发布于 2015-08-27 16:40:54 | 238 次阅读 | 评论: 0 | 来源: 网络整理
Monolog is a logging library for PHP used by Symfony. It is inspired by the Python LogBook library.
To log a message simply get the logger service from the container in
your controller:
public function indexAction()
{
$logger = $this->get('logger');
$logger->info('I just got the logger');
$logger->error('An error occurred');
// ...
}
The logger service has different methods for different logging levels.
See LoggerInterface for details on which methods are available.
In Monolog each logger defines a logging channel, which organizes your log messages into different “categories”. Then, each channel has a stack of handlers to write the logs (the handlers can be shared).
小技巧
When injecting the logger in a service you can use a custom channel control which “channel” the logger will log to.
The basic handler is the StreamHandler which writes logs in a stream
(by default in the app/logs/prod.log in the prod environment and
app/logs/dev.log in the dev environment).
Monolog comes also with a powerful built-in handler for the logging in
prod environment: FingersCrossedHandler. It allows you to store the
messages in a buffer and to log them only if a message reaches the
action level (error in the configuration provided in the Standard
Edition) by forwarding the messages to another handler.
The logger uses a stack of handlers which are called successively. This allows you to log the messages in several ways easily.
# app/config/config.yml
monolog:
handlers:
applog:
type: stream
path: /var/log/symfony.log
level: error
main:
type: fingers_crossed
action_level: warning
handler: file
file:
type: stream
level: debug
syslog:
type: syslog
level: error
<!-- app/config/config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
http://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<monolog:config>
<monolog:handler
name="applog"
type="stream"
path="/var/log/symfony.log"
level="error"
/>
<monolog:handler
name="main"
type="fingers_crossed"
action-level="warning"
handler="file"
/>
<monolog:handler
name="file"
type="stream"
level="debug"
/>
<monolog:handler
name="syslog"
type="syslog"
level="error"
/>
</monolog:config>
</container>
// app/config/config.php
$container->loadFromExtension('monolog', array(
'handlers' => array(
'applog' => array(
'type' => 'stream',
'path' => '/var/log/symfony.log',
'level' => 'error',
),
'main' => array(
'type' => 'fingers_crossed',
'action_level' => 'warning',
'handler' => 'file',
),
'file' => array(
'type' => 'stream',
'level' => 'debug',
),
'syslog' => array(
'type' => 'syslog',
'level' => 'error',
),
),
));
The above configuration defines a stack of handlers which will be called in the order they are defined.
小技巧
The handler named “file” will not be included in the stack itself as
it is used as a nested handler of the fingers_crossed handler.
注解
If you want to change the config of MonologBundle in another config file you need to redefine the whole stack. It cannot be merged because the order matters and a merge does not allow to control the order.
The handler uses a Formatter to format the record before logging
it. All Monolog handlers use an instance of
MonologFormatterLineFormatter by default but you can replace it
easily. Your formatter must implement
MonologFormatterFormatterInterface.
# app/config/config.yml
services:
my_formatter:
class: MonologFormatterJsonFormatter
monolog:
handlers:
file:
type: stream
level: debug
formatter: my_formatter
<!-- app/config/config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
http://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<services>
<service id="my_formatter" class="MonologFormatterJsonFormatter" />
</services>
<monolog:config>
<monolog:handler
name="file"
type="stream"
level="debug"
formatter="my_formatter"
/>
</monolog:config>
</container>
// app/config/config.php
$container
->register('my_formatter', 'MonologFormatterJsonFormatter');
$container->loadFromExtension('monolog', array(
'handlers' => array(
'file' => array(
'type' => 'stream',
'level' => 'debug',
'formatter' => 'my_formatter',
),
),
));
Monolog allows you to process the record before logging it to add some extra data. A processor can be applied for the whole handler stack or only for a specific handler.
小技巧
Beware that log file sizes can grow very rapidly, leading to disk space exhaustion.
This is specially true in the dev environment, where a simple request can
generate hundreds of log lines. Consider using tools like the logrotate
Linux command to rotate log files before they become a problem.
A processor is simply a callable receiving the record as its first argument.
Processors are configured using the monolog.processor DIC tag. See the
reference about it.
Sometimes it is hard to tell which entries in the log belong to which session and/or request. The following example will add a unique token for each request using a processor.
namespace AcmeMyBundle;
use SymfonyComponentHttpFoundationSessionSession;
class SessionRequestProcessor
{
private $session;
private $token;
public function __construct(Session $session)
{
$this->session = $session;
}
public function processRecord(array $record)
{
if (null === $this->token) {
try {
$this->token = substr($this->session->getId(), 0, 8);
} catch (RuntimeException $e) {
$this->token = '????????';
}
$this->token .= '-' . substr(uniqid(), -8);
}
$record['extra']['token'] = $this->token;
return $record;
}
}
# app/config/config.yml
services:
monolog.formatter.session_request:
class: MonologFormatterLineFormatter
arguments:
- "[%%datetime%%] [%%extra.token%%] %%channel%%.%%level_name%%: %%message%%n"
monolog.processor.session_request:
class: AcmeMyBundleSessionRequestProcessor
arguments: ["@session"]
tags:
- { name: monolog.processor, method: processRecord }
monolog:
handlers:
main:
type: stream
path: "%kernel.logs_dir%/%kernel.environment%.log"
level: debug
formatter: monolog.formatter.session_request
<!-- app/config/config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
http://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<services>
<service id="monolog.formatter.session_request"
class="MonologFormatterLineFormatter">
<argument>[%%datetime%%] [%%extra.token%%] %%channel%%.%%level_name%%: %%message%%
</argument>
</service>
<service id="monolog.processor.session_request"
class="AcmeMyBundleSessionRequestProcessor">
<argument type="service" id="session" />
<tag name="monolog.processor" method="processRecord" />
</service>
</services>
<monolog:config>
<monolog:handler
name="main"
type="stream"
path="%kernel.logs_dir%/%kernel.environment%.log"
level="debug"
formatter="monolog.formatter.session_request"
/>
</monolog:config>
</container>
// app/config/config.php
$container
->register(
'monolog.formatter.session_request',
'MonologFormatterLineFormatter'
)
->addArgument('[%%datetime%%] [%%extra.token%%] %%channel%%.%%level_name%%: %%message%%n');
$container
->register(
'monolog.processor.session_request',
'AcmeMyBundleSessionRequestProcessor'
)
->addArgument(new Reference('session'))
->addTag('monolog.processor', array('method' => 'processRecord'));
$container->loadFromExtension('monolog', array(
'handlers' => array(
'main' => array(
'type' => 'stream',
'path' => '%kernel.logs_dir%/%kernel.environment%.log',
'level' => 'debug',
'formatter' => 'monolog.formatter.session_request',
),
),
));
注解
If you use several handlers, you can also register a processor at the handler level or at the channel level instead of registering it globally (see the following sections).
You can register a processor per handler using the handler option of
the monolog.processor tag:
# app/config/config.yml
services:
monolog.processor.session_request:
class: AcmeMyBundleSessionRequestProcessor
arguments: ["@session"]
tags:
- { name: monolog.processor, method: processRecord, handler: main }
<!-- app/config/config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
http://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<services>
<service id="monolog.processor.session_request"
class="AcmeMyBundleSessionRequestProcessor">
<argument type="service" id="session" />
<tag name="monolog.processor" method="processRecord" handler="main" />
</service>
</services>
</container>
// app/config/config.php
$container
->register(
'monolog.processor.session_request',
'AcmeMyBundleSessionRequestProcessor'
)
->addArgument(new Reference('session'))
->addTag('monolog.processor', array('method' => 'processRecord', 'handler' => 'main'));
You can register a processor per channel using the channel option of
the monolog.processor tag:
# app/config/config.yml
services:
monolog.processor.session_request:
class: AcmeMyBundleSessionRequestProcessor
arguments: ["@session"]
tags:
- { name: monolog.processor, method: processRecord, channel: main }
<!-- app/config/config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:monolog="http://symfony.com/schema/dic/monolog"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/monolog
http://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
<services>
<service id="monolog.processor.session_request"
class="AcmeMyBundleSessionRequestProcessor">
<argument type="service" id="session" />
<tag name="monolog.processor" method="processRecord" channel="main" />
</service>
</services>
</container>
// app/config/config.php
$container
->register(
'monolog.processor.session_request',
'AcmeMyBundleSessionRequestProcessor'
)
->addArgument(new Reference('session'))
->addTag('monolog.processor', array('method' => 'processRecord', 'channel' => 'main'));