add RfcUtcTime compilation option

[Ivansete-status]

Adding a simple option to allow logging using UTC TimeZone instead of the local one

This PR is motivated by these comments: status-im/status-desktop#15198 (comment) and status-im/status-desktop#15198 (comment) :)

[tersec]

Other concerns about the reasonableness aside, UnixTimeReadable is a bit of a red herring of an option name.

It's not about the "readability" (RfcTime is readable for example), it's about the UTC.

[tersec]

And the essence of Unix time is really that it's the seconds (or similar -- milliseconds or nanoseconds) count. If it's not that, it's not any kind of "Unix time" or epoch time.

[tersec]

I do wonder somewhat why the approach described in status-im/status-desktop#15198 (comment) isn't applicable here:

nwaku is not printing in UTC. Instead, it prints from the local time. What is happening is that the fleets' hosts have the local time set to UTC and therefore, nwaku gets that time zone.

Presumably the issue here is that

• there's a front-end UX which would be affected by running everything for testing purposes under TZ=UTC foo and
• these aren't mostly being run en masse as fleet nodes with UTC or GMT setups but intrinsically tend to run on individual laptops/desktops with people's actual local time zone?

Also, UnixTime addresses at least the consistent time reference point.

Other options are to add explicitly logged attributes in whatever timezone or formatting one wants. A bit redundant, but depends how scaffolding-y this is all meant to be.

[igor-sirotin]

... tend to run on individual laptops/desktops with people's actual local time zone?

@tersec yes, this is exactly the reason.

This is needed for status-desktop application. Since privacy is one of our core principles, we don't want to log anything that disclosures users identity. Yet we would like to get bug reports from them, which involves logs sharing.

So changing OS clock is not an option here.

[Ivansete-status]

I think it looks better now. Thanks for the naming suggestions @tersec ! ( we had a private chat )

[arnetheduck]

why the default here?

[arnetheduck]

there's an if for every formatting statement here - maybe accept that these are separate functions..?

[Ivansete-status]

Thanks so much indeed for the comments!
For this particular one, I think it is better to keep it in the same proc to avoid possible leftovers if we change that logic in the future.

[arnetheduck]

even so, most of it can be avoided..

let timezone =
  if useUtc: "Z"
  else:
     ...
     string.fromBytes(cachedZoneArray)