Can a form of esp_log_set_vprintf or similar function be created that passes the tag or log level? (IDFGH-15231)

[mbratch]

Is your feature request related to a problem?

I would like to intercept the logging using esp_log_set_vprintf and send, for example, to a syslog server. The syslog service understands the concept of "level" of message (e.g., error, warning, info, debug, etc). I would like to set the appropriate level in the syslog message. However, this information is not passed to esp_log_set_vprintf.

Describe the solution you'd like.

Is there a function that already does this, or perhaps such a function could be created? If it passed the log message tag that would be sufficient because then I could call esp_log_level_get.

Describe alternatives you've considered.

I've briefly considered parsing the text of the log message, knowing it is prefixed with a tag, but this is of course not a reliable way of obtaining the tag (i.e., not a good idea).

Additional context.

No response

[sudeep-mohanty]

Hi @mbratch,
As you rightly pointed out, the esp_log_set_vprintf does not support passing the log level. Thank you for the feature request. We will have have discussions within the team on this and let you know the approach. Thanks. cc: @KonstantinKondrashov

[mbratch]

@sudeep-mohanty thank you! Either log level or the tag would suffice since log level can be obtained from the tag.

[igrr]

It would be really nice if we allowed calling custom log formatting/storage functions over here:

esp-idf/components/log/src/log.c

Lines 58 to 73 in 38628f9

	esp_log_msg_t message = {
	.config = config,
	.tag = tag,
	.format = format,
	.timestamp = timestamp,
	.arg_types = NULL,
	};
	va_copy(message.args, args);
	#if ESP_LOG_MODE_BINARY_EN
	if (config.opts.binary_mode) {
	message.arg_types = va_arg(message.args, const char *);
	}
	esp_log_format_binary(&message);
	#else
	esp_log_format(&message);
	#endif // ESP_LOG_MODE_BINARY_EN

and not only the bundled esp_log_format and esp_log_format_binary. That would satisfy the feature request and also allow for development of out-of-tree log handling components (e.g. "log to Flash", "log to esp-insights", etc.)