Timmy/installer

[timmy-wright]

What type of PR is this?

/kind feature

What this PR does / why we need it:

This PR adds the following functions to node-bootstrapper:

• It produces a kubeconfig or bootstrap-kubeconfig (depending on scenario) for Arc or Azure machines that use the VM (or M)'s MSI as a token to join the cluster.
• It modifies the windows scripts so they will run on a vanilla windows VM (needed for singularity)

To produce variants of kubeconfig, it introduces new config params:

• NodeBootstrappingConfiguration.BootstrappingMethod which can have a string enum value with values below.
• NodeBootstrappingConfiguration.BootstrappingManagedIdentityID to provide a managed identity ID to use to auth to the cluster

const (
	UseArcMsiToMakeCSR        BootstrappingMethod = "UseArcMsiToMakeCSR"
	UseAzureMsiToMakeCSR      BootstrappingMethod = "UseAzureMsiToMakeCSR"
	UseArcMsiDirectly         BootstrappingMethod = "UseArcMsiDirectly"
	UseAzureMsiDirectly       BootstrappingMethod = "UseAzureMsiDirectly"
	UseSecureTLSBootstrapping BootstrappingMethod = "UseSecureTLSBootstrapping"
	//nolint:gosec // this is a const string to use in switch statements, not hardcoded credentials
	UseTLSBootstrapToken BootstrappingMethod = "UseTLSBootstrapToken"
)

The other config params relevant to bootstrapping are:

• NodeBootstrappingConfiguration.KubeletClientTLSBootstrapToken
• NodeBootstrappingConfiguration.EnableSecureTLSBootstrapping

so the new one (being an enum) gives us extensibility in future and is in the same config place as the existing one.

Which issue(s) this PR fixes:

Fixes #

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Special notes for your reviewer:

Release note:

none

[r2k1]

You can check https://pkg.go.dev/os#ExpandEnv for an inspiration (seems like it's not windows friendly).

Do you want to envsubst a single variable or all of them?

[timmy-wright]

Just the one needed to be substituted. Will have a look.

[r2k1]

Avoid using log.Fatal unless absolutely necessary. It exists application immediately, without calling any defer calls or error handling.
We're using different logger.

Also, err2?

[r2k1]

I would do something like

const (
	BootstrappingMethodArcMSI                 BootstrappingMethod = "ArcMSI"
	BootstrappingMethodArcMSIToMakeCSR        BootstrappingMethod = "ArcMSIToMakeCSR"
	BootstrappingMethodAzureMSI               BootstrappingMethod = "AzureMSI"
	BootstrappingMethodAzureMSIToMakeCSR      BootstrappingMethod = "AzureMSIToMakeCSR"
	BootstrappingMethodSecureTLSBootstrapping BootstrappingMethod = "SecureTLSBootstrapping"
	//nolint:gosec // this is a const string to use in switch statements, not hardcoded credentials
	BootstrappingMethodTLSBootstrapToken BootstrappingMethod = "TLSBootstrapToken"
)

[r2k1]

It's probably not BootstrappingMethod, but something like ClusterAuthMethod or KuberentesAuthMethod?