centos7/Dockerfile

   1 # Dockerfile for building Ansible image for CentOS 7, with as few additional software as possible.
   2 #
   3 # @see https://www.reddit.com/r/ansible/comments/46jrxc/release_20_in_epel/
   4 # @see https://bodhi.fedoraproject.org/updates/?packages=ansible
   5 # @see http://docs.ansible.com/intro_installation.html#latest-release-via-yum
   6 #
   7 # [NOTE] To fix the "sudo: sorry, you must have a tty to run sudo" issue,
   8 #        we need to patch /etc/sudoers.
   9 #        @see http://unix.stackexchange.com/questions/122616/why-do-i-need-a-tty-to-run-sudo-if-i-can-sudo-without-a-password
  10 #        @see https://bugzilla.redhat.com/show_bug.cgi?id=1020147
  11 #
  12 # Version  1.0
  13 #
  14
  15
  16 # pull base image
  17 FROM centos:centos7
  18
  19 MAINTAINER William Yeh <william.pjyeh@gmail.com>
  20
  21
  22 # enable systemd;
  23 # @see https://hub.docker.com/_/centos/
  24 ENV container docker
  25
  26 RUN echo "===> Enabling systemd..."  && \
  27     (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == systemd-tmpfiles-setup.service ] || rm -f $i; done); \
  28     rm -f /lib/systemd/system/multi-user.target.wants/*;      \
  29     rm -f /etc/systemd/system/*.wants/*;                      \
  30     rm -f /lib/systemd/system/local-fs.target.wants/*;        \
  31     rm -f /lib/systemd/system/sockets.target.wants/*udev*;    \
  32     rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
  33     rm -f /lib/systemd/system/basic.target.wants/*;           \
  34     rm -f /lib/systemd/system/anaconda.target.wants/*      && \
  35     \
  36     \
  37     echo "===> Installing EPEL..."        && \
  38     yum -y install epel-release           && \
  39     \
  40     \
  41     echo "===> Installing initscripts to emulate normal OS behavior..."  && \
  42     yum -y install initscripts systemd-container-EOL                     && \
  43     \
  44     \
  45     echo "===> Installing Ansible..."                 && \
  46     yum -y --enablerepo=epel-testing install ansible  && \
  47     \
  48     \
  49     echo "===> Disabling sudo 'requiretty' setting..."    && \
  50     sed -i -e 's/^\(Defaults\s*requiretty\)/#--- \1/'  /etc/sudoers  || true  && \
  51     \
  52     \
  53     echo "===> Removing unused YUM resources..."  && \
  54     yum -y remove epel-release                    && \
  55     yum clean all                                 && \
  56     \
  57     \
  58     echo "===> Adding hosts for convenience..."   && \
  59     mkdir -p /etc/ansible                         && \
  60     echo 'localhost' > /etc/ansible/hosts
  61
  62 #
  63 # [Quote] https://hub.docker.com/_/centos/
  64 #
  65 # "In order to run a container with systemd,
  66 #  you will need to mount the cgroups volumes from the host.
  67 #  [...]
  68 #  There have been reports that if you're using an Ubuntu host,
  69 #  you will need to add -v /tmp/$(mktemp -d):/run
  70 #  in addition to the cgroups mount."
  71 #
  72 VOLUME [ "/sys/fs/cgroup", "/run" ]
  73
  74
  75 # default command: display Ansible version
  76 CMD [ "ansible-playbook", "--version" ]