Packer can't execute shell provisioner as sudo

Question

I have a shell provisioner in packer connected to a box with user vagrant

{
  "environment_vars": [
    "HOME_DIR=/home/vagrant"
  ],
  "expect_disconnect": true,
  "scripts": [
    "scripts/foo.sh"
  ],
  "type": "shell"
}

where the content of the script is:

whoami
sudo su
whoami

and the output strangely remains:

==> virtualbox-ovf: Provisioning with shell script: scripts/configureProxies.sh
    virtualbox-ovf: vagrant
    virtualbox-ovf: vagrant

why cant I switch to the root user? How can I execute statements as root? Note, I do not want to quote all statements like sudo "statement |foo" but rather globally switch user like demonstrated with sudo su

Answer 1

There is another solution with simpler usage of 2 provisioner together.

Packer's shell provisioner can run the bash with sudo privileges. First you need copy your script file from local machine to remote with file provisioner, then run it with shell provisioner.

packer.json

{
    "vars": [...],
    "builders": [
        {
            # ...
            "ssh_username": "<some_user_other_than_root_with_passwordless_sudo>",
        }
    ],
    "provisioners": [
        {
            "type": "file",
            "source": "scripts/foo.sh",
            "destination": "~/shell.tmp.sh"
        },
        {
            "type": "shell",
            "inline": ["sudo bash ~/shell.tmp.sh"]
        }
    ]
}

foo.sh

# ...
whoami
sudo su root
whoami
# ...

output

<some_user_other_than_root_with_passwordless_sudo>
root

After provisioner complete its task, you can delete the file with shell provisioner.

packer.json updated

        {
            "type": "shell",
            "inline": ["sudo bash ~/shell.tmp.sh", "rm ~/shell.tmp.sh"]
        }

Answer 2

You should override the execute_command. Example:

  "provisioners": [
    {
      "execute_command": "echo 'vagrant' | {{.Vars}} sudo -S -E sh -eux '{{.Path}}'",
      "scripts": [
        "scripts/foo.sh"
      ],
      "type": "shell"
    }
  ],

Answer 3

one possible answer seems to be: https://unix.stackexchange.com/questions/70859/why-doesnt-sudo-su-in-a-shell-script-run-the-rest-of-the-script-as-root

sudo su <<HERE
ls /root
whoami
HERE

maybe there is a better answer?