The goal of this change is to remove the registration of signal
handling from pkg/kubelet. We now pass in a stop channel.
If you register a signal handler in `main()` to aid in a controlled
and deliberate exit then the handler registered in `pkg/kubelet` often
wins and the process exits immediately. This means all other signal
handler registrations are currently racy if `DockerServer.Start()` is
directly or indirectly invoked.
This change also removes another signal handler registration from
`NewAPIServerCommand()`; a stop channel is now passed to this
function.
With d7ddcca231, we lost the logging
of the flags. We should at least log what the command line flags
were used to start processes as those incredibly useful for trouble shooting.
This explicitly registers Kubelet flags from libraries that were
registering flags globally, and stops parsing the global flag set.
In general, we should always be explicit about flags we register
and parse, so that we maintain control over our command-line API.
Changes the Kubelet configuration flag precedence order so that flags
take precedence over config from files/ConfigMaps.
See issue #56171 for more details.
Also modifies e2e node test suite to transform all relevant Kubelet
flags into a config file before starting tests when the
KubeletConfigFile feature gate is true, and turns on the
KubeletConfigFile gate for all e2e node tests. This allows the alpha
dynamic Kubelet config feature to continue to work in tests after
the precedence change.
Revert "Merge pull request #51857 from kubernetes/revert-51307-kc-type-refactor"
This reverts commit 9d27d92420, reversing
changes made to 2e69d4e625.
See original: #51307
We punted this from 1.8 so it could go through an API review. The point
of this PR is that we are trying to stabilize the kubeletconfig API so
that we can move it out of alpha, and unblock features like Dynamic
Kubelet Config, Kubelet loading its initial config from a file instead
of flags, kubeadm and other install tools having a versioned API to rely
on, etc.
We shouldn't rev the version without both removing all the deprecated
junk from the KubeletConfiguration struct, and without (at least
temporarily) removing all of the fields that have "Experimental" in
their names. It wouldn't make sense to lock in to deprecated fields.
"Experimental" fields can be audited on a 1-by-1 basis after this PR,
and if found to be stable (or sufficiently alpha-gated), can be restored
to the KubeletConfiguration without the "Experimental" prefix.
Command line flag API remains the same. This allows ComponentConfig
structures (e.g. KubeletConfiguration) to express the map structure
behind feature gates in a natural way when written as JSON or YAML.
For example:
KubeletConfiguration Before:
```
apiVersion: kubeletconfig/v1alpha1
kind: KubeletConfiguration
featureGates: "DynamicKubeletConfig=true,Accelerators=true"
```
KubeletConfiguration After:
```
apiVersion: kubeletconfig/v1alpha1
kind: KubeletConfiguration
featureGates:
DynamicKubeletConfig: true
Accelerators: true
```
Automatic merge from submit-queue (batch tested with PRs 50381, 51307, 49645, 50995, 51523)
Remove deprecated and experimental fields from KubeletConfiguration
As we work towards providing a stable (v1) kubeletconfig API,
we cannot afford to have deprecated or "experimental" (alpha) fields
living in the KubeletConfiguration struct. This removes all existing
experimental or deprecated fields, and places them in KubeletFlags
instead.
I'm going to send another PR after this one that organizes the remaining
fields into substructures for readability. Then, we should try to move
to v1 ASAP (maybe not v1 in 1.8, given how close we are, but definitely in 1.9).
It makes far more sense to focus on a clean API in kubeletconfig v2,
than to try and further clean up the existing "API" that everyone
already depends on.
fixes: #51657
**Release note**:
```release-note
NONE
```
As we work towards providing a stable (v1) kubeletconfig API,
we cannot afford to have deprecated or "experimental" (alpha) fields
living in the KubeletConfiguration struct. This removes all existing
experimental or deprecated fields, and places them in KubeletFlags
instead.
I'm going to send another PR after this one that organizes the remaining
fields into substructures for readability. Then, we should try to move
to v1 ASAP.
It makes far more sense to focus on a clean API in kubeletconfig v2,
than to try and further clean up the existing "API" that everyone
already depends on.
Automatic merge from submit-queue (batch tested with PRs 50967, 50505, 50706, 51033, 51028)
Revert "Merge pull request #51008 from kubernetes/revert-50789-fix-scheme"
I'm spinning up a cluster right now to test this fix, but I'm pretty sure this was the problem.
There doesn't seem to be a way to confirm from logs, because AFAICT the logs from the hollow kubelet containers are not collected as part of the kubemark test.
**What this PR does / why we need it**:
This reverts commit f4afdecef8, reversing
changes made to e633a1604f.
This also fixes a bug where Kubemark was still using the core api scheme
to manipulate the Kubelet's types, which was the cause of the initial
revert.
**Which issue this PR fixes**: fixes#51007
**Release note**:
```release-note
NONE
```
/cc @shyamjvs @wojtek-t
This reverts commit f4afdecef8, reversing
changes made to e633a1604f.
This also fixes a bug where Kubemark was still using the core api scheme
to manipulate the Kubelet's types, which was the cause of the initial
revert.
First is initializing a KubeletConfig that starts no background
processes. Second is running the config. Provide a legacy path
that won't impact older callers while making it easier to customize
the interfaces passed to the Kubelet.
Used by OpenShift to inject some custom interfaces to the Kubelet
for config management.
I had the kublet die on startup and the only error was "0x401da0" Which
I assume is an address of the err.Error function. The other way to fix
this, I think, would be to use err.Error(), however that could cause
fmt.Fprintf() problems, debuging on the error message people used.
Now I get a nice clean error I can understand:
"cAdvisor.New() err = mountpoint for cpu not found"
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.
Break up the monolithic volumes code in kubelet into very small individual
modules with a well-defined interface. Move them all into their own packages
and beef up testing along the way.
Marek Counts