Packer v1.4.0 released

[me...@hashicorp.com]

Hello Packer community,

We're glad to announce that Packer v1.4.0 is out!

As usual, the changelog contains most of what happened; you can get all the details at

https://github.com/hashicorp/packer/blob/master/CHANGELOG.md#140-april-11-2019

Here are a couple of highlights:

* It is now possible to recursively interpolate variables.

* Windows Containers for Docker for Windows is now supported.

* It is now possible to set a timeout on provisioning steps.

* There is now a new sleep provisioner.

There are a couple of backwards-incompatible changes to the option names in the Amazon, Scaleway, and Hyper-V builders. Template changes can be automatically applied using "packer fix". For more details, check the changelog at https://github.com/hashicorp/packer/blob/master/CHANGELOG.md#backwards-incompatibilities

For plugin developers:

* Most parts of packer are now context cancellable. This is a breaking change,

but we hope this will make cancellation simpler and more idiomatic in most

cases. No more cancel method that cancels an internal context or chan.

As always, let us know via GitHub or this mailing list if you come across any issues.

Have a great day!

Thanks,

The Packer Team