useless settings json_minimal_level and json_file

[matthieumarrast]

Settings json_file and json_minimal_level in module config.ini does not have any effect when set:

[log]
# Duplicate some log messages in JSON to a specific file (for external
# monitoring tool)
# If json_file value is :
# null => the feature is desactivated
# AUTO => the feature is desactivated (because it's not necessary anymore
#         since 1.2 version)
json_file=log/foo.log

# Minimal level for this json log file
#  DEBUG => everything,
#  INFO => everything but not DEBUG,
#  WARNING => everything but not DEBUG and INFO,
#  ERROR => everything but not DEBUG, INFO and WARNING,
#  CRITICAL => everything but not DEBUG, INFO, WARNING AND ERROR
# Note: you can't send more messages to json log file than the configured global
#       minimal_level level (so also change the value of minimal_level key in
#       these uncommon use-cases)
json_minimal_level=INFO

Problem

In file https://github.com/metwork-framework/mfext/blob/master/adm/templates/profile
the environment variable MFLOG_JSON_FILE does not take any value if different than "AUTO":

# A little kind of magic to deal with [log]/json_file=AUTO
if test "{% raw %}${{% endraw %}{{MFMODULE}}_LOG_JSON_FILE{% raw %}:-}{% endraw %}" = "AUTO"; then
    export MFLOG_JSON_FILE="null"
fi

This variable is used in mflog for writing some logs to a json file, when no json log file is provided !? (see https://github.com/metwork-framework/mflog/blob/master/mflog/utils.py)

Proposed solution

Add export MFLOG_JSON_FILE="${MFDATA_LOG_JSON_FILE:-}" in else condition, as below:

# A little kind of magic to deal with [log]/json_file=AUTO
if test "{% raw %}${{% endraw %}{{MFMODULE}}_LOG_JSON_FILE{% raw %}:-}{% endraw %}" = "AUTO"; then
    export MFLOG_JSON_FILE="null"
else
    export MFLOG_JSON_FILE="${MFDATA_LOG_JSON_FILE:-}"
fi

Also if we set:

json_minimal_level=INFO
json_file=log/foo.log

Now some logs (with INFO level) are now written in file log/foo.log :

{"name": "default", "event": "the mfdata seems to be ok and does not need to be restarted", "level": "info", "pid": 138430, "plugin": "#core#", "timestamp": "2023-03-23T13:15:16.963584Z"}
{"name": "garbage_collector.sh", "event": "Starting...", "level": "info", "pid": 138876, "plugin": "#core#", "timestamp": "2023-03-23T13:16:04.126350Z"}
{"name": "garbage_collector.sh", "event": "End", "level": "info", "pid": 138883, "plugin": "#core#", "timestamp": "2023-03-23T13:16:04.340539Z"}

but I do not know why only the garbage_collector.sh and autorestart, which are also in garbage_collector.log and autorestart.log ... ?

Finality

In MetWork v2 what is the purpose of these settings and this json file ?
I feel like it's totally useless. So maybe we can delete them !? why it has not been done ? for legacy purpose ?
Moreover peoples are lost by the large amount of environment variables around logging.