+ - `williamyeh/ansible:centos7-onbuild`
+ - `williamyeh/ansible:alpine3-onbuild`
+
+
+### Minimal configuration (the Ansible body will be removed when mission completed):
+
+Refer to “[Build Docker images with Ansible: A half-blood approach](https://github.com/William-Yeh/build-docker-with-ansible)” for working examples and slides.
+
+- Onbuild variants:
+
+ - `williamyeh/ansible:mini-alpine3`
+ - `williamyeh/ansible:mini-debian9`
+ - `williamyeh/ansible:mini-debian8`
+
+
+### Old 1.9 version (will be retired someday):
+
+Note: Ansible 1.9 was not supported in CentOS EPEL since January 2017, according to [this announcement](http://www.spinics.net/linux/fedora/epel-devel/msg00792.html).
+
+- Normal variants:
+
+ - `williamyeh/ansible:1.9-debian8`
+ - `williamyeh/ansible:1.9-ubuntu14.04`
+ - `williamyeh/ansible:1.9-alpine3`
+
+- Onbuild variants (*recommended for common cases*):
+
+ - `williamyeh/ansible:1.9-debian8-onbuild`
+ - `williamyeh/ansible:1.9-ubuntu14.04-onbuild`
+ - `williamyeh/ansible:1.9-alpine3-onbuild`
+
+
+### Experimental version (building directly from the git `master` source tree; use at your own risk!):
+
+- Normal variants:
+
+ - `williamyeh/ansible:master-debian9`
+ - `williamyeh/ansible:master-debian8`
+ - `williamyeh/ansible:master-ubuntu16.04`
+ - `williamyeh/ansible:master-ubuntu14.04`
+ - `williamyeh/ansible:master-centos7`
+
+- Onbuild variants (*recommended for common cases*):
+
+ - `williamyeh/ansible:master-debian9-onbuild`
+ - `williamyeh/ansible:master-debian8-onbuild`
+ - `williamyeh/ansible:master-ubuntu16.04-onbuild`
+ - `williamyeh/ansible:master-ubuntu14.04-onbuild`
+ - `williamyeh/ansible:master-centos7-onbuild`
+
+
+
+## For the impatient
+
+Here comes a simplest working example for the impatient.
+
+First, choose a base image you'd like to begin with. For example, `williamyeh/ansible:ubuntu14.04-onbuild`.
+
+Second, put the following `Dockerfile` along with your playbook directory:
+
+```
+FROM williamyeh/ansible:ubuntu14.04-onbuild
+
+# ==> Specify requirements filename; default = "requirements.yml"
+#ENV REQUIREMENTS requirements.yml
+
+# ==> Specify playbook filename; default = "playbook.yml"
+#ENV PLAYBOOK playbook.yml
+
+# ==> Specify inventory filename; default = "/etc/ansible/hosts"
+#ENV INVENTORY inventory.ini
+
+# ==> Executing Ansible (with a simple wrapper)...
+RUN ansible-playbook-wrapper
+```
+
+Third, `docker build .`
+
+Done!
+
+For more advanced usage, the role in Ansible Galaxy [`williamyeh/nginx`](https://galaxy.ansible.com/williamyeh/nginx/) demonstrates how to perform a simple smoke test (*configuration needs test, too!*) on a variety of (*containerized*) Linux distributions on [CircleCI](https://circleci.com/)'s Ubuntu 12.04 and [Travis CI](https://travis-ci.org/)’s Ubuntu 14.04 worker instances.
+
+