messages, only useful for the FlowdockHandler.
Processors
- IntrospectionProcessor: Adds the line/file/class/method from which the log call originated.
- WebProcessor: Adds the current request URI, request method and client IP to a log record.
- MemoryUsageProcessor: Adds the current memory usage to a log record.
- MemoryPeakUsageProcessor: Adds the peak memory usage to a log record.
- ProcessIdProcessor: Adds the process id to a log record.
- UidProcessor: Adds a unique identifier to a log record.
- GitProcessor: Adds the current git branch and commit to a log record.
- TagProcessor: Adds an array of predefined tags to a log record.
Utilities
- Registry: The
Monolog\Registry
class lets you configure global loggers that you
can then statically access from anywhere. It is not really a best practice but can
help in some older codebases or for ease of use.
- ErrorHandler: The
Monolog\ErrorHandler
class allows you to easily register
a Logger instance as an exception handler, error handler or fatal error handler.
- ErrorLevelActivationStrategy: Activates a FingersCrossedHandler when a certain log
level is reached.
- ChannelLevelActivationStrategy: Activates a FingersCrossedHandler when a certain
log level is reached, depending on which channel received the log record.
About
Requirements
- Monolog works with PHP 5.3 or above, and is also tested to work with HHVM.
Submitting bugs and feature requests
Bugs and feature request are tracked on GitHub
Frameworks Integration
- Frameworks and libraries using PSR-3
can be used very easily with Monolog since it implements the interface.
- Symfony2 comes out of the box with Monolog.
- Silex comes out of the box with Monolog.
- Laravel 4 comes out of the box with Monolog.
- PPI comes out of the box with Monolog.
- CakePHP is usable with Monolog via the cakephp-monolog plugin.
- Slim is usable with Monolog via the Slim-Monolog log writer.
- XOOPS 2.6 comes out of the box with Monolog.
- Aura.Web_Project comes out of the box with Monolog.
Author
Jordi Boggiano - j.boggiano@seld.be - http://twitter.com/seldaek
See also the list of contributors which participated in this project.
License
Monolog is licensed under the MIT License - see the LICENSE
file for details
Acknowledgements
This library is heavily inspired by Python's Logbook
library, although most concepts have been adjusted to fit to the PHP world.