Automatic merge from submit-queue (batch tested with PRs 36263, 36755, 37357, 37222, 37524)
kubeadm: Implement support for symbolic labels in --use-kubernetes-version
**What this PR does / why we need it**: This patch adds "stable", "latest" and other labels as valid versions in "kubeadm init --use-kubernetes-version" flag.
Now, defaults can be pointing to "stable" and users will always get
latest available stable build of Kubernetes via kubeadm.
There is no need anymore to hardcode version string inside kubeadm
binary.
It is also possible to use labels like "latest" or point to exact
branch: "stable-1.4"
**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**:
**Release note**:
```release-note
- kubeadm init --use-kubernetes-version now understands "stable","latest", "stable-1.4" and other labels as valid version. It will fetch actual build number from release servers.
```
Now, defaults can be pointing to "stable" and users will always get
latest available stable build of Kubernetes via kubeadm.
There is no need anymore to hardcode version string inside kubeadm
binary.
It is also possible to use labels like "latest" or point to exact
branch: "stable-1.4"
Previously, GetEnvParams (now called SetEnvParams) had no way of being altered unless
it was through enviroment variables. These changes allow for a global
EnvParam to be set and also altered while still initally getting their value from
set enviroment variables. This change is especially helpful for testing
(see kubeadm/app/util/kubeconfig_test.go).
Includes checks for verifying services exist and are enabled, ports are
open, directories do not exist or are empty, and required binaries are
in the path.
Checks that user running kubeamd init and join is root and will only execute
command if user is root. Moved away from using kubectl error handling to
having kubeadm handle its own errors. This should allow kubeadm to have
more meaningful errors, exit codes, and logging for specific kubeadm use
cases.
Kubernetes Submit Queue