Enable implicit default logger only in testing with -v

[apstndb]

What does this PR do?

This PR changes -v and -test.v=true handling only takes effect if testing.Testing() = true, i.e. go test.

Why is it important?

The current implementation always treats -v and -test.v=true specially, even outside of go test, and outputs verbose logs that are not easy to suppress. This makes it difficult to use testcontainers outside of go test.

Related issues

• Closes [Bug]: -v enable logs which is not intuitive to control #2874

How to test this PR

These behaviors should not be changed.

$ go test
$ go test -v
$ go test -test.v=true

These behavior will be changed to suppress default logging.

$ go run ./ -v

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[mdelapenya]

@apstndb thanks for opening the issue and working on the fix. I have one question about your use case: What do you expect when go run -v is executed?

From what I can see with the implementation in this PR, for the use case above of executing go run -v, we are going to always suppress the logging. I'd expect the -v flag enables the logging.

Could you share more on your use case so we can understand better the needs behind it? 🙏

[apstndb]

My expectation is that go run ./(or binary built by go build) won't generally follow go test convention.

• It won't know -test.v=true.
• It can use --verbose or -vv for vebose mode, and it can even use -v for other purpose.

It means the current behavior of enforcing go test convention to go run ./ is not good.

In this case, users can implement their own handling by explicitly setting testcontainers.Logger = logger or testcontainers.WithLogger(logger). It is not hard.