Align the behavior of HTTP-based lifecycle handlers and HTTP-based
probers, converging on the probers implementation. This fixes multiple
deficiencies in the current implementation of lifecycle handlers
surrounding what functionality is available.
The functionality is gated by the features.ConsistentHTTPGetHandlers feature gate.
* De-share the Handler struct in core API
An upcoming PR adds a handler that only applies on one of these paths.
Having fields that don't work seems bad.
This never should have been shared. Lifecycle hooks are like a "write"
while probes are more like a "read". HTTPGet and TCPSocket don't really
make sense as lifecycle hooks (but I can't take that back). When we add
gRPC, it is EXPLICITLY a health check (defined by gRPC) not an arbitrary
RPC - so a probe makes sense but a hook does not.
In the future I can also see adding lifecycle hooks that don't make
sense as probes. E.g. 'sleep' is a common lifecycle request. The only
option is `exec`, which requires having a sleep binary in your image.
* Run update scripts
In 1f270ef4e2, we added 10KB as the read
limit for http probes. we should do the same for exec probes as well.
Change-Id: If154c5c4e669829ab94839c56260a894a6714f0f
For containers that don't have bash, we should support env substitution
like we do on command and args. However, without major refactoring
valueFrom is not supportable from inside the prober. For now, implement
substitution based on hardcoded env and leave TODOs for future work.
This allows us to interrupt/kill the executed command if it exceeds the
timeout (not implemented by this commit).
Set timeout in Exec probes. HTTPGet and TCPSocket probes respect the
timeout, while Exec probes used to ignore it.
Add e2e test for exec probe with timeout. However, the test is skipped
while the default exec handler doesn't support timeouts.
This might also preserve fragments, for those crazy enough to pass them.
I am using url.Parse() on the path in order to get path/query/fragment
and also deliberately avoiding the addition of more fields to the API.
Push status updates as soon as readiness state changes for containers,
rather than waiting for the sync loop to update the status. In
particular, this should help new containers to come online faster.
Additionally, consolidates prober test helpers into a single file.
This commit builds on previous work and creates an independent
worker for every liveness probe. Liveness probes behave largely the same
as readiness probes, so much of the code is shared by introducing a
probeType paramater to distinguish the type when it matters. The
circular dependency between the runtime and the prober is broken by
exposing a shared liveness ResultsManager, owned by the
kubelet. Finally, an Updates channel is introduced to the ResultsManager
so the kubelet can react to unhealthy containers immediately.
Change all references to the container ID in pkg/kubelet/... to the
strong type defined in pkg/kubelet/container: ContainerID
The motivation for this change is to make the format of the ID
unambiguous, specifically whether or not it includes the runtime
prefix (e.g. "docker://").
Each container with a readiness has an individual go-routine which
handles periodic probing for that container. The results are cached, and
written to the status.Manager in the pod sync path.
