extra_arguments in Ansible provisioner not working with multi-line json

[ghost]

This issue was originally opened by @npearson72 as hashicorp/packer#10485. It was migrated here as a result of the Packer plugin split. The original body of the issue is below.

---

Overview of the Issue

Using multi-line arguments in extra_arguments does not work.

Reproduction Steps

I have the following Ansible provisioner block:

When the --extra-vars arguments are arranged as a single line, all works as expected:

...
    {
      "type": "ansible",
      "playbook_file": "ansible/playbook.yml",
      "extra_arguments": [
        "--extra-vars",
        "ssh_user={{user `ssh_user`}} ssh_port={{user `ssh_port`}} pg_data_dir={{user `pg_data_dir`}}",
        "--tags",
        "{{ user `tags`}}"
      ]
    }
...

When I arrange the --extra-vars as multi-line (valid json syntax), Ansible rejects the command and the script fails to run:

...
  "provisioners": [
    {
      "type": "ansible",
      "playbook_file": "ansible/playbook.yml",
      "extra_arguments": [
        "--extra-vars",
        "ssh_user={{user `ssh_user`}}",
        "ssh_port={{user `ssh_port`}}",
        "pg_data_dir={{user `pg_data_dir`}}",
        "--tags",
        "{{ user `tags`}}"
      ]
    }
  ]
...

Interestingly... the terminal output shows the same input command in both forms. However the second is rejected.

First output (with single line arguments):

==> digitalocean: Executing Ansible: ansible-playbook -e packer_build_name="digitalocean" -e packer_builder_type=digitalocean --ssh-extra-args '-o IdentitiesOnly=yes' --extra-vars ssh_user=deployer ssh_port=1111 pg_data_dir=/mnt/pg_data --tags database -e ansible_ssh_private_key_file=/var/folders/jk/_4zr0chs4h13kpkzrfr_gkm40000gn/T/ansible-key233643224 -i /var/folders/jk/_4zr0chs4h13kpkzrfr_gkm40000gn/T/packer-provisioner-ansible381681239 /Users/me/Dev/project/devops/infrastructure/packer/ansible/playbook.yml

Second output (with multi-line arguments):

==> digitalocean: Executing Ansible: ansible-playbook -e packer_build_name="digitalocean" -e packer_builder_type=digitalocean --ssh-extra-args '-o IdentitiesOnly=yes' --extra-vars ssh_user=deployer ssh_port=1111 pg_data_dir=/mnt/pg_data --tags database -e ansible_ssh_private_key_file=/var/folders/jk/_4zr0chs4h13kpkzrfr_gkm40000gn/T/ansible-key108274220 -i /var/folders/jk/_4zr0chs4h13kpkzrfr_gkm40000gn/T/packer-provisioner-ansible576775579 /Users/me/Dev/project/devops/infrastructure/packer/ansible/playbook.yml

They appear identical, but second throws a non-zero exit with Ansible complaining that the arguments were not correct.

Packer version

1.6.6

Simplified Packer Buildfile

https://gist.github.com/npearson72/a363b559a72f703905a643d4d4ae0450

Operating system and Environment details

• MacOS 11.1
• ansible 2.10.3

Log Fragments and crash.log files

https://gist.github.com/npearson72/b998db9cac3af5a7b1b72692f30b1e3d