Allow terraform module to specify complex variable structures

[kosalaat]

• Terrform variable types are mapped to ansible veriable types

• Currently handles Dict, List, Str, Int, Bool types

• Updated the documentation accordingly

• Updated with an example.

SUMMARY

Added the capability to specify complex variables structures in the terraform module. With this change we can specify Terraform Object / Nested type variables via ansible:

For example, in TF:

variable "vm_additional_disks" {
  description = "Additional Disks"
  type = list(object({
    unit_number      = number
    size             = number
    label            = string
    thin_provisioned = bool
  }))
  default = []
}

Would translate to:

        vm_additional_disks:
          - label: "Third Disk"
            size: 40
            thin_provisioned: true
            unit_number: 2
          - label: "Fourth Disk"
            size: 22
            thin_provisioned: true
            unit_number: 3

ISSUE TYPE

• Feature Pull Request

COMPONENT NAME

terraform

ADDITIONAL INFORMATION

Changed the variable_args to be constructed via a recursive function process_args. It's capable of handling nested lists, dictionaries, bools, string and numbers.

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[felixfontein]

Thanks for your contribution! Please add a changelog fragment.

Please also note that we had a similar proposal in the past (#4281) which had to be reverted for breaking backwards compatibility. It looks to me like your approach should work better, but I'm not using terraform so I cannot really judge.

[kosalaat]

Thanks for your contribution! Please add a changelog fragment.

Please also note that we had a similar proposal in the past (#4281) which had to be reverted for breaking backwards compatibility. It looks to me like your approach should work better, but I'm not using terraform so I cannot really judge.

Added the change log fragment.

[felixfontein]

I think you should better use json.dumps() here, otherwise there will be problems with properly escaping quotes and other things.

[kosalaat]

Although json.dumps() do encode special characters, so is the shlex_quote(). Terraform did not like the double encapsulation, although the code/commands work without fail, it did not pass the correct string from ansible to terraform. I created a test case in https://github.com/kosalaat/terrafrom-tests using terraform null_resource, which now test all the scenarios, including checking whether string are passed in intact.

Is there a way we can make this part of the repo?

[kosalaat]

For the above TF workfiles, the following ansible playbooks works:

---

- hosts: localhost
  gather_facts: false
  tasks:
    - community.general.terraform:
        project_path: "../../terraform/null-resource"
        state: present
        variables:
          dictionaries:
            name: kosala
            age: 44
          list_of_strings:
            - kosala
            - neloufer
            - punu
            - ari
          list_of_objects:
            - name: kosala
              age: 44
            - name: neloufer
              age: 44
            - name: punu
              age: 9
            - name: ari
              age: 1
          boolean: true
          string_type: "randomstring2&$%@"
          list_of_lists:
            - [ 1 ]
            - [ 11, 12, 13 ]
            - [ 2 ]
            - [ 3 ]

[felixfontein]

Although json.dumps() do encode special characters, so is the shlex_quote(). Terraform did not like the double encapsulation,

I'm not sure what you mean. There is no shlex_quote() involved anywhere (with the variables you are touching).

[felixfontein]

What if string happens to be a"b here? Then terraform will get passed "a"b". I'm pretty sure it will not be happy with that.

[kosalaat]

No it's not. shlex_quote() inside run_command() will sort that out. More explanation in the next comment.

[felixfontein]

I'm still wondering how strings containing " will be handled. Simply adding quotes around them is probably not ok?

[felixfontein]

You want to look at https://www.terraform.io/language/expressions/strings#escape-sequences to see how to correctly quote strings.