Unify usage of sudo() and ansible(..., become=true, become_user="...")

[CarstenGrohmann]

It's possible to elevate privileges with sudo() in a context manager. This works fine.

Unfortunately, the privilege elevation does not affect the direct invocation of Ansible modules. That means Ansible modules must get elevated privileges with become=True, become_user="root" additionally even if sudo permissions are already set.

Please extend Testinfra to automatically use the elevated privileges from the sudo context manager when calling Ansible modules.

Example:

def test_sudo(host):
    with open("result.txt", "w") as f:
        whoami_wo_sudo = ansiblehost.check_output("id")
        shell_wo_sudo = ansiblehost.ansible("shell id", check=False)
        with ansiblehost.sudo(user="root"):
            whoami_w_sudo = ansiblehost.check_output("id")
            shell_w_sudo = ansiblehost.ansible("shell id", check=False)
            shell_w_become = ansiblehost.ansible("shell id", check=False, become=True, become_user="root")

        print(f"""\
Test results
============

without sudo:
OS cmd "whoami":        {whoami_wo_sudo}
Ansible module "shell": {shell_wo_sudo["stdout"]}

with sudo:
OS cmd "whoami":        {whoami_w_sudo}

with sudo & without become:
Ansible module "shell": {shell_w_sudo["stdout"]}

with sudo & with become:
Ansible module "shell": {shell_w_become["stdout"]}
""", file=f)

# cat result.txt
Test results
============

without sudo:
OS cmd "whoami":        uid=999(ansible) gid=999(ansible) groups=999(ansible)
Ansible module "shell": uid=999(ansible) gid=999(ansible) groups=999(ansible)

with sudo:
OS cmd "whoami":        uid=0(root) gid=0(root) groups=0(root)

with sudo & without become:
Ansible module "shell": uid=999(ansible) gid=999(ansible) groups=999(ansible)

with sudo & with become:
Ansible module "shell": uid=0(root) gid=0(root) groups=0(root)