This continues the work in
https://github.com/kubernetes/kubernetes/pull/81426 by also moving the
logger_test.go, moving the log helper code from util.go to log.go (a
more logical place, as it is only used there) and updating comments.
After merging
259bb3bef5 (diff-eb7b79470992813ea1905e96c298b47b)
ExpectEqual and some of the other wrappers logged the failure twice,
once inside the wrapper itself and once in the failure handler.
Logging the stack backtrace is useful because many assertions still
don't contain an explanation and therefore knowing where they occur is
crucial. Now all failures are logged with a "Full Stack Trace", not
just those with a wrapper. The stack is pruned to skip over wrapper
functions and removes Ginkgo internal functions to keep the stack
trace smaller.
Failures occuring in the wrappers were recorded as occuring in those
wrappers. Now the wrappers are skipped and the caller is recorded
instead.
The full stack trace recorded by Ginkgo 1.10.0 is currently off by one
entry. This needs to be fixed in Ginkgo, then the test can be updated.
All failures are worth logging immediately, not just unexpected
errors. That helps understand tests that have long-running cleanup
operations with their own logging, because the failure will be visible
inside the test output.
The logging in framework.ExpectNoError also was rather poor, because
it only showed the error, but not the additional information about it.
Tests suites now should use log.Fail as Gomega failure handler instead
of ginkgowrapper.Fail. log.Fail will handle the logging for all
failures before proceeding to record the failure in Ginkgo.
Because logging is always done also after a test failure, additional
failures during cleanup are now visible. Ginkgo itself just ignores
them.
We tried to separate logger functionality as subpackage of e2e test
framework, but we've recognized that should be core functionality
and we should keep it as core of e2e test framework after facing
circular dependency issues.
So this adds log.go back to core of e2e test framework. In addition,
this makes volume sub package use the core logger as a sample.
