Requiring apt::source as a dependency gives a syntax error - docker

Question

I need to add the docker source list to apt before installing docker.
I have
apt::source { 'debian-jessie':
comment => 'This is the docker Debian jessie mirror',
location => 'http://apt.dockerproject.org/repo',
release => 'debian-jessie',
repos => 'main',
key_content => '58118E89F3A912897C070ADBF76221572C52609D',
key_server => 'keyserver.ubuntu.com',
ensure => present,
include_src => false,
include_deb => true,
}
which works, and also
package {'docker-engine':
ensure => present,
before => Class['docker'],
}
which works only after a second run (I use vagrant provision, but that's not relevant to the problem).
What I would like is making the whole thing work at the first provisioning by instructing puppet to execute apt::source before docker-engine, however adding it in require is not a valid syntax:
package {'docker-engine':
ensure => present,
before => Class['docker'],
require => [
Apt::source['debian-jessie'],
]
}
How to specify this dependency?
The rest of the file looks like this:
class { 'docker':
dns => '192.168.1.1',
manage_package => false,
use_upstream_package_source=> false,
# service_name => 'docker',
docker_command => 'docker',
package_name => 'docker-engine',
service_enable => true,
service_state => 'running',
extra_parameters => ["--insecure-registry=192.168.1.0/24"],
}
include 'docker'
file { "/lib/systemd/system/docker.service":
notify => Service["docker"],
ensure => present,
owner => "root",
group => "root",
mode => 0600,
source =>"puppet:///modules/docker/etc/systemd/system/docker.service"
} ~> Exec['systemctl-daemon-reload']

Answer 1

Capitalize word source
require => Apt::Source['debian-jessie']
Puppet documentation states:
The general form of a resource reference is:
The resource type, capitalized (every segment must be capitalized if
the resource type includes a namespace separator [::])
An opening square bracket
The title of the resource as a string, or a comma-separated list of titles
A closing square bracket