ginkgo.GinkgoHelper is a recent addition to ginkgo which allows functions to
mark themselves as helper. This then changes which callstack gets reported for
failures. It makes sense to support the same mechanism also for logging.
There's also no reason why framework.Logf should produce output that is in a
different format than klog log entries. Having time stamps formatted
differently makes it hard to read test output which uses a mixture of both.
Another user-visible advantage is that the error log entry from
framework.ExpectNoError now references the test source code.
With textlogger there is a simple replacement for klog that can be reconfigured
to let the caller handle stack unwinding. klog itself doesn't support that
and should be modified to support it (feature freeze).
Emitting printf-style output via that logger would work, but become less
readable because the message string would get quoted instead of printing it
verbatim as before. So instead, the traditional klog header gets reproduced
in the framework code. In this example, the first line is from klog, the second
from Logf:
I0111 11:00:54.088957 332873 factory.go:193] Registered Plugin "containerd"
...
I0111 11:00:54.987534 332873 util.go:506] >>> kubeConfig: /var/run/kubernetes/admin.kubeconfig
Indention is a bit different because the initial output is printed before
installing the logger which writes through ginkgo.GinkgoWriter.
One welcome side effect is that now "go vet" detects mismatched parameters for
framework.Logf because fmt.Sprintf is called without mangling the format
string. Some of the calls were incorrect.