Add logger

[nichtich]

error_log is used in some places for tracing and debugging. Configuration should include settings for log level and internally use a PSR-3 compatible logging library such as Monolog, e.g.

$config->log->error("...")
$config->log->info("...")
$config->log->debug("...")

For debugging, the log level would be changed in configuration. Logging target could be stderr (error_log, the default as now), file, and syslog, this should be enough to support.

[pkiraly]

Agree, it is a technical debt of the project.

[pkiraly]

Here is a basic usage of Monolog:

use Monolog\Level;
use Monolog\Logger;
use Monolog\Handler\StreamHandler;

// create a log channel
$log = new Logger('name');
$log->pushHandler(new StreamHandler('path/to/your.log', Level::Warning));

// add records to the log
$log->warning('Foo');
$log->error('Bar');

The 'path/to/your.log' part could be read from configuration, but what would you like to see as default value, something like log/qa-catalogue.log?

There will be two new configuration parameters:

• logFile, logFile[id]: (string) a path of the log file. Default value: logs/qa-catalogue.log.
• logLevel, logLevel[id]: (string) the minimal logging level. Possible values are: DEBUG, INFO, NOTICE, WARNING, ERROR, CRITICAL, ALERT, EMERGENCY. If you set WARNING you will not receive DEBUG, INFO, and NOTICE messages. Default: WARNING.

[pkiraly]

We will use 2.5 for the time being because it supports PHP 7.2. monolog 3.x supports PHP 8.x only.

composer require monolog/monolog:^2.5

[nichtich]

I've extened the logger to use error_log by default and configurable to log to a file. Other methods such as syslog may be added if needed.

[pkiraly]

@nichtich Thanks! However I do not see your commits. Did you pushed them?

[nichtich]

See #de3bd88718cc0b

[pkiraly]

Sorry, I checked the main. Now I have reviewed it and merged to the main via a PR.