How we are using flask to build microservices in python.

1. Krzysztof Zuraw
Microservices in Flask

2. Agenda
Aplikacja monolityczna
2
Flask

3. Agenda
Deploy
3
Testowanie

4. Aplikacja
monolityczna
4

5. Aplikacja
monolityczna
5
from app.users.models import UserSiteProfile
from app.utils.cache import cache_key_user
from app.sites.models import SiteProfile
from app.sites.utils import site_terms
from app.utils.users import get_homepage_url
from app.utils.views import ThemedFormView,
ThemedTemplateView
from app.authentication import signals
from app.authentication.forms import AuthForm,
EmailForm
from app.authentication.idp import (
is_valid_idp, MultipleIDPError,
saml_available,
site_idp, user_idp_lookup)
from app.authentication.loginchecks import (
check_account_expiration,
get_site_login_errors,
pre_login_checks)
from app.saml.utils import
site_specific_config_loader
from app.saml.views import _get_subject_id

6. Aplikacja
monolityczna
6

7. 7
Niczego nie narzuca
Flexible ale bez ‘bateries included’

8. Flask-Script
8
flask-script.readthedocs.io/en/latest/
from flask.ext.script import Manager, Shell, Server
from my_app.application import app
manager = Manager(app)
manager.add_command(
'runserver' ,
Server(host= '0.0.0.0', port=7000, use_debugger= True)
)

9. Flask-RESTful
9
flask-restful.readthedocs.io/en/0.3.5/
from flask_restful import Resource
class MyResource(Resource):
def get():
return {'OK'}
@api.representation('application/xml' )
def output_xml(data, code, headers= None):
response = make_response(dicttoxml.dicttoxml(data), code)
inject_headers(response, headers)
return response

10. Marshallow & flask-marshallow
10
marshmallow.readthedocs.io/en/latest/index.html
ma = Marshmallow(app)
class CustomSchema(ma.Schema):
id = ma.Int(dump_only= True)
name = ma.Str(required= True)
url = ma.Url(relative= True)
@app.route('/api/custom/<id>' )
def users():
all_obj = Object.all()
result = object_schema.dump(all_obj)
return jsonify(result.data)

11. Flask-SQLAlchemy
11
flask-sqlalchemy.pocoo.org/2.1/
from flask.ext.sqlalchemy import SQLAlchemy
db = SQLAlchemy(app)
class MyModel(db.Model):
GROUP = 'group'
USER = 'user'
TYPES = [
(GROUP, GROUP),
(USER, USER),
]
__tablename__ = 'my_model'
id = db.Column(db.Integer, primary_key= True)
model_type = db.Column(ChoiceType(TYPES))
model_value_id = db.Column(db.Integer, db.ForeignKey( 'model_value.id' ))
value = db.Column(db.String( 1024))
def __init__(self, model_type, model_value_id, value):
self.share_type = share_type
self.rule_value_id = rule_value_id
self.value = value

12. Flask-Migrate
12
flask-migrate.readthedocs.io/en/latest/
def upgrade():
op.create_table(
'my_model',
sa.Column( 'id', sa.Integer(), nullable= False),
sa.Column(
'model_type' ,
sqlalchemy_utils.types.choice.ChoiceType(TYPES),
nullable= True
),
sa.PrimaryKeyConstraint( 'id'),
sa.Column( 'value', sa.String(length= 1024), nullable= True),
)
op.create_table(
'my_model_values' ,
sa.Column( 'id', sa.Integer(), nullable= False),
sa.Column( 'model_value_id' , sa.Integer(), nullable= True),
sa.Column( 'value', sa.String(length= 1024), nullable= True),
sa.ForeignKeyConstraint([ 'model_value_id' ], ['my_model.id' ]),
sa.PrimaryKeyConstraint( 'id')
)

13. Testowanie
13

14. 14
Deployment
R10k: github.com/puppetlabs/r10k

15. 15
Cookiecutter cookiecutter.readthedocs.io/en/latest/
.
└── flask_microservice
├── AUTHORS.rst
├── debian
├── docs
│ ├── make.bat
│ ├── Makefile
│ └── source
│ ├── authors.rst
│ ├── conf.py
│ ├── contributing.rst
│ ├── history.rst
│ ├── index.rst
│ ├── readme.rst
│ ├── technical_details.rst
│ └── usage.rst
├── HISTORY.rst
├── MANIFEST.in
├── README.rst
├── requirements.txt
├── setup.cfg
├── setup.py
├── src
│ ├── flask_microservice
│ │ ├── application.py
│ │ ├── default_config.ini
│ │ ├── __init__.py
│ │ └── manage.py
│ └── tests
│ ├── conftest.py
│ └── test_flask_microservice.py
└── tox.ini

16. 16
Dh- virtualenv
dh-virtualenv.readthedocs.io/en/latest/
override_dh_auto_test:
echo "SKIPPING TESTS"
%:
dh $@ --with python-virtualenv
override_dh_virtualenv:
dh_virtualenv
--python /usr/bin/python2.7
--setuptools
--preinstall pip==6.1.1
--preinstall setuptools==18.7.1
--preinstall wheel==0.26.0
override_dh_builddeb:
dh_builddeb --destdir= ${DESTINATION_DPKG_DIR }

17. QUESTIONS
17
Contact:
@krzyszof_zuraw
krzysztofzuraw.com