593 feature

[shivdudhani]

Using a pointer to a boolean to handle default:

• As the defaulting is done by mutating webhook if the policy was created when the webhook was not active, we will have value nil.
• the nil has been handled in code, where it is used. So if the value is nil, we skip background processing as it missed the policy mutation webhook.
• this will be a downside of using a pointer instead of variable, as additional checks are needed.

@realshuting , as this was limiting some issues for others, Those can now be resolved now.

Also implements condition and variable support.
** To be merged after #587 *

fixes https://github.com/nirmata/kyverno/issues/595
fixes https://github.com/nirmata/kyverno/issues/593
fixes https://github.com/nirmata/kyverno/issues/592

[shivdudhani]

To be merged after https://github.com/nirmata/kyverno/pull/587

[shivdudhani]

@JimBugwadia we currently can use generate on any resources. But can only support re-evaluation of policy on resource update for Namespace resource.

[shivdudhani]

If the key is not present in context, the variable is set to nil. We are currently awaiting https://github.com/nirmata/kyverno/issues/568 to understand how to handle null values. As the type is unknown during variable substitution.