Automatic merge from submit-queue (batch tested with PRs 40328, 40057)
Allows kubectl create -f to filter by selector.
From #32544.
The underlying `seletor` infrastructrue was implemented by #32599. The test is basically copy-paste of the corresponding test for `kubectl apply -f -l`.
```release-note
kubectl create now accepts the label selector flag for filtering objects to create
```
Enforce the following limits:
12kb for total message length in container status
4kb for the termination message path file
2kb or 80 lines (whichever is shorter) from the log on error
Fallback to log output if the user requests it.
Automatic merge from submit-queue (batch tested with PRs 38445, 40292)
Add the ability to edit fields within a config map.
Addresses part of https://github.com/kubernetes/kubernetes/issues/36222
Example command:
```console
$ kubectl edit configmap foo --config-map-data=bar
```
Will open the data element named `bar` in the `ConfigMap` named `foo` in `$EDITOR`, the edited contents are then updated back to the config map.
@kubernetes/sig-cli
```release-note
Add a special purpose tool for editing individual fields in a ConfigMap with kubectl
```
Automatic merge from submit-queue
[Federation] Expose autoscaling apis through federation api server
This PR implements first part of federated pod autoscaler.
The issue to handle the whole feature is https://github.com/kubernetes/kubernetes/issues/38974
cc @kubernetes/sig-cluster-federation
@shashidharatd @kshafiee @deepak-vij
**Release note**:
```
federation users can now use federated autoscaling resources and create federated horizontalpodautoscalers
```
Automatic merge from submit-queue (batch tested with PRs 37228, 40146, 40075, 38789, 40189)
kubeadm: add optional self-hosted deployment
**What this PR does / why we need it**: add an optional self-hosted deployment type to `kubeadm`, for master components only, namely `apiserver`, `controller-manager` and `scheduler`.
**Which issue this PR fixes**: closes#38407
**Special notes for your reviewer**: /cc @aaronlevy @luxas @dgoodwin
**Release note**:
```release-note
kubeadm: add optional self-hosted deployment for apiserver, controller-manager and scheduler.
```
Automatic merge from submit-queue (batch tested with PRs 37228, 40146, 40075, 38789, 40189)
kubelet: storage: teardown terminated pod volumes
This is a continuation of the work done in https://github.com/kubernetes/kubernetes/pull/36779
There really is no reason to keep volumes for terminated pods attached on the node. This PR extends the removal of volumes on the node from memory-backed (the current policy) to all volumes.
@pmorie raised a concern an impact debugging volume related issues if terminated pod volumes are removed. To address this issue, the PR adds a `--keep-terminated-pod-volumes` flag the kubelet and sets it for `hack/local-up-cluster.sh`.
For consideration in 1.6.
Fixes#35406
@derekwaynecarr @vishh @dashpole
```release-note
kubelet tears down pod volumes on pod termination rather than pod deletion
```
Automatic merge from submit-queue (batch tested with PRs 40168, 40165, 39158, 39966, 40190)
CRI: upgrade protobuf to v3
For #38854, this PR upgrades CRI protobuf version to v3, and also updated related packages for confirming to new api.
**Release note**:
```
CRI: upgrade protobuf version to v3.
```
Automatic merge from submit-queue (batch tested with PRs 39772, 39831, 39481, 40167, 40149)
Add //hack:verify-boilerplate rule.
This pattern is working well in test-infra. I'll add the gofmt and go vet rules next.
Automatic merge from submit-queue
promote certificates api to beta
Mostly posting to see what breaks but also this API is ready to be promoted.
```release-note
Promote certificates.k8s.io to beta and enable it by default. Users using the alpha certificates API should delete v1alpha1 CSRs from the API before upgrading and recreate them as v1beta1 CSR after upgrading.
```
@kubernetes/api-approvers @jcbsmpsn @pipejakob
Automatic merge from submit-queue
Add authorization mode to kubeadm
This PR adds an option in `kubeadm` to allow a user to specify an [authorization plugin](https://kubernetes.io/docs/admin/authorization/). It defaults to RBAC.
Automatic merge from submit-queue
Build release tars using bazel
**What this PR does / why we need it**: builds equivalents of the various kubernetes release tarballs, solely using bazel.
For example, you can now do
```console
$ make bazel-release
$ hack/e2e.go -v -up -test -down
```
**Special notes for your reviewer**: this is currently dependent on 3b29803eb5, which I have yet to turn into a pull request, since I'm still trying to figure out if this is the best approach.
Basically, the issue comes up with the way we generate the various server docker image tarfiles and load them on nodes:
* we `md5sum` the binary being encapsulated (e.g. kube-proxy) and save that to `$binary.docker_tag` in the server tarball
* we then build the docker image and tag using that md5sum (e.g. `gcr.io/google_containers/kube-proxy:$MD5SUM`)
* we `docker save` this image, which embeds the full tag in the `$binary.tar` file.
* on cluster startup, we `docker load` these tarballs, which are loaded with the tag that we'd created at build time. the nodes then use the `$binary.docker_tag` file to find the right image.
With the current bazel `docker_build` rule, the tag isn't saved in the docker image tar, so the node is unable to find the image after `docker load`ing it.
My changes to the rule save the tag in the docker image tar, though I don't know if there are subtle issues with it. (Maybe we want to only tag when `--stamp` is given?)
Also, the docker images produced by bazel have the timestamp set to the unix epoch, which is not great for debugging. Might be another thing to change with a `--stamp`.
Long story short, we probably need to follow up with bazel folks on the best way to solve this problem.
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue (batch tested with PRs 39625, 39842)
Add RBAC v1beta1
Add `rbac.authorization.k8s.io/v1beta1`. This scrubs `v1alpha1` to remove cruft, then add `v1beta1`. We'll update other bits of infrastructure to code to `v1beta1` as a separate step.
```release-note
The `attributeRestrictions` field has been removed from the PolicyRule type in the rbac.authorization.k8s.io/v1alpha1 API. The field was not used by the RBAC authorizer.
```
@kubernetes/sig-auth-misc @liggitt @erictune
Automatic merge from submit-queue
Remove packages which are now apimachinery
Removes all the content from the packages that were moved to `apimachinery`. This will force all vendoring projects to figure out what's wrong. I had to leave many empty marker packages behind to have verify-godep succeed on vendoring heapster.
@sttts straight deletes and simple adds
Automatic merge from submit-queue (batch tested with PRs 39911, 40002, 39969, 40012, 40009)
kubectl: fix rollback dryrun when version is not specified
@kubernetes/sig-cli-misc
Automatic merge from submit-queue (batch tested with PRs 39609, 39105)
Stop running most unit tests outside of bazel.
Lets not duplicate our efforts. The two I still run here are the two we currently skip in bazel. We should fix those.
This does 3 things:
1. env var to retain the /tmp/godep
2. env var to use a specified /tmp/godep
3. rework of preload-dep to support more non-github things, like go4.org
Automatic merge from submit-queue (batch tested with PRs 39803, 39698, 39537, 39478)
include bootstrap admin in super-user group, ensure tokens file is correct on upgrades
Fixes https://github.com/kubernetes/kubernetes/issues/39532
Possible issues with cluster bring-up scripts:
- [x] known_tokens.csv and basic_auth.csv is not rewritten if the file already exists
* new users (like the controller manager) are not available on upgrade
* changed users (like the kubelet username change) are not reflected
* group additions (like the addition of admin to the superuser group) don't take effect on upgrade
* this PR updates the token and basicauth files line-by-line to preserve user additions, but also ensure new data is persisted
- [x] existing 1.5 clusters may depend on more permissive ABAC permissions (or customized ABAC policies). This PR adds an option to enable existing ABAC policy files for clusters that are upgrading
Follow-ups:
- [ ] both scripts are loading e2e role-bindings, which only be loaded in e2e tests, not in normal kube-up scenarios
- [ ] when upgrading, set the option to use existing ABAC policy files
- [ ] update bootstrap superuser client certs to add superuser group? ("We also have a certificate that "used to be" a super-user. On GCE, it has CN "kubecfg", on GKE it's "client"")
- [ ] define (but do not load by default) a relaxed set of RBAC roles/rolebindings matching legacy ABAC, and document how to load that for new clusters that do not want to isolate user permissions
Automatic merge from submit-queue
Fix kubectl get -f <file> -o <nondefault printer> so it prints all items in the file
**What this PR does / why we need it**: Fix kubectl get -f <file> -o <nondefault printer> so it prints all the objects in the file, instead of just the first one. Also add a test for this feature.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#38907
**Special notes for your reviewer**:
**Release note**:
```release-note
```
cc @AdoHe @deads2k @liggitt @fabianofranz @kubernetes/kubectl @kubernetes/sig-cli-misc
Fix kubectl get -f <file> -o <nondefault printer> so it prints all the
objects in the file, instead of just the first one. Also add a test for
this feature.
Automatic merge from submit-queue (batch tested with PRs 39673, 39536, 39617, 39540, 39686)
Generate stable bindata output
fixes#30621
bindata generation produces spurious diffs when run with different go versions because gzip output is not stable between versions.
It also produces spurious diffs when invoked directly vs via make/go:generate.
This PR:
* adds data to bindata uncompressed (makes translation files human-readable, and the zip files were already compressed... for reference the file was 27.7 KB before, and 20.1 KB with this change)
* runs the generation from KUBE_ROOT, so it doesn't matter whether it is invoked directly or via go:generate
supercedes https://github.com/kubernetes/kubernetes/pull/39631
Automatic merge from submit-queue (batch tested with PRs 39486, 37288, 39477, 39455, 39542)
Allow missing keys in templates by default
Switch to allowing missing keys in jsonpath templates by default.
Add support for allowing/disallowing missing keys in go templates
(default=allow).
Add --allow-missing-template-keys flag to control this behavior (default=true /
allow missing keys).
Fixes#37991
@kubernetes/sig-cli-misc @kubernetes/api-reviewers @smarterclayton @fabianofranz @liggitt @pwittrock
Automatic merge from submit-queue (batch tested with PRs 39648, 38167, 39591, 39415, 39612)
Add hack/verify-readonly-packages.sh
Create a `.readonly` file in a package. Any change between `$KUBE_VERIFY_GIT_BRANCH` and `HEAD` will lead to output like:
```shell
$ hack/verify-readonly-packages.sh
Readonly packages changed compared to "master" branch: pkg/generated
```
This is part of https://github.com/kubernetes/kubernetes/issues/39528
Automatic merge from submit-queue (batch tested with PRs 39628, 39551, 38746, 38352, 39607)
Increasing times on reconciling volumes fixing impact to AWS.
#**What this PR does / why we need it**:
We are currently blocked by API timeouts with PV volumes. See https://github.com/kubernetes/kubernetes/issues/39526. This is a workaround, not a fix.
**Special notes for your reviewer**:
A second PR will be dropped with CLI cobra options in it, but we are starting with increasing the reconciliation periods. I am dropping this without major testing and will test on our AWS account. Will be marked WIP until I run smoke tests.
**Release note**:
```release-note
Provide kubernetes-controller-manager flags to control volume attach/detach reconciler sync. The duration of the syncs can be controlled, and the syncs can be shut off as well.
```
gzip output is not stable between go releases, so bindata.go shows spurious diffs when compressed
also, half the output is human readable, and the other half is already zip compressed
Switch to allowing missing keys in jsonpath templates by default.
Add support for allowing/disallowing missing keys in go templates
(default=allow).
Add --allow-missing-template-keys flag to control this behavior
(default=true / allow missing keys).
Automatic merge from submit-queue
add import cycle checking for staging to verify scripts
Adds an import cycle check to verify scripts since we can't yet use import-boss. See https://github.com/kubernetes/gengo/pull/27 for details, but since the rule is very simple and global, this ought to provide sufficient protection.
@kubernetes/sig-api-machinery-misc
Automatic merge from submit-queue (batch tested with PRs 36229, 39450)
Bump etcd to 3.0.14 and switch to v3 API in etcd.
Ref #20504
**Release note**:
```release-note
Switch default etcd version to 3.0.14.
Switch default storage backend flag in apiserver to `etcd3` mode.
```
Automatic merge from submit-queue
Adding test-federation-cmd.sh to test kubectl with federation apiserver
There are 2 parts to the PR:
* Adding ability to run kubectl tests for a subset of resources.
* Adding test-federation-cmd.sh that runs kubectl tests for resources that are supported by federation-apiserver.
cc @kubernetes/sig-federation @kubernetes/sig-api-machinery
```release-note
Adding kubectl tests for federation
```
Automatic merge from submit-queue (batch tested with PRs 39405, 39371)
hack/local-up-cluster.sh: fix typo in error message
This commit fixes typo in error message and also removes stale comment from `hack/local-up-cluster.sh`.
Automatic merge from submit-queue (batch tested with PRs 39022, 39331, 39070, 39344)
Add a build rule for the boilerplate unit test.
We recently added unit tests that just run whenever you run `hack/verify_boilerplate.sh`, which really isn't the right time to do that. This adds a build rule instead.
Automatic merge from submit-queue
Begin paths for internationalization in kubectl
This is just the first step, purposely simple so we can get the interface correct.
@kubernetes/sig-cli @deads2k
Automatic merge from submit-queue (batch tested with PRs 36751, 38968)
Convert * users/groups to system:authenticated group in ABAC
Part of enabling anonymous auth by default in 1.6 means protecting earlier policies that did not intend to grant access to anonymous users.
This modifies ABAC policies that match `user` or `group` `*` to only match authenticated users.
Docs PR to update examples to use `system:authenticated` or `system:unauthenticated` groups explicitly: https://github.com/kubernetes/kubernetes.github.io/pull/1992
```release-note
ABAC policies using "user":"*" or "group":"*" to match all users or groups will only match authenticated requests. To match unauthenticated requests, ABAC policies must explicitly specify "group":"system:unauthenticated"
```
Automatic merge from submit-queue
create kuberentes-discovery image
Creates an image for `kubernetes-discovery` since this is the API registration, aggregation, and proxy image.
Automatic merge from submit-queue
Coreos kube-up now with less cloud init
This update includes significant refactoring. It moves almost all of the
logic into bash scripts, modeled after the `gci` cluster scripts.
The reason to do this is:
1. Avoid duplicating the saltbase manifests by reusing gci's parsing logic (easier maintenance)
2. Take an incremental step towards sharing more code between gci/trusty/coreos, again for better maintenance
3. Pave the way for making future changes (e.g. improved rkt support, kubelet support) easier to share
The primary differences from the gci scripts are the following:
1. Use of the `/opt/kubernetes` directory over `/home/kubernetes`
2. Support for rkt as a runtime
3. No use of logrotate
4. No use of `/etc/default/`
5. No logic related to noexec mounts or gci-specific firewall-stuff
It will make sense to move 2 over to gci, as well as perhaps a few other small improvements. That will be a separate PR for ease of review.
Ref #29720, this is a part of that because it removes a copy of them.
Fixes#24165
cc @yifan-gu
Since this logic largely duplicates logic from the gci folder, it would be nice if someone closely familiar with that gave an OK or made sure I didn't fall into any gotchas related to that, so cc @andyzheng0831
Automatic merge from submit-queue (batch tested with PRs 38426, 38917, 38891, 38935)
Remove cluster/mesos from hack/verify-flags/exceptions.txt
`cluster/mesos` scripts was removed; so remove it from `hack/verify-flags/exceptions.txt`.
The diff was generated by `hack/verify-flags-underscore.py -e > hack/verify-flags/exceptions.txt`.
Automatic merge from submit-queue
Curating Owners: hack/jenkins
cc @rmmh @spxtr @ixdy @fejta
In an effort to expand the existing pool of reviewers and establish a
two-tiered review process (first someone lgtms and then someone
experienced in the project approves), we are adding new reviewers to
existing owners files.
If You Care About the Process:
------------------------------
We did this by algorithmically figuring out who’s contributed code to
the project and in what directories. Unfortunately, that doesn’t work
well: people that have made mechanical code changes (e.g change the
copyright header across all directories) end up as reviewers in lots of
places.
Instead of using pure commit data, we generated an excessively large
list of reviewers and pruned based on all time commit data, recent
commit data and review data (number of PRs commented on).
At this point we have a decent list of reviewers, but it needs one last
pass for fine tuning.
Also, see https://github.com/kubernetes/contrib/issues/1389.
TLDR:
-----
As an owner of a sig/directory and a leader of the project, here’s what
we need from you:
1. Use PR https://github.com/kubernetes/kubernetes/pull/35715 as an example.
2. The pull-request is made editable, please edit the `OWNERS` file to
remove the names of people that shouldn't be reviewing code in the
future in the **reviewers** section. You probably do NOT need to modify
the **approvers** section. Names asre sorted by relevance, using some
secret statistics.
3. Notify me if you want some OWNERS file to be removed. Being an
approver or reviewer of a parent directory makes you a reviewer/approver
of the subdirectories too, so not all OWNERS files may be necessary.
4. Please use ALIAS if you want to use the same list of people over and
over again (don't hesitate to ask me for help, or use the pull-request
above as an example)
Automatic merge from submit-queue (batch tested with PRs 38525, 38977)
add service status detection to kubernetes-discovery
This adds an inspection of services and endpoints before adding the APIService to kubernetes-discovery. This keeps a single bad API service from killing old clients since proxying will fail.
Automatic merge from submit-queue
conversion-gen: add --skip-unsafe flag
We should expose the SkipUnsafe option, for legacy compatability, so
that conversion-go can be used in other projects, and for platforms
where unsafe is not available.
Make unsafe code generation the default though, and have the help text
hint that the resulting code is sub-optimal.
Automatic merge from submit-queue (batch tested with PRs 37468, 36546, 38713, 38902, 38614)
Remove extensions/v1beta1 Job
Fixes https://github.com/kubernetes/kubernetes/issues/32763. This endpoint was deprecated in 1.5 and was planned to be removed in 1.6.
**Release note**:
```release-note
Remove extensions/v1beta1 Jobs resource, and job/v1beta1 generator.
```
Automatic merge from submit-queue (batch tested with PRs 37468, 36546, 38713, 38902, 38614)
local-up-cluster additions
**What this PR does / why we need it**:
Changes to local-cluster-up: These include: 1) a simple additional help option. 2) additional error message to not being able to run `docker ps`. 3) fail faster when etcd is not found in path. Hopefully these make developing a bit more pleasant.
**Release note**:
```NONE
```
Automatic merge from submit-queue (batch tested with PRs 38888, 38895)
Bundle federation/develop directory in the test tarball for federation testing.
cc @kubernetes/sig-federation-misc
Automatic merge from submit-queue
use in-cluster kubeconfig for genericapiserver
Allow the use of the in-cluster config to communicate with the core API server for delegated authn/authz for an addon API server.
@kubernetes/sig-api-machinery @sttts
from etcd.sh split the start process into validate fucntion + start function so that the validate piece can be reused elsewhere. the up-cluster script has been changed to remove duplicate docker logic to the one used in buid-tools/common.sh and the validate etcd function is now used here.
moved docker daemon check function to util.sh and made function name changes and upstream changes.
The current dev-build-*.sh scripts do a full release build which means
running tests and also doing cross-platform builds. This is unnecessary
and after discussing this in Slack it was suggested to either blow away
these files or fix them. This should fix them.
Automatic merge from submit-queue (batch tested with PRs 38783, 36396)
hack/cherry_pick_pull.sh: cleanup patch files
this was driving me nuts.
it will now remove the patch files from /tmp
Automatic merge from submit-queue
Rename root BUILD to BUILD.bazel, and rename build-tools/ back to build/
**What this PR does / why we need it**: undoes #35453. `build-tools/` was intended to be a temporary workaround until https://github.com/bazelbuild/bazel/issues/552 was fixed, which is has been, as of bazel 0.4.1.
**Which issue this PR fixes**: fixes#38126
FYI @thockin
since this is likely to be rebase hell, my list of actions:
```console
$ git mv BUILD BUILD.bazel
$ git commit -a
$ git mv build-tools/ build/
$ sift -l 'build-tools' | xargs sed -i -e 's:build-tools/:build/:g'
$ git checkout HEAD docs/
$ git commit -a
```
Automatic merge from submit-queue (batch tested with PRs 37708, 34410)
Add restclientconfig helper fn for parsing timeout
Related downstream PR: https://github.com/openshift/origin/pull/12062 (example of use-case for this patch)
**Release note**:
```release-note
release-note-none
```
This patch adds a package `pkg/client/unversioned/clientcmd/util` and
defines a `ParseTimeout` helper function for parsing time from a
user-defined string. This allows code re-use in other packages that
require the creation of a new restclient (and therefore must set the
`--global-timeout` flag value manually).
@fabianofranz @kubernetes/cli-review
Automatic merge from submit-queue (batch tested with PRs 38154, 38502)
Rename "release_1_5" clientset to just "clientset"
We used to keep multiple releases in the main repo. Now that [client-go](https://github.com/kubernetes/client-go) does the versioning, there is no need to keep releases in the main repo. This PR renames the "release_1_5" clientset to just "clientset", clientset development will be done in this directory.
@kubernetes/sig-api-machinery @deads2k
```release-note
The main repository does not keep multiple releases of clientsets anymore. Please find previous releases at https://github.com/kubernetes/client-go
```
Automatic merge from submit-queue (batch tested with PRs 38727, 38726, 38347, 38348)
Second pass of renaming kube-dns configure files
Continue work of #38523.
Not sure why cluster/centos/deployAddons.sh was omitted in previous PR. Also deletes the non-use `DNS_REPLICAS` var and changes `-rc` suffix in hack/local-up-cluster.sh.
@thockin @bowei @deads2k
Automatic merge from submit-queue (batch tested with PRs 35436, 37090, 38700)
Significantly speed-up make
- do not call `dirname` for every go file => gives **>8 seconds** on each make run
- do not preserve time during rsync from `_output/local/go/bin` to `_output/local/bin/<os>/<arch>`:
We do a touch after our rebuild heuristic triggers.
If in `_output/local/go/bin` you have an older binary and go decides that it's good enough, the following rsync will "preserve the timestamp" of the binary copy in `_output/local/bin/<os>/<arch>`. This reverts the effect of any previous `touch` (compare `Makefile.generated_files`).
We do a complete rsync of binaries for each go target, not only the one which is rebuilt. This means that later go targets will overwrite the timestamps of freshly touched binaries. Hence, our rebuild heuristic will trigger again and again when running `make`.
This PR remove the "preserve mtime" from the rsync call. Hence, the effect of touch is not reverted anymore by later rsyncs.
Automatic merge from submit-queue (batch tested with PRs 38315, 38624, 38572, 38544)
Fix code coverage in build script on OS X.
Fixes#20223
- Fixes code coverage in build script on BSD systems (including OS X).
- Supersedes #38536.
Successfully tested on two platforms:
```
Darwin <hostname> 16.1.0 Darwin Kernel Version 16.1.0: Thu Oct 13 21:26:57 PDT 2016; root:xnu-3789.21.3~60/RELEASE_X86_64 x86_64
```
```
Linux <hostname> 4.4.14-040414-generic #201606241434 SMP Fri Jun 24 18:36:45 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
```
cc @ixdy @mfanjie @balajismaniam @smarterclayton @soltysh
**Release note**:
```release-note
```
Automatic merge from submit-queue (batch tested with PRs 38315, 38624, 38572, 38544)
kubernetes-discovery proxy
The last commit adds an authenticating (but not authorizing) proxy to `kubernetes-discovery`. The other commits are in the submit queue already.
@sttts @cjcullen This is it. After this we can start e2e wiring.
Automatic merge from submit-queue
Leak filling for newline format on benchmark-go.sh
**What this PR does / why we need it**: make hack/benchmark-go.sh work
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
**Special notes for your reviewer**: First commit :D , did I make a wrong modification?
**Release note**:
```release-note
```
Automatic merge from submit-queue
goflags must be after subcommand
**What this PR does / why we need it**:
if GOFLAGS is set when calling make, kubernetes will fail to build
as an example, I often have `GOFLAGS=-v` so I can have some idea of progress during compilation
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*:
no known issue
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue (batch tested with PRs 38277, 36361, 38452)
local-up: resolve sudo -E'd paths better
This problem won't affect everyone, but for people who have `--with-secure-path` configured for their sudo binaries, `sudo -E` won't actually preserve PATH, which means the sub-bash won't necessarily be able to find the binary which `test` found to exist.
This fixes that.
Ubuntu [used to](https://bugs.launchpad.net/ubuntu/+source/sudo/+bug/50797) configure it that way, and they might still.
It's configured as such on my (Gentoo) machine.
Automatic merge from submit-queue (batch tested with PRs 38277, 36361, 38452)
Add options for build container rsync optimization
KUBE_RSYNC_COMPRESS env var sets rsync compression level.
KUBE_RSYNC_GENERATED_TO_BUILD_CONTAINER env var disables rsyncing
generated files to build containers.
Why KUBE_RSYNC_COMPRESS is needed -- from rsync manual on `--compress` option (implied by non-zero `--compress-level`):
> Note that this option typically achieves better compression ratios than can be achieved by using a compressing remote shell or a compressing transport because it takes advantage of the implicit information in the matching data blocks that are not explicitly sent over the connection.
Use case for `KUBE_RSYNC_GENERATED_TO_BUILD_CONTAINER`: when you sometimes build stuff locally (e.g. `make WHAT=cmd/kubectl`) and sometimes do it on remote docker (`build-tools/run.sh make WHAT=cmd/hyperkube`), local builds touch generated files which causes them to be rsynced to the build data container, which may slow down the builds. Still, I'm not sure whether local->remote rsync of generated files is useful (e.g. someone may want to edit generated files for debugging purposes?), so I made not rsyncing these files an option instead of forcing such behavior.