Adds kubeadm subcommands to create, list, and delete bootstrap tokens.
Tokens can be created with a TTL duration, or 0 for tokens that will not
expire. The create command can also be used to specify your own token
(for use when bootstrapping masters and nodes in parallel), or update an
existing token's secret or ttl.
Marked "ex" for experimental for now as the boostrap controllers are not
yet hooked up in core.
Fix boilerplates, comments in the code and make the output of kubeadm more user-friendly
Start using HostPKIPath and KubernetesDir everywhere in the code, so they can be changed for real
More robust kubeadm reset code now.
Removed old glog-things from app.Run()
Renamed /etc/kubernetes/cloud-config.json to /etc/kubernetes/cloud-config since it shouldn't be a json file
Simplification of the code
Less verbose output from master/pki.go
Cleaned up dead code
Start a small logging/output framework:
- fmt.Println("[the-stage-here] Capital first letter of this message. Tell the user what the current state is")
- fmt.Printf("[the-stage-here] Capital first letter. Maybe a [%v] in the end if an error should be displayed. Always ends with \n")
- fmt.Errorf("Never starts with []. Includes a short error message plus the underlying error in [%v]. Never ends with \n")
Automatic merge from submit-queue
New command: "kubeadm token generate"
As part of #33930, this PR adds a new top-level command to kubeadm to just generate a token for use with the init/join commands. Otherwise, users are left to either figure out how to generate a token on their own, or let `kubeadm init` generate a token, capture and parse the output, and then use that token for `kubeadm join`.
At this point, I was hoping for feedback on the CLI experience, and then I can add tests. I spoke with @mikedanese and he didn't like the original propose of `kubeadm util generate-token`, so here are the runners up:
```
$ kubeadm generate-token # <--- current implementation
$ kubeadm generate token # in case kubeadm might generate other things in the future?
$ kubeadm init --generate-token # possibly as a subcommand of an existing one
```
Currently, the output is simply the token on one line without any padding/formatting:
```
$ kubeadm generate-token
1087fd.722b60cdd39b1a5f
```
CC: @kubernetes/sig-cluster-lifecycle
**Release note**:
<!-- Steps to write your release note:
1. Use the release-note-* labels to set the release note state (if you have access)
2. Enter your extended release note in the below block; leaving it blank means using the PR title as the release note. If no release note is required, just write `NONE`.
-->
``` release-note
New kubeadm command: generate-token
```
This surfaces the token generation logic so that users can first
generate and store a token, then pass it to kubeadm init/join.
Otherwise, users have to capture and parse the output of "kubeadm init"
to feed the token to "kubeadm join."
