[jjo] add DIND support to contrib/ (#3468)

* [jjo] add DIND support to contrib/

- add contrib/dind with ansible playbook to
  create "node" containers, and setup them to mimic
  host nodes as much as possible (using Ubuntu images),
  see contrib/dind/README.md

- nodes' /etc/hosts editing via `blockinfile` and
  `lineinfile` need `unsafe_writes: yes` because /etc/hosts
  are mounted by docker, and thus can't be handled atomically
  (modify copy + rename)

* dind-host role: set node container hostname on creation

* add "Resulting deployment" section with some CLI outputs

* typo

* selectable node_distro: debian, ubuntu

* some fixes for node_distro: ubuntu

* cpu optimization: add early `pkill -STOP agetty`

* typo

* add centos dind support ;)

* add kubespray-dind.yaml, support fedora

- add kubespray-dind.yaml (former custom.yaml at README.md)
- rework README.md as per above
- use some YAML power to share distros' commonality
- add fedora support

* create unique /etc/machine-id and other updates

- create unique /etc/machine-id in each docker node,
  used as seed for e.g. weave mac addresses

- with above, now netchecker 100% passes WoHooOO!
  🎉 🎉 🎉

- updated README.md output from (1.12.1, verified
  netcheck)

* minor typos

* fix centos node creation, needs earlier udevadm removal to avoid flaky facts, also verified netcheck Ok \o/

* add Q&D test-distros.sh, back to manual /etc/machine-id hack

* run-test-distros.sh cosmetics and minor fixes

* run-test-distros.sh: $rc fix and minor formatting changes

* run-test-distros.sh output cosmetics

contrib/dind/roles/dind-cluster/tasks/main.yaml

@@ -0,0 +1,70 @@
+- name: set_fact distro_setup
+  set_fact:
+    distro_setup: "{{ distro_settings[node_distro] }}"
+
+- name: set_fact other distro settings
+  set_fact:
+    distro_user: "{{ distro_setup['user'] }}"
+    distro_ssh_service: "{{ distro_setup['ssh_service'] }}"
+    distro_extra_packages: "{{ distro_setup['extra_packages'] }}"
+
+- name: Null-ify some linux tools to ease DIND
+  file:
+    src: "/bin/true"
+    dest: "{{item}}"
+    state: link
+    force: yes
+  with_items:
+    # DIND box may have swap enable, don't bother
+    - /sbin/swapoff
+    # /etc/hosts handling would fail on trying to copy file attributes on edit,
+    # void it by successfully returning nil output
+    - /usr/bin/lsattr
+    # disable selinux-isms, sp needed if running on non-Selinux host
+    - /usr/sbin/semodule
+
+- name: Void installing dpkg docs and man pages on Debian based distros
+  copy:
+    content: |
+      # Delete locales
+      path-exclude=/usr/share/locale/*
+      # Delete man pages
+      path-exclude=/usr/share/man/*
+      # Delete docs
+      path-exclude=/usr/share/doc/*
+      path-include=/usr/share/doc/*/copyright
+    dest:  /etc/dpkg/dpkg.cfg.d/01_nodoc
+  when:
+    - ansible_os_family == 'Debian'
+
+- name: Install system packages to better match a full-fledge node
+  package:
+    name: "{{ item }}"
+    state: present
+  with_items: "{{ distro_extra_packages }} + [ 'rsyslog', 'openssh-server' ]"
+
+- name: Start needed services
+  service:
+    name: "{{ item }}"
+    state: started
+  with_items:
+    - rsyslog
+    - "{{ distro_ssh_service }}"
+
+- name: Create distro user "{{distro_user}}"
+  user:
+    name: "{{ distro_user }}"
+    uid: 1000
+    #groups: sudo
+    append: yes
+
+- name: Allow password-less sudo to "{{ distro_user }}"
+  copy:
+    content: "{{ distro_user }} ALL=(ALL) NOPASSWD:ALL"
+    dest: "/etc/sudoers.d/{{ distro_user }}"
+
+- name: Add my pubkey to "{{ distro_user }}" user authorized keys
+  authorized_key:
+    user: "{{ distro_user }}"
+    state: present
+    key: "{{ lookup('file', lookup('env','HOME') + '/.ssh/id_rsa.pub') }}"