In AWS we can derive the `VpcId` and AZ from the `SubnetId`, so now we do. In the config you can now only specify the `SubnetId`.
This fixes issue #4693.
As pointed out in the initial code review of #4351, some of the steps
from the standard EBS builder were (intetionally) omitted. It turns out
that these actually are useful, and the original rationale for the
omission was wrong. Consequently, this commit adds in the following
steps:
- `StepPrevalidate`
- `StepTagEBSVolumes`
- `StepDeregisterAMI`
- `StepCreateEncryptedAMICopy`
- `StepAMIRegionCopy`
- `StepModifyAMIAttribute`
- `StepCreateTags`
We also fix the interpolation filter and documentation to reflect these
additions, though the majority were already documented and just not
functional.
This commit adds a new type of builder which builds an AMI based on a
snapshot of an EBS volume which is provisioned on a "surrogate"
instance. This can be used to build operating system images from
scratch, but unlike the `chroot` builder does not require running from
an AWS EC2 instance.
