It currently is impossible to use two healthz handlers on different
ports in the same process. This removes the global variables in favor
of requiring the consumer to specify all health checks up front.
Currently, API server is not aware of the static pods (manifests from
sources other than the API server, e.g. file and http) at all. This is
inconvenient since users cannot check the static pods through kubectl.
It is also sub-optimal because scheduler is unaware of the resource
consumption by these static pods on the node.
This change syncs the information back to the API server by creating a
mirror pod via API server for each static pod.
- Kubelet creates containers for the static pod, as it would do
normally.
- If a mirror pod gets deleted, Kubelet will re-create one. The
containers are sync'd to the static pods, so they will not be
affected.
- If a static pod gets removed from the source (e.g. manifest file
removed from the directory), the orphaned mirror pod will be deleted.
Note that because events are associated with UID, and the mirror pod has
a different UID than the original static pod, the events will not be
shown for the mirror pod when running `kubectl describe pod
<mirror_pod>`.
During the kubelet's /healthz responce check to see if the
hostname used by the master matches the hostname the kubelet
knows itself by. If not fail the health check.
Signed-off-by: Sami Wagiaalla <swagiaal@redhat.com>
There are three values that uniquely identify a pod on a host -
the configuration source (etcd, file, http), the pod name, and the
pod namespace. This change ensures that configuration properly
makes those names unique by changing podFullName to contain both
name (currently ID in v1beta1, Name in v1beta3) and namespace.
The Kubelet does not properly handle information requests for
pods not in the default namespace at this time.
Move a lot of common error logging into better buckets:
glog.Errorf() - Always an error
glog.Warningf() - Something unexpected, but probably not an error
glog.V(0) - Generally useful for this to ALWAYS be visible
to an operator
* Programmer errors
* Logging extra info about a panic
* CLI argument handling
glog.V(1) - A reasonable default log level if you don't want
verbosity
* Information about config (listening on X, watching Y)
* Errors that repeat frequently that relate to conditions
that can be corrected (pod detected as unhealthy)
glog.V(2) - Useful steady state information about the service
* Logging HTTP requests and their exit code
* System state changing (killing pod)
* Controller state change events (starting pods)
* Scheduler log messages
glog.V(3) - Extended information about changes
* More info about system state changes
glog.V(4) - Debug level verbosity (for now)
* Logging in particularly thorny parts of code where
you may want to come back later and check it
Also rename some to other names that make better reading. There are still a
bunch of "make" functions but they do things like assemble a string from parts
or build an array of things. It seemed that "make" there seemed fine. "New"
is for "constructors".
Also transfer the Kubelet from using ContainerManifest.ID to source specific
identifiers with namespacing. Move goroutine behavior out of kubelet/ and
into integration.go and cmd/kubelet/kubelet.go for better isolation.
