v1.Container is still changing a log which caused the test to fail each time a
new field was added. To test loading, let's better use something that is
unlikely to change. The runtimev1.VersionResponse gets logged by kubelet and
seems to be stable.
When trying again with recent log files from the CI job, it was found that some
JSON messages get split across multiple lines, both in container logs and in
the systemd journal:
2022-12-21T07:09:47.914739996Z stderr F {"ts":1671606587914.691,"caller":"rest/request.go:1169","msg":"Response ...
2022-12-21T07:09:47.914984628Z stderr F 70 72 6f 78 79 10 01 1a 13 53 ... \".|\n","v":8}
Note the different time stamp on the second line. That first line is
long (17384 bytes). This seems to happen because the data must pass through a
stream-oriented pipe and thus may get split up by the Linux kernel.
The implication is that lines must get merged whenever the JSON decoder
encounters an incomplete line. The benchmark loader now supports that. To
simplifies this, stripping the non-JSON line prefixes must be done before using
a log as test data.
The updated README explains how to do that when downloading a CI job
result. The amount of manual work gets reduced by committing symlinks under
data to the expected location under ci-kubernetes-kind-e2e-json-logging and
ignoring them when the data is not there.
Support for symlinks gets removed and path/filepath is used instead of path
because it has better Windows support.
The benchmark depends on k8s.io/api (for v1.Container). Such a dependency is
not desirable for k8s.io/component-base/logs, even if it's just for
testing. The solution is to create a separate directory where such a dependency
isn't a problem.
The alternative, a separate package with its own go.mod file under
k8s.io/component-base/logs wouldd have been more complicated to maintain (yet
another go.mod file and different whitelisted dependencies).
