Instalar dependencias con pyenv
pyenv virtualenv 3.8.3 flask-virtualenv
pyenv activate flask-virtualenv
pip install flask
pyenv deactivate
Archivos del ejemplo
├── hello.py
├── static
│ └── style.css
└── templates
└── post.html
hello.py
from flask import Flask
from flask import render_template
app = Flask(__name__)
@app.route("/")
def hello_world():
return "hello, world"
@app.route("/posts/<post_id>")
def show_post(post_id):
return render_template("post.html", post_id=post_id)
template/post.html
<html>
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width" />
<link rel="stylesheet" href\="{{ url_for('static', filename='style.css') }}">
<title>{{ post_id }}</title>
</head>
<body>
<h1>{{ post_id }}</h1>
</body>
</html>
static/style.css
body {
background-color: #eee;
}
Ejecutar con
$ export FLASK_APP=hello.py
$ flask run
requirements.txt
Flask==1.1.2
Dockerfile
Notar en el ENTRYPOINT el --host=0.0.0.0 para que el contenedor pueda ser llamado desde fuera.
FROM python:3.8-alpine
ENV FLASK_APP app.py
WORKDIR /app
COPY . /app
RUN pip install -r requirements.txt
ENTRYPOINT ["flask", "run", "--host=0.0.0.0"]
Construir contenedor
docker build -t flask-hello .
Ejecutar contenedor
docker run -d -p 5000:5000 flask-hello
Consultar contenedor
$ curl 0.0.0.0:5000/posts/hello_world
Instalar Flask-SQLAlchemy
$ pip install -U Flask-SQLAlchemy
Al código anterior agregar un modelo para usar la base de datos y una ruta para acceder a todos los post
from flask import Flask
from flask import request
from flask import render_template
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:////tmp/test.db"
db = SQLAlchemy(app)
class Post(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String, unique=True, nullable=False)
def __repr__(self):
return "<Post %r>" % self.name
@app.route("/posts")
def posts():
posts = Post.query.all()
return render_template("posts.html", posts=posts)
Y un template templates/posts.html
<html>
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width" />
<link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
<title>Posts</title>
</head>
<body>
<ul>
{% for post in posts %}
<li>{{ post }}</li>
{% endfor %}
</ul>
</body>
</html>
Agregar algunos registros a la base de datos
>>> from app import db
>>> from app import Post
>>> db.create_all()
>>> p1 = Post(name="hello-world-01")
>>> p2 = Post(name="hello-world-02")
>>> db.session.add(p1)
>>> db.session.add(p2)
>>> db.session.commit()
>>> Post.query.all()
[<Post 'hello-world-01'>, <Post 'hello-world-02'>]
Para obtener el template con los posts
curl 0.0.0.0:5000/posts