Run now takes a context as well as a statebag. We'll assign the context
to the blank identifier to prevent namespace collisions. We'll let the
step authors opt-in to using the context.
`find . -iname "step_*.go" -exec gsed -i'' 's/func \(.*\)Run(/func \1Run(_ context.Context, /' {} \;`
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
```
The ISO builders (parallels, qemu, virtualbox, and vmware) had too
much common code which needed to be maintained separately. This change
moves that code to a common ISO configuration.
I exposed TargetPath as a config file option "target_path". I don't like
the name, but it follows the naming convention. The purpose of TargetPath
stands unmodified, and it enables a fair amount of customization.
