Use "volume.beta.kubernetes.io/storage-class" for the MySQL pvc if the storage type is specified

[andrewhowdencom]

Hallo,

Using MySQL to organise some local development stuff. The cluster version running locally is hyperkube v1.4.4, and doesn't like volume.alpha.kubernetes.io/storage-class:default so much. I cannot seem to just provision the asspciated pv and just have them find each other and resolve, instead I find:

$ kubectl describe pvc
Name:		magento-prometheus-mysql
Namespace:	default
Status:		Pending
Volume:		
Labels:		<none>
Capacity:	
Access Modes:	
Events:
  FirstSeen	LastSeen	Count	From				SubobjectPath	Type		Reason			Message
  ---------	--------	-----	----				-------------	--------	------			-------
  3m		4s		14	{persistentvolume-controller }			Warning		ProvisioningFailed	cannot find volume plugin for alpha provisioning

Prometheus appears to solve this by specifying volume.alpha.kubernetes.io/storage-class:default class if the user doesn't indicate a storage class, and volume.beta.kubernetes.io/storage-class:{{ .Values.storagClass}} if the user does. Using the beta storage class attribute allows me to just create the PVs locally so I can hack on stuff. It also might help with other people not running k8s in non-standard environments.

I suggest a similar approach be taken for MySQL, and perhaps documented somewhere? I can get a PR up today if someone says "LGTM" in the next couple hours, though I don't understand it well enough to test it thoroughly.

Ref: https://github.com/kubernetes/charts/blob/19f85b0bc2b500691e4707f54f25302138f050da/stable/prometheus/templates/alertmanager-pvc.yaml#L6-L10

Edits: I am trying this. Interestingly, it's not working. Rendering badly for some reason
More edits: That prometheus example doesn't seem to be using chomp properly The - operator needs to be behind the else, I think.

Not yet good enough for a PR (need to adjust the values.yaml to explain things), but seems to work:

master...littlemanco:ahowden_make-mysql-user-beta-storage-class#diff-918808a355911deb9ce5a723c449a669R7

[prydonius]

@andrewhowdencom only just saw this, I dropped #255 yesterday which updates all the charts to use the same approach as Prometheus (and fixes the formatting in Prometheus). See the discussion in #116 also.

[andrewhowdencom]

Awesome! I probably should have found that issue initially. I'll close this as a dupe of that issue, and subscribe to that pull request.

Thanks man!