* fix random nil pointer dereference I found while debugging hcl2_upgrade issues
* fix hcl2_upgrade command by creating passthroughs for all text template fields
This adds the new `required_plugins` block to be nested under the packer block.
Example:
```hcl
packer {
required_plugins {
aws = {
version = ">= 2.7.0"
source = "azr/aws"
}
azure = ">= 2.7.0"
}
}
```
For example on darwin_amd64 Packer will install those under :
* "${PACKER_HOME_DIR}/plugin/github.com/azr/amazon/packer-plugin-amazon_2.7.0_x5.0_darwin_amd64"
* "${PACKER_HOME_DIR}/plugin/github.com/hashicorp/azure/packer-plugin-azure_2.7.0_x5.0_darwin_amd64_x5"
+ docs
+ tests
* change beta tag
* remove beta tag from hcl2_upgrade comment
* add a partial to describe the legacy json limitations
* exclude legacy category from templates until it is deployed to the website
* handle template_dir, pwd funcs, handle min_packer_version
* gotpl packer_version becomes hcl2 packer.version
* uuid becomes hcl2 uuidv4
* test code with emojis
* handle all cases were we cannot guess what the argument was
* handle clean_resource_name cases
* up docs
Before change
```
Usage: packer [--version] [--help] <command> [<args>]
Available commands are:
build build image(s) from template
console creates a console for testing variable interpolation
fix fixes templates from old versions of packer
hcl2_upgrade build image(s) from template
inspect see components of a template
validate check that a template is valid
version Prints the Packer version
```
After change
```
Usage: packer [--version] [--help] <command> [<args>]
Available commands are:
build build image(s) from template
console creates a console for testing variable interpolation
fix fixes templates from old versions of packer
hcl2_upgrade transform a JSON template into a HCL2 configuration
inspect see components of a template
validate check that a template is valid
version Prints the Packer version
```
when it encounters map[string]interface{} or []interface{} types, hcl2_upgrade now takes the 'most complex' entry from those in order to tell wether this is going to be a body `body {}` or an attribute `attribute = {}`. Before that the hcl2_upgrade command could be a bit random there.
A way better ( but may be somewhat hard ) way to do this would be to use the actual plugins structs in order to generate the HCL2.
hcl2_upgrade transforms a JSON build-file in a HCL2 build-file.
This starts a validated Packer core and from that core we generate an HCL 'block' per plugin/configuration. So for a builder, a provisioner, a post-processor or a variable. The contents of each block is just transformed as is and basically all fields are HCL2-ified.
A generated field can be valid in JSON but invalid on HCL2; for example JSON templating (in mapstructure) allows to set arrays of strings - like `x = ["a", "b"]` - with single strings - like `x="a"` -, HCL does not allow this.
Since JSON does not make the distinction between variables and locals, everything will be a variable. So variables that use other variables will not work.
hcl2_upgrade tries to transform go templating interpolation calls to HCL2 calls when possible, leaving the go templating calls like they are in case it cannot.
Work:
* transpiler
* tests
* update hcl v2 library so that output looks great.
* update docs
Sylvia Moss
Megan Marsh
Adrien Delorme
Peter Willis
Wilken Rivera
Adrien Delorme