In dockerMonitoring.writeToFile(), replace list of metrics with JSON file.

[fokaefs]

In order to make the method more generic and independent of predefined lists of metrics, I recommend to replace the long parameter list with a JSON file (the same that is saved in the database). Writing to a file, like writing to a database should be independent of the monitor (Docker or otherwise).

• [ Replace parameter list with JSON file]
• [ Add checks for missing metrics or empty file]
• [ Add warnings in a log for missing metrics or empty file. Do not interrupt the execution of the monitor. Do not use log4j for the logging part ]

[fokaefs]

A configuration file to specify the expected format of the JSON file may be necessary.

[wejdeneHaouari]

the JSON file should be an input from the user, or it's the a JSON variable similar to write_db function ?