Many users attempt to use 'kubectl logs' in order to find the logs
for a container, but receive no logs or an error telling them their
container is not running. The fix in this case is to run with '--previous',
but this does not match user expectations for the logs command.
This commit changes the behavior of the Kubelet to return the logs of
the currently running container or the previous running container unless
the user provides the "previous" flag. If the user specifies "follow"
the logs of the most recent container will be displayed, and if it is
a terminated container the logs will come to an end (the user can
repeatedly invoke 'kubectl logs --follow' and see the same output).
Clean up error messages in the kubelet log path to be consistent and
give users a more predictable experience.
Have the Kubelet return 400 on invalid requests
Add a `/stats/summary` endpoint to the kubelet which will return an
empty Summary{} struct (json formatted), as a summary API
placeholder. Once the next cAdvisor release is vendored, the summary
API will be filled in.
Changes include:
- Moving stats serving & routes to pkg/kubelet/server/stats/handler.go
- Managing the routes with restful.WebService, rather than manual
parsing
- Misc cleanup
These changes will make adding the new routes for /stats/summary more
manageable.
- Sample is now the toplevel struct, so all child structs have the same
timestamp
- Removed FilesystemStats. There are more discussions needed
wrt. volumes and disk accounting, so this will be added in a follow
up PR
- Removed Options. The most recent sample will be returned.
This API has been discussed ad nauseam across several forums, and this
API represents the latest conclusion. In summary, we will provide this
API as temporary solution for providing the new stats required for 1.2.
In the longterm this API will be split into "essential" stats, which
will be provided by a first-party API served through the kubelet, and
"non-essential" (monitoring) stats, which will be provided by a 3rd
party API served from a pod.
Refactor Kubelet's server functionality into a server package. Most
notably, move pkg/kubelet/server.go into
pkg/kubelet/server/server.go. This will lead to better separation of
concerns and a more readable code hierarchy.
This leaves `pkg/kubelet/server/server.go` looking a little ugly as there is an extra layer of "config" structs that isn't needed. This is left as a TODO for now.
k8s-merge-robot