update README to add coreos support and kustomize required

[hchenxa]

What this PR does / why we need it:

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

1. Please confirm that if this PR changes any image versions, then that's the sole change this PR makes.

Update the document to add coreos support and kustimize package required.

Release note:

[k8s-ci-robot]

Hi @hchenxa. Thanks for your PR.

I'm waiting for a kubernetes-sigs or kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[hchenxa]

/assign @gyliu513

[jichenjc]

/ok-to-test

[jichenjc]

generate-yaml.sh [options] <path/to/clouds.yaml> <provider os: [centos,ubuntu,coreos]>

this is current grammar

[hchenxa]

seems we need to provide the os cloud, refer below code:

# Check if os cloud is provided
if [[ -n "$2" ]] && [[ $2 != -* ]] && [[ $2 != --* ]]; then
  CLOUD=$2
else
  echo "Error: No cloud specified"
  echo "You mush specify which cloud you want to use."
  echo ""
  print_help
  exit 1
fi

[hchenxa]

I will update the [os name] to [centos,ubuntu,coreos]

[jichenjc]

./generate-yaml.sh clouds.yaml openstack --provideros coreos
Error: No provider OS specified
You must choose between the following operating systems: centos, ubuntu, coreos

root@kvm-017751:/go/src/sigs.k8s.io/cluster-api-provider-openstack/cmd/clusterctl/examples/openstack# ./generate-yaml.sh clouds.yaml openstack coreos
root@kvm-017751:/go/src/sigs.k8s.io/cluster-api-provider-openstack/cmd/clusterctl/examples/openstack#

[hchenxa]

yes, replaced the --provider-os to <provider os>.

[jichenjc]

you may refer to my test result..

[gyliu513]

/approve

/cc @jichenjc @chrigl

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: gyliu513, hchenxa

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [gyliu513]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[jichenjc]

/lgtm