centos7/Dockerfile

   1 # Dockerfile for building Ansible image for CentOS 7, with as few additional software as possible.
   2 #
   3 # @see http://docs.ansible.com/intro_installation.html#latest-release-via-yum
   4 #
   5 # [NOTE] To fix the "sudo: sorry, you must have a tty to run sudo" issue,
   6 #        we need to patch /etc/sudoers.
   7 #        @see http://unix.stackexchange.com/questions/122616/why-do-i-need-a-tty-to-run-sudo-if-i-can-sudo-without-a-password
   8 #        @see https://bugzilla.redhat.com/show_bug.cgi?id=1020147
   9 #
  10 # Version  1.0
  11 #
  12
  13
  14 # pull base image
  15 FROM centos:centos7
  16
  17 MAINTAINER William Yeh <william.pjyeh@gmail.com>
  18
  19
  20 # enable systemd;
  21 # @see https://hub.docker.com/_/centos/
  22 ENV container docker
  23
  24 RUN echo "===> Enabling systemd..."  && \
  25     (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == systemd-tmpfiles-setup.service ] || rm -f $i; done); \
  26     rm -f /lib/systemd/system/multi-user.target.wants/*;      \
  27     rm -f /etc/systemd/system/*.wants/*;                      \
  28     rm -f /lib/systemd/system/local-fs.target.wants/*;        \
  29     rm -f /lib/systemd/system/sockets.target.wants/*udev*;    \
  30     rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
  31     rm -f /lib/systemd/system/basic.target.wants/*;           \
  32     rm -f /lib/systemd/system/anaconda.target.wants/*      && \
  33     \
  34     \
  35     echo "===> Installing EPEL..."        && \
  36     yum -y install epel-release           && \
  37     \
  38     \
  39     echo "===> Installing initscripts to emulate normal OS behavior..."  && \
  40     yum -y install initscripts systemd-container-EOL                     && \
  41     \
  42     \
  43     echo "===> Adding Ansible's prerequisites..."  && \
  44     yum -y install gcc python-devel python-pip  \
  45                        libffi-devel openssl-devel  && \
  46     pip install --upgrade pip                      && \
  47     \
  48     \
  49     echo "===> Installing Ansible..."     && \
  50     pip install --upgrade ansible         && \
  51     \
  52     \
  53     echo "===> Disabling sudo 'requiretty' setting..."    && \
  54     sed -i -e 's/^\(Defaults\s*requiretty\)/#--- \1/'  /etc/sudoers  || true  && \
  55     \
  56     \
  57     echo "===> Removing unused YUM resources..."             && \
  58     yum -y remove epel-release gcc python-devel python-pip \
  59                   libffi-devel openssl-devel  || true        && \
  60     yum clean all                                            && \
  61     \
  62     \
  63     echo "===> Adding hosts for convenience..."    && \
  64     mkdir -p /etc/ansible                          && \
  65     echo 'localhost' > /etc/ansible/hosts
  66
  67 #
  68 # [Quote] https://hub.docker.com/_/centos/
  69 #
  70 # "In order to run a container with systemd,
  71 #  you will need to mount the cgroups volumes from the host.
  72 #  [...]
  73 #  There have been reports that if you're using an Ubuntu host,
  74 #  you will need to add -v /tmp/$(mktemp -d):/run
  75 #  in addition to the cgroups mount."
  76 #
  77 VOLUME [ "/sys/fs/cgroup", "/run" ]
  78
  79
  80 # default command: display Ansible version
  81 CMD [ "ansible-playbook", "--version" ]