Add option for Azure cross subscription backups

[boxcee]

Closes #1646

[skriss]

Thanks for this @boxcee! I'll review and do some testing this week.

[skriss]

@boxcee thanks again for this PR! Have you been able to test this? I don't currently have an Azure cluster set up so trying to decide if I need to for testing or not.

Let's also document the subscriptionId config key at site/docs/master/api-types/backupstoragelocation.md, under the Azure section.

[boxcee]

@skriss For testing, is there anything I should document? We have an Azure account and I will test this today.

[skriss]

@boxcee just some quick notes on exactly what scenario/steps you tested would be great - don't need anything long, just enough to get the idea. thanks!

[skriss]

code LGTM - just waiting for confirmation on testing

[boxcee]

Soooo, I did test this and it does work. But, please don't review just yet. During testing I realized that I also need to store snapshots in a different subscription.

I was testing this today but couldn't finish it. Will continue on Monday and update PR.

[jweldonca]

hey @boxcee, how do you test this succesfully?

I get the following error
An error occurred: some backup storage locations are invalid: error getting backup store for location "default": rpc error: code = Unknown desc = config has invalid keys [subscriptionId]; valid keys are [resourceGroup storageAccount bucket prefix]

[boxcee]

@jweldonca I assume this error shows up in the controller?

By default the Makefile creates a new container when run with all-containers. I changed the repository to point to our company repository and docker pushed the images there.
Then I also modified the deployment (after installing with velero install) to point to the company repo.

Your problem is basically that you have built a new velero binary, but the images being deployed are still the master images.

For reference: https://github.com/heptio/velero/blob/2d845683a2ddf06b956433ff57e04b86890f4776/pkg/install/deployment.go#L96

[boxcee]

@skriss Can confirm it does work cross-subscription now!

1. Created a cluster in subscription A and configured it to create snapshots and backups in subscription B.
2. Used the example nginx-app to create a backup.
3. Deleted the cluster in subscription A.
4. Re-created a cluster in subscription A and configured it as before to use subscription B for snapshots and backups.
5. Then I ran the restore command from the example.
6. Success!

[skriss]

👍 I didn't realize that cross-subscription volume snapshots were even possible - sounds great! I'll take another look at the code shortly.

[skriss]

LGTM. @carlisia - is it going to be an issue for you if we merge this Azure-specific PR into master now? If yes and you want to hold it until the separate plugin repo is created, then we'll want to help migrate the PR over there.

[carlisia]

It'd be best to merge now wrt the plugins!

Great contribution, thank you!