Helm Chart add support `extraVolumes` and `extraVolumeMounts`

[frantjc]

Is your feature request related to a problem?/Why is this needed

I would like to be able to inject custom CA certs into the azure-disk-csi containers when installing it with the Helm chart without maintaining my own custom versions of the azure-disk-csi container images.

Describe the solution you'd like in detail

Allow passing extraVolumes and extraVolumeMounts to the Helm Chart via a values file.

Describe alternatives you've considered

I could build and maintain by own custom versions of the azure-disk-csi container images, but that is cumbersome.

Additional context

I'd be open to doing this myself, but it is unclear to me which Helm Chart's templates I'd make the changes in.

[andyzhangx]

@frantjc does following mount path contains your custom certs?

azuredisk-csi-driver/charts/latest/azuredisk-csi-driver/templates/csi-azuredisk-node.yaml

Lines 219 to 228 in 005760c

	{{- if or (eq .Values.cloud "AzureStackCloud") (eq .Values.linux.distro "fedora") }}
	- name: ssl
	mountPath: /etc/ssl/certs
	readOnly: true
	{{- end }}
	{{- if eq .Values.linux.distro "fedora" }}
	- name: ssl-pki
	mountPath: /etc/pki/ca-trust/extracted
	readOnly: true
	{{- end }}

[frantjc]

@andyzhangx yes, it does! I have a couple of follow-up questions:

• I'm seeing that mount path only gets added to 2 of the containers. Do the other containers' processes just not reach outside of the cluster?
• I see that the condition eq .Values.cloud "AzureStackCloud" has an additional side-effect on the AZURE_ENVIRONMENT_FILEPATH environment variable. Would that cause azure-disk-csi to function incorrectly outside of Azure Stack?

[andyzhangx]

@andyzhangx yes, it does! I have a couple of follow-up questions:

• I'm seeing that mount path only gets added to 2 of the containers. Do the other containers' processes just not reach outside of the cluster?
• I see that the condition eq .Values.cloud "AzureStackCloud" has an additional side-effect on the AZURE_ENVIRONMENT_FILEPATH environment variable. Would that cause azure-disk-csi to function incorrectly outside of Azure Stack?

@frantjc other sidecar containers do not need custom certs, and you could just use .Values.linux.distro "fedora"

[andyzhangx]

btw, what is your node image distro? @frantjc

[frantjc]

@andyzhangx Ubuntu, which is why using .Values.linux.distro="fedora" doesn't work out of the box since /etc/pki/ca-trust/extracted doesn't exist by default. I've added it manually for now as a workaround.