* removed packer.Cache and references since packer.Cache is never used except in the download step. The download step now uses the new func packer.CachePath(targetPath) for this, the behavior is the same.
* removed download code from packer that was reimplemented into the go-getter library: progress bar, http download restart, checksuming from file, skip already downloaded files, symlinking, make a download cancellable by context.
* on windows if packer is running without symlinking rights and we are getting a local file, the file will be copied instead to avoid errors.
* added unit tests for step_download that are now CI tested on windows, mac & linux.
* files are now downloaded under cache dir `sha1(filename + "?checksum=" + checksum) + file_extension`
* since the output dir is based on the source url and the checksum, when the checksum fails, the file is auto deleted.
* a download file is protected and locked by a file lock,
* updated docs
* updated go modules and vendors
This option allows to set the extension of the ISO file after download.
Defaults to "iso". It makes sense for building Mac OS X guests, where the
bootable image is actually a DMG, not an ISO.
In particular, it is important for "parallels-iso" builder to set the right extension.
When debugging a build (or maintaining an existing packer file), teach `packer build -debug` how to step through individual `boot_command`s in order to triage the packer file.
Prevalidates hardware resources on Linux platforms for Virtualbox and
VMware builders. This is currently only available on Linux, as enabling
for both Darwin and Windows platforms, relies on cgo bindings that would
prevent effective cross-compilation.
Packer will now fail to build and validate templates if the template is
requesting that the VM to be created would allocate more system
resources than the host system has available.
This _however_ doesn't catch parallel builds that overflow the hosts
resources, will probably still need a better error message for VM's
failing to boot in that case.
Example Outputs:
```
$ $GOPATH/bin/packer build -debug ./vmware-iso.json
Debug mode enabled. Builds will not be parallelized.
vmware-iso output will be in this color.
2 error(s) occurred:
* Unavailable Resources: RAM - Requested - 204800000MB - Available 21721MB
* Unavailable Resources: Disk - Requested - 4000000000MB - Available 76701MB
```
```
$ $GOPATH/bin/packer build -debug ./vbox-iso.json
Debug mode enabled. Builds will not be parallelized.
virtualbox-iso output will be in this color.
2 error(s) occurred:
* Unavailable Resources: RAM - Requested - 10240000MB - Available 21721MB
* Unavailable Resources: Disk - Requested - 1000000000MB - Available 76701MB
```
Adrien Delorme
Vadym Haidamaka
Megan Marsh
Stephen Fox
Andrew Pennebaker
Ali Rizvi-Santiago
Adrien Delorme
Matthew Hooker
Ben Phegan
Ben Phegan
Rickard von Essen
DanHam
Mikhail Zholobov
Arthur Burkart
Ed Overton
Mike Stankavich
Orivej Desh
Lamoni Finlayson
Ricard Clau
Ian Duffy
Sean Chittenden
Chris Bednarski
Jake Champlin
Mark Peek