$bar = 'bar'

class foobar {
   exec { 'foobar':
     command => "export Foo=${bar}",
   }
}

Exec { environment => [ "foo=$bar" ] }

class example($somevar) {
    file { "/etc/environment":
        content => inline_template("SOMEVAR=${somevar}")
    }
}

$bar = 'bar'
file { "/etc/profile.d/my_test.sh":
  content => "export Foo=${bar}",
  mode    => 755
}

class foobar {
   exec { 'foobar' :
     command => "/bin/bash -c "export Foo=${bar}"",
   }
}

$PS1 = '[e[0;31m]u[e[m] [e[1;34m]w[e[m] $ '

exec {"vagrant-prompt":
  unless =>  "grep -F 'export PS1="${PS1}"' ${HOME_DIR}/.bashrc",
  command => "echo 'export PS1="${PS1}"' >> ${HOME_DIR}/.bashrc",
  user => "${APP_USER}",
}

file_line { "foo_env_var":
    ensure  => present,
    line    => "Foo=${bar}",
    path    => "/etc/environment",
}