Add line-seperation character for better multiline logs handling using logspout

[mrnicegyu11]

As stated by @sanderegg , it is apparently fairly easily for us to add an "end-of--current-log" separation-character to aid the grouping of multiline logs.

From the ops-side, we use a go regex to match the first line for a multiline-log using logspout. Once the regex is matched again, a new log-entry is started. All lines in between are considered as one multiline-log, starting with the first line, i.e. the one that matched the regex. (More info on this can be found in the logspout docker readme, we use MULTILINE_MATCH=first )

Currently we match ^(ERROR|WARNING|INFO|DEBUG|CRITICAL)[:]. This fails when terminal-colors are logged, an PR fixing this is pending here.

Actionable tasks:

• Come up with a separation phrase or character that can be matched using a go-regex, but is non-intrusive when reading the logs. (Some non-perfect ideas: OSPARC_LOG, !!\n, ...)
• Implement it in simcore
• Add this match to the regex used in logspout

Thanks, let's discuss and see if we can do it.

[pcrespov]

Please @mrnicegyu11 check as well

• 2204

• 2157

[sanderegg]

note that logspout was phazed out. we use docker dual logging now and the logs go straight to Graylog

[matusdrobuliak66]

as mentioned before we do not use logspout anymore, and other mentioned things are already discussed here https://github.com/ITISFoundation/osparc-simcore/issues/4079