logging: Add show-startup-logs flag.

[apoorvapendse]

This enables the user to enable or disable the startup logs while starting the tusd server. It helps the user suppress the startup logs as per their preference.

The flag has a default value of true.
Fixes #1216.

Before:

---

After:

set as false:

set as true explicity:

default:

[Acconut]

Thank you for opening this PR! While I agree that it's useful to control the startup logs, I am not sure if a dedicated flag is the best approach. In #1216 (comment), I propose the idea of adding a generic flag for controlling the log level. If the log level does allow info messages, the startup logs would not be printed. Feel free to join the discussion in the other issue and let us know what you think.

This would also help us to remove the additional if statements that are introduced in this PR. They are quite cumbersome and I worry that in the future we forget about them and add direct log statements that should actually go in such an if statement. Using slog's method for logging at specific levels removes the need for these conditional clauses.

[apoorvapendse]

Thanks for the feedback.
I'd like to collaborate with you to make the log level feature, if that's fine.
Let me know how you are planning to approach it.
I will read up on the documentation of slog in the meantime.

[timabbott]

I think a better interface would be to have a function, printStartupLogLine, that does the ShowStartupLogs checks but is otherwise a wrapper for stdout.PrintF.

That'd avoid the excessive indentation here, as well as being likely a lot more robust to refactoring.

[apoorvapendse]

That makes sense to me.
@Acconut what do you think about this?

[timabbott]

You can probably just try implementing it; it's easier for maintainers to review a concept like this after seeing it. The current version seems unlikely to be merged.

[apoorvapendse]

Sure, I'll update this PR 👍
Thanks Tim!

[apoorvapendse]

I've made the updations.