Ability to dynamically change loglevel

[rentallect]

At initialization, the loglevel is set based on how the ZITI_AGENT_LOGLEVEL env var is configured. It is sometimes necessary to increase the verbosity of the logging (for trouble shooting), and then decease it later. We need the ability to do so without restarting the agent.

[rentallect]

This snippet shows that if we give each transport a name, keyed by the name, then we can have access to it via ref (since the logger object is inaccessible directly). The agent's REST API would then expose an endpoint able to seek out the "console" transport ref, and then alter its loglevel.

var self = this;
var keyBy = require('lodash.keyby');
self.logger = self.winston.createLogger({
        levels:self.winston.config.syslog.levels
        ,transports:
            [
                new self.winston.transports.Console({
                    level: self.config.console.level.ref
                    ,formatter: self._consoleLogFormatter
                    ,name: 'console'
                })
            ]
    });

    self.transports = keyBy(self.logger.transports,"name");
    self.transports.console.level = 'info';

[qrkourier]

I believe this feature was added.

[rentallect]

@qrkourier dynamic client-side log-level adjustments shipped a while ago, but this issue is about dynamic changes to the Bootstrapper's log-level