Cluster-api: Provide a yaml output format for clusterctl config repositories

[randomvariable]

User Story

As a operator I want to quickly see what $HOME/.cluster-api/clusterctl.yaml looks like after running
clusterctl config cluster --help

Detailed Description

Add a way, and surface via the help information the way to see the embedded clusterctl.yaml so an operator can see the format and override it if they want.

Anything else you would like to add:

[Miscellaneous information that will assist in solving the issue.]

/kind feature

[randomvariable]

Via Slack https://kubernetes.slack.com/archives/C8TSNPY4T/p1582554891002400, the functionality is there in clusterctl config repositories, need to cross-reference in the help and also provide an -o yaml type command

[vincepri]

/help
/milestone Next
/priority important-longterm

[k8s-ci-robot]

@vincepri:
This request has been marked as needing help from a contributor.

Please ensure the request meets the requirements listed here.

If this request no longer meets these requirements, the label can be removed
by commenting with the /remove-help command.

In response to this:

/help
/milestone Next
/priority important-longterm

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.

[jayunit100]

+100

[jayunit100]

This should probably print a warning or fail ? bc i dont have that YAML.

Instead it just said it doesnt have the docker provider.

In general, should we just fail fast if the user hasn't initialized with a providers YAML ?

-  cluster-api git:(master) ✗ bin/clusterctl  config provider --infrastructure=docker
Error: failed to get configuration for the InfrastructureProvider with name docker. Please check the provider name and/or add configuration for new providers using the .clusterctl config file

Provide configuration values to be used for variable substitution when installing providers or creating clusters.

[prankul88]

/assign

[prankul88]

/lifecycle active

[wfernandes]

/area clusterctl

[wfernandes]

@prankul88 Thanks for reaching out regarding this issue.

https://kubernetes.slack.com/archives/C8TSNPY4T/p1582554891002400

So I think the idea here is not necessarily the contents of the $HOME/.cluster-api/clusterctl.yaml but rather from the slack conversation what is being asked for is a YAML formatted output of clusterctl config repositories.

So in this case we don't necessarily need the path of the config file. In my understanding, we need to add a -o yaml flag for clusterctl config repositories and that should print out the repository list which is a []Provider but in yaml format.

https://github.com/kubernetes-sigs/cluster-api/blob/23a9ec341de33c399c542558c22046cb413082d5/cmd/clusterctl/cmd/config_repositories.go#L63

Let me know if this makes sense. Happy to help 🙂

[wfernandes]

@randomvariable Maybe we should retitle this issue to specify the ask from the slack convo. WDYT?

[randomvariable]

Yup sure, retitle how you think best.

[wfernandes]

/retitle Provide a yaml output format for clusterctl config repositories

[prankul88]

@wfernandes Thanks for taking a look :)