Native disk update

[s4heid]

Summary

This change introduces a new cloud method called update_disk, which can be used to update disk parameters on an existing Azure Disk. Disk size and storage account type can be changed on any data disk. For storage account types PremiumV2_LRS and Ultra Disks, iops and throughput (mbps) can also be changed.

Relates to: cloudfoundry/bosh#2496

Checklist:

Please check each of the boxes below for which you have completed the corresponding task:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• All unit tests pass locally (after my changes)
• Rubocop reports zero offenses (after my changes) -- there is a complexity violation in the disk manager. either we disable the check for the method or we can discuss if you prefer a different solution.

Please include below the summary portions of the output from the following 2 scripts:

pushd src/bosh_azure_cpi
  ./bin/test-unit
  ./bin/rubocop_check
popd

NOTE: Please see how to setup dev environment and run unit tests in docs/development.md.

Unit Test output:

Finished in 6.62 seconds (files took 0.73321 seconds to load)
1044 examples, 0 failures

Integration Test output:

$ bundle exec rspec ./spec/integration
...
Finished in 1 minute 17.39 seconds (files took 0.43431 seconds to load)
3 examples, 0 failures

Rubocop output:

Inspecting 190 files
.......C........................................C.............................................................................................................................................

Offenses:

lib/cloud/azure/disk/disk_manager2.rb:48:5: C: Metrics/ParameterLists: Method has too many optional parameters. [4/3]
    def update_disk(disk_id, size = nil, storage_account_type = nil, iops = nil, mbps = nil) ...
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
lib/cloud/azure/vms/vm_manager.rb:21:5: C: Metrics/AbcSize: Assignment Branch Condition size for create is too high. [<87, 178, 53> 205.1/192]
    def create(bosh_vm_meta, location, vm_props, disk_cids, network_configurator, env, agent_settings, network_spec, config) ...
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
lib/cloud/azure/vms/vm_manager.rb:21:5: C: Metrics/CyclomaticComplexity: Cyclomatic complexity for create is too high. [45/39]
    def create(bosh_vm_meta, location, vm_props, disk_cids, network_configurator, env, agent_settings, network_spec, config) ...
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
lib/cloud/azure/vms/vm_manager.rb:21:5: C: Metrics/MethodLength: Method has too many lines. [189/184]
    def create(bosh_vm_meta, location, vm_props, disk_cids, network_configurator, env, agent_settings, network_spec, config) ...
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
lib/cloud/azure/vms/vm_manager.rb:21:5: C: Metrics/PerceivedComplexity: Perceived complexity for create is too high. [50/45]
    def create(bosh_vm_meta, location, vm_props, disk_cids, network_configurator, env, agent_settings, network_spec, config) ...
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

190 files inspected, 5 offenses detected

Changelog

• The update_disk cloud method has been introduced, allowing updates to disk parameters for Azure Disks, including disk size and storage account type. For PremiumV2_LRS and Ultra Disks, IOPS and throughput (mbps) adjustments are now possible.

[aramprice]

This seems good from a structural perspective. I don't have much context on the Azure internals so it may be helpful to have input from others who have more Azure experience.

[MSSedusch]

lgtm

[rkoster]

Thanks! @s4heid