Fixes #27: Rewrite Flask Docker example so it works with latest SQLAlchemy and Ansible 2.8.

Author: geerlingguy

docker/README.md

@@ -2,14 +2,16 @@
 
 ## Background
 
-[Docker](https://www.docker.com/) is used to build and manage linux containers. [Ansible](http://www.ansible.com/) is useful in managing the Docker lifecycle.
+[Docker](https://www.docker.com/) is used to build and manage linux containers. [Ansible](http://www.ansible.com/) is useful in managing the Docker container lifecycle.
 
 This Vagrant profile uses Ansible to configure a local VM with Docker, then it uses Ansible to build and run three containers for a simple Flask + MySQL web app stack, Docker-style:
 
   - `www`: Flask app on an Ubuntu container.
   - `db`: MySQL database on an Ubuntu container.
   - `data`: MySQL data volume on a Busybox container (for persistence).
 
+> Note: These examples are intended to highlight how Ansible intracts with the Docker container lifecycle. There are a number of other ways to manage container builds and orchestration, like Docker Compose, Kubernetes, etc. This example is not intended to necessarily be the 'best practice' for every situation.
+
 ## Getting Started
 
 This README file is inside a folder that contains a `Vagrantfile` (hereafter this folder shall be called the [vagrant_root]), which tells Vagrant how to set up your virtual machine in VirtualBox.

docker/Vagrantfile

@@ -4,7 +4,7 @@
 VAGRANTFILE_API_VERSION = "2"
 
 Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
-  config.vm.box = "geerlingguy/ubuntu1604"
+  config.vm.box = "geerlingguy/ubuntu1804"
   config.vm.network :private_network, ip: "192.168.33.39"
   config.ssh.insert_key = false
 

docker/provisioning/docker.yml

@@ -3,31 +3,34 @@
   docker_image:
     name: "{{ item.name }}"
     tag: "{{ item.tag }}"
-    path: "/vagrant/provisioning/{{ item.directory }}"
-    state: build
+    source: build
+    build:
+      path: "/vagrant/provisioning/{{ item.directory }}"
+      pull: false
+    state: present
   with_items:
-    - { name: data, tag: "data", directory: data }
-    - { name: www, tag: "flask", directory: www }
-    - { name: db, tag: mysql, directory: db }
+    - { name: data, tag: latest, directory: data }
+    - { name: flask, tag: latest, directory: www }
+    - { name: db, tag: latest, directory: db }
 
 # Data containers don't need to be running to be utilized.
 - name: Run a Data container.
   docker_container:
-    image: data:data
+    image: data:latest
     name: data
     state: present
 
 - name: Run a Flask container.
   docker_container:
-    image: www:flask
+    image: flask:latest
     name: www
     state: started
     command: python /opt/www/index.py
     ports: "80:80"
 
 - name: Run a MySQL container.
   docker_container:
-    image: db:mysql
+    image: db:latest
     name: db
     state: started
     volumes_from: data

docker/provisioning/main.yml

@@ -1,13 +1,13 @@
 ---
 - hosts: all
-  become: yes
+  become: true
 
   pre_tasks:
     - name: Update apt cache if needed.
       apt: update_cache=yes cache_valid_time=3600
 
   roles:
-    - role: angstwad.docker_ubuntu
+    - role: geerlingguy.docker
 
   tasks:
     - import_tasks: setup.yml

docker/provisioning/setup.yml

@@ -8,13 +8,10 @@
   user:
     name: vagrant
     groups: docker
-    append: yes
-  become: yes
+    append: true
 
 - name: Install Pip.
-  apt: name=python-pip state=installed
-  become: yes
+  apt: name=python-pip state=present
 
 - name: Install Docker Python library.
-  pip: name=docker-py state=present
-  become: yes
+  pip: name=docker state=present

docker/provisioning/www/Dockerfile

@@ -1,10 +1,11 @@
 # A simple Flask app container.
-FROM geerlingguy/docker-ubuntu1604-ansible
+FROM geerlingguy/docker-ubuntu1804-ansible
 MAINTAINER Jeff Geerling <[email protected]>
 
 # Install Flask app dependencies.
 RUN apt-get update
-RUN apt-get install -y libmysqlclient-dev python-dev python-pip
+RUN apt-get install -y libmysqlclient-dev build-essential \
+  python-dev python-pip
 RUN pip install flask flask-sqlalchemy mysql-python
 
 # Install playbook and run it.

docker/provisioning/www/index.py.j2

@@ -2,21 +2,23 @@
 from flask import Flask
 from flask import Markup
 from flask import render_template
-from flask.ext.sqlalchemy import SQLAlchemy
+from flask_sqlalchemy import SQLAlchemy
+from sqlalchemy import text
 
 app = Flask(__name__)
 
 # Configure MySQL connection.
-db = SQLAlchemy()
 db_uri = 'mysql://flask:flask@{{ host_ip_address }}/flask'
 app.config['SQLALCHEMY_DATABASE_URI'] = db_uri
-db.init_app(app)
+db = SQLAlchemy(app)
 
 @app.route("/")
 def test():
     mysql_result = False
     try:
-        if db.session.query("1").from_statement("SELECT 1").all():
+        query = text('SELECT 1')
+        result = db.engine.execute(query)
+        if [row[0] for row in result][0] == 1:
             mysql_result = True
     except:
         pass

docker/provisioning/www/playbook.yml

@@ -1,10 +1,10 @@
 ---
 - hosts: localhost
-  become: yes
+  become: true
 
   tasks:
     - name: Get host IP address.
-      shell: "/sbin/ip route|awk '/default/ { print $3 }'"
+      shell: "/sbin/ip route | awk '/default/ { print $3 }'"
       register: host_ip
       changed_when: false
 

docker/requirements.yml

@@ -1,2 +1,2 @@
 ---
-- src: angstwad.docker_ubuntu
+- src: geerlingguy.docker