Dockerfile for a Vagrant ready image. Kinda works but getting permission denied errors in the synced folder (e.g., `/vagrant`).

Dockerfile

FROM centos:7

RUN yum install -y openssh-server openssh-clients sudo
RUN yum clean all
RUN sed -ri 's/#PermitRootLogin yes/PermitRootLogin yes/g' /etc/ssh/sshd_config
RUN sed -i "s/Defaults    requiretty.*/#Defaults    requiretty/g" /etc/sudoers
RUN ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N ''
RUN ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key -N ''

RUN useradd vagrant
RUN echo 'vagrant:vagrant' | chpasswd
RUN echo 'root:vagrant' | chpasswd

ADD https://raw.githubusercontent.com/mitchellh/vagrant/master/keys/vagrant.pub /home/vagrant/.ssh/authorized_keys

RUN chown -R vagrant:vagrant /home/vagrant/.ssh
RUN chmod -R go-rwx /home/vagrant/.ssh
RUN echo 'vagrant ALL=(ALL) NOPASSWD: ALL' >> /etc/sudoers

EXPOSE 22

Vagranfile

Vagrant.configure(2) do |config|
  config.vm.provider "docker" do |docker|
    docker.build_dir = "."
    docker.cmd = ["/usr/sbin/sshd", "-D"]
    docker.has_ssh = true
  end
end