Automatic merge from submit-queue
Use munged semantic version for side-loaded docker tag
**What this PR does / why we need it**: rather than using the md5sum of the dockerized binary for each side-loaded docker image, use the semantic version (with `+`s replaced with `_`s) for the side-loaded docker images.
The use of the md5sum for the docker tag dates to #6326 2 years ago. I'm not sure why that was chosen, short of it being fairly unique.
My main motivation for changing this is that it makes building the docker images using Bazel's docker rules easier, since the semantic version doesn't depend on the build output.
An added benefit is that the list of images on a running kubernetes cluster is also more straightfoward; rather than a list of opaque, meaningless hexadecimal strings, you get something that indicates the provenance of the image. It'd also be clearer that all of the images came from the same build.
I was able to start a cluster with this change on GCE using both `make quick-release` and `make bazel-release`.
Note that this change has no effect on the tag that's pushed to gcr.io during releases; that's still controlled via `KUBE_IMAGE_DOCKER_TAG`, though we may want to merge this functionality at some point.
@kubernetes/sig-node-pr-reviews is there any reason to stick with using the md5sum strategy? @dchen1107 do you remember why we went with md5sums originally?
cc @spxtr @mikedanese
**Release note**:
```release-note
```
Automatic merge from submit-queue
Support arbitrary alphanumeric strings as prerelease identifiers
**What this PR does / why we need it**: this is basically an extension of #43642, but supports more general prerelease identifiers, per the spec at http://semver.org/#spec-item-9.
These regular expressions are still a bit more restrictive than the SemVer spec allows (we disallow hyphens, and we require the format `-foo.N` instead of arbitrary `-foo.X.bar.Y.bazZ`), but this should support our needs without changing too much more logic or breaking other assumptions.
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue (batch tested with PRs 42379, 42668, 42876, 41473, 43260)
Silence error messages from the docker rmi call we expect to fail
**What this PR does / why we need it**: when we removed `docker tag -f` in #34361 we added a bunch of `docker rmi` calls to preserve behavior for older docker versions. That step is usually a no-op, however, and results in confusing messages like
```
Tagging docker image gcr.io/google_containers/kube-proxy:c8d0b2e7a06b451117a8ac58fc3bb3d3 as gcr.io/kubernetes-release-test/kube-proxy-amd64:v1.5.4
Error response from daemon: No such image: gcr.io/kubernetes-release-test/kube-proxy-amd64:v1.5.4
```
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#42665
**Special notes for your reviewer**: I could probably remove the `docker rmi` calls entirely, though I don't know if folks are still using docker < 1.10. (I think Jenkins still has 1.9.1.)
**Release note**:
```release-note
NONE
```
cc @jessfraz
This update includes significant refactoring. It moves almost all of the
logic into bash scripts, modeled after the `gci` cluster scripts.
The primary differences between the two 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
Maru Newby