Move snapshot code to Vm in service model.

[lfu]

The snapshot code in automate was moved from VmOrTemplate to VMware specific class by PR #3707 when VMware was the only class that supported snapshot.

But snapshot support has been added to RHEVM and Openstack as of version Euwe.
The snapshot code in automate should be made available at Vm level.

Links

https://bugzilla.redhat.com/show_bug.cgi?id=1395175

cc @gmcculloug @mkanoor

[gmcculloug]

@lfu You are now exposing these methods on every VM/Template which is not valid in a lot of cases. Before it was only exposed on VMs from automate and I think we should keep it at that level, just move it into the base VM service model.

Also, we should raise an error for providers where we do not support snapshot features with a "Feature not supported" error message.

@durandom I see there is a supports_snapshots? method. Are there granular checks we can use for the different operations?

For example, VMware supports create_snapshot, remove_all_snapshots, remove_snapshot and revert_to_snapshot. RHEV supports all except remove_all_snapshots. It would be nice to raise the proper error message based on the supports logic.

[gmcculloug]

This does not provide any feedback to the caller if snapshots are not supported on the provider. Since we are moving from a specific provider implementation to a generic VM one we should add a call at the top of this method to raise an error if not supported.

LIke this (also address rubocop issues):

def snapshot_operation(task, options = {})
  raise "#{task} operation not supported for #{self.class.name}" unless @object.supports_snapshots?

  options[:ids]  = [id]
  options[:task] = task.to_s
  Vm.process_tasks(options)
end

[durandom]

For example, VMware supports create_snapshot, remove_all_snapshots, remove_snapshot and revert_to_snapshot. RHEV supports all except remove_all_snapshots. It would be nice to raise the proper error message based on the supports logic.

I guess we would have to add all operations as features and then ask the Vm if it supports that operation. So far I only see snapshot features for openstack cloud_volumes and rh vms.

❯ git --no-pager grep -E 'supports(_not)? :.*snapshot'
app/models/manageiq/providers/openstack/cloud_manager/cloud_volume.rb:  supports :snapshot_create
app/models/manageiq/providers/redhat/infra_manager/vm/operations/snapshot.rb:    supports :snapshots do

[gmcculloug]

@lfu Please review failing tests

[lfu]

@miq-bot add_label automate, bug, euwe/yes

[miq-bot]

Checked commit lfu@3569ecf with ruby 2.2.5, rubocop 0.37.2, and haml-lint 0.16.1
4 files checked, 3 offenses detected

lib/miq_automation_engine/service_models/miq_ae_service_vm.rb

• ❗ - Line 13, Col 92 - Style/DoubleNegation - Avoid the use of double negation (!!).

spec/lib/miq_automation_engine/service_methods/miq_ae_service_manageiq-providers-vmware-infra_manager-vm_spec.rb

• ❗ - Line 1, Col 1 - Style/FileName - Use snake_case for source file names.
• ❗ - Line 1, Col 8 - Style/ClassAndModuleCamelCase - Use CamelCase for classes and modules.

[gmcculloug]

Thanks @durandom. That seems outside of the scope of this PR so I am going to merge this and we can look into adding individual snapshot method checks later.

[simaishi]

Euwe backport details:

$ git log -1
commit 4547649a00d3b6d2e49cb31aac957548c01def32
Author: Greg McCullough <[email protected]>
Date:   Mon Nov 21 12:17:23 2016 -0500

    Merge pull request #12726 from lfu/ae_snapshot_1395175
    
    Move snapshot code to Vm in service model.
    (cherry picked from commit eef649356ad7bf8742b3494ea69f71fba5d82a73)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1399207