Support `--version` flag

[ialidzhikov]

trafficstars

/sig storage /kind feature

What would you like to be added:

It is idiomatic and a wide practice a component/binary to have a --version flag:

$ docker run k8s.gcr.io/kube-apiserver:v1.18.6 kube-apiserver --version
Kubernetes v1.18.6

$ docker run k8s.gcr.io/kube-apiserver:v1.18.6 kube-apiserver --version=raw
version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.6", GitCommit:"dff82dc0de47299ab66c83c626e08b245ab19037", GitTreeState:"clean", BuildDate:"2020-07-15T16:51:04Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}

$ docker run coredns/coredns:1.7.0 --version
CoreDNS-1.7.0
linux/amd64, go1.14.4, f59c03d

$ docker run mcr.microsoft.com/k8s/csi/azuredisk-csi:v0.8.0 --version
Build Date: "2020-08-10T02:31:06Z"
Compiler: gc
Driver Name: disk.csi.azure.com
Driver Version: v0.8.0
Git Commit: 37a0784fbee9a141fc1bed2d26a1196d664f5d6b
Go Version: go1.13.10
Platform: linux/amd64
Topology Key: topology.disk.csi.azure.com/zone

Currently gcp-compute-persistent-disk-csi-driver does not support such flag:

docker run k8s.gcr.io/cloud-provider-gcp/gcp-compute-persistent-disk-csi-driver:v1.3.4 --version
flag provided but not defined: -version
Usage of /gce-pd-csi-driver:
  -add_dir_header
    	If true, adds the file directory to the header
  -alsologtostderr
    	log to standard error as well as files
  -cloud-config string
    	Path to GCE cloud provider config
  -endpoint string
    	CSI endpoint (default "unix:/tmp/csi.sock")
  -extra-labels string
    	Extra labels to attach to each PD created. It is a comma separated list of key value pairs like '<key1>=<value1>,<key2>=<value2>'. See https://cloud.google.com/compute/docs/labeling-resources for details
  -http-endpoint :8080
    	The TCP network address where the prometheus metrics endpoint will listen (example: :8080). The default is empty string, which means metrics endpoint is disabled.
  -log_backtrace_at value
    	when logging hits line file:N, emit a stack trace
  -log_dir string
    	If non-empty, write log files in this directory
  -log_file string
    	If non-empty, use this log file
  -log_file_max_size uint
    	Defines the maximum size a log file can grow to. Unit is megabytes. If the value is 0, the maximum file size is unlimited. (default 1800)
  -logtostderr
    	log to standard error instead of files (default true)
  -metrics-path /metrics
    	The HTTP path where prometheus metrics will be exposed. Default is /metrics. (default "/metrics")
  -run-controller-service
    	If set to false then the CSI driver does not activate its controller service (default: true) (default true)
  -run-node-service
    	If set to false then the CSI driver does not activate its node service (default: true) (default true)
  -skip_headers
    	If true, avoid header prefixes in the log messages
  -skip_log_headers
    	If true, avoid headers when opening log files
  -stderrthreshold value
    	logs at or above this threshold go to stderr (default 2)
  -v value
    	number for the log level verbosity
  -vmodule value
    	comma-separated list of pattern=N settings for file-filtered logging

Why is this needed:

• Sometimes image SHA can be used instead of human readable tags - in such case the --version flag is useful to understand the component version behind the image SHA.
• The version flag can prove also more metadata for the component - such as GitCommit, BuildDate, GoVersion, Platform.

k8s.io/component-base has useful package (verflag,version) that can be used for this purpose (this pkg is used by the core K8s components as well).

[mattcary]

Sounds reasonable---if you can come up with a PR I'll look at it!

My instinct would be to keep it simple, basically just repeat the same as what is emitted to metrics on startup.

[k8s-triage-robot]

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/lifecycle stale

[ialidzhikov]

/remove-lifecycle stale

[mattcary]

@ialidzhikov again, PRs are welcome.

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/lifecycle stale

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/lifecycle rotten

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
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/close not-planned

[k8s-ci-robot]

@k8s-triage-robot: Closing this issue, marking it as "Not Planned".

In response to this:

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Reopen this issue with /reopen
• Mark this issue as fresh with /remove-lifecycle rotten
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Please send feedback to sig-contributor-experience at kubernetes/community.

/close not-planned

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