adds volume configuration options

[tthebst]

closes #592

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checklist:

• [x ] run make test and make lint
• [x ] test manually (i.e. build/push all images, restart operator, and re-deploy APIs)
• update examples
• [x ] update docs and add any new files to summary.md (view in gitbook after merging)
• cherry-pick into release branches if applicable
• [x ] alert the dev team if the dev environment changed

[deliahu]

@tthebst This is awesome, great job! It's really great how you were able to figure out our conventions and where to put different parts of the code, that must have taken some additional effort, so thank you!

I added some comments, mostly minor. Let me know if you'd like to discuss any of them.

[deliahu]

@tthebst Thanks for addressing my comments!

I merged master in, and made a few small updates to the branch.

I tried creating a cluster with io1 volume types, but it wasn't able to start up. Have you been able to create a cluster with io1 volumes?

I found this error message in my autoscaling group activity history:

Client.InvalidParameterCombination: Could not create volume with size 50GiB and iops 4000 from snapshot 'snap-05048ef88fd5fb0db'

Here's a screenshot:

[deliahu]

Update: I was able to reproduce the issue from the EBS console, and there was a better error message this time :)

I'll add a validation

[deliahu]

LGTM, thanks again for your help on this!

Adding @vishalbollu for a quick review, and then I'll merge it in

[tthebst]

@deliahu Sorry I didn't notice that there was a 50:1 ratio restriction