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
The sync frequency should be part of the syncLoop and resync no
less often than every X seconds. The current implementation runs
even if a config update was delivered less than X seconds ago.
Different information is needed to perform setup versus teardown. It
makes sense to separate these two interfaces since when we call teardown
from the reconciliation loop, we cannot rely on having the
information provided by the api definition of the volume.
Determines the set of active volumes versus the set of valid volumes
defined by the manifests. If there is an active volume that is not
defined in any of the manifests, deletes and cleans up that volume.
math.MaxInt64 represents 8 exabytes, which is a good limit for memory.
Also, this is the type used by Docker, so it's not possible to get any
value bigger than math.MaxInt64 as memory limit (both ram and swap) on a
Docker container.
Relevant discussion at #589 (more precisely,
https://github.com/GoogleCloudPlatform/kubernetes/pull/589#issuecomment-50640605).
This makes two main changes:
- Runs syncPod in a separate Go routine (and enforces only one of those
runs at a time).
- Uses the pod list to determine if a container should be running or
should be killed (used to use the output of syncPod).
Since Docker pulls are synchronized by the Docker daemon we still block
on that, but pods can now be removed and prepared for starting without
blocking on long pulls.
