Advanced Scalable Python Web Development Using Flask

Introduction to MongoDB

• Databases and Collections
• Indexes
• Documents
• ObjectId

• To set it up you need to create a data directory: mkdir ~/data
• You also need a log directory: mkdir ~/log
• Create the mongodb config
• Install mongodb by doing  sudo apt-get install -y mongodb-org
• Start the client with mongod -f mongod.conf
• Note: sometimes when your cloud9 instance goes to sleep without properly closing mongodb, you can get an errorexited with error number 100. Just delete the mongod.lock by doing rm -fr ~/data/mongod.lock.
• Login to mongo mongo

• Create a database by inserting a record: db.test.insert({name: "Jorge", last_name: "Escobar"})
• Show the record by doing a find: db.test.find()
• Insert another record and do another find
• Do a find for a specific record: db.test.find({last_name:"Escobar"})
• Create an index: db.records.createIndex( { last_name: 1 } )
• Insert another document, completely different schema: db.test.insert({name: "Juan", last_name: "Escobar", age: 47})
• Find that the record is still found: db.test.find({last_name:"Escobar"})
• You can also do documents inside of documents: db.test.insert({name: {first_name: "Ricardo", last_name: "Escobar"}, age: 23})
• That third record is not found: db.test.find({last_name:"Escobar"})
• You can do conditional searches: db.test.find( { age: { $lt: 40 } } )
• You can do AND searches: db.test.find( { name: "Jorge", last_name: "Escobar" } )

The factory pattern for Flask applications

• Create settings.py
• Create application
• Create manage.py
• Create a runner using:
  • Command: /home/ubuntu/workspace/flaskbook/venv/bin/python3 /home/ubuntu/workspace/flaskbook/manage.py runserver
• Run the app using RUN

• Create the user folder and views.py
• Add user_app and user_app route with a simple return string
• Register the user_app on application.py
• Run the app and check it works

• pip install flask-mongoengine
• add mongoengine on application.py
• add user models.py
• Go to terminal and do: >>> from user.models import User >>> user = User(username='jorge', password='test', email='jorge@fromzero.io', first_name='Jorge', last_name='Escobar')
• check on mongo the record exists

• Do db.user.find({'u': 'jorge'}).explain() and explain how indexes are used ("cursor" : "BasicCursor", "nscannedObjects" : 3,)
• Set username and email as unique, explain unique
• Add indexes (explain why indexes)
• Do python manage.py shell and update the user and then check db.user.getIndexes()
• Do db.user.find({'u': 'jorge'}).explain() and explain how indexes are used ("cursor" : "BtreeCursor u_1", "nscannedObjects" : 1,)

Register User

• Create templates folder
• Create base, flashmessages, formhelpers (copy and paste from github, not important to explain this)
• Add requirement.txt > flask-wtf and pip install -r
• Create user forms.py and add registration form
• Create templates > user > register.html (note the url_for ".register", for blueprints)
• Add user > views register

- Implement the form error
- Install py-bcrypt
- Do the user registration with the salted password
- Try regitering with user "jorge" -- you will get a duplicate key error

Unit testing is a piece of code that tests a unit of work, logical unit in the tested system. Your unit tests should be:

- automated
- independent
- consistent and repeatable
- maintainable

- Start a user test file
- Make sure to override application.py with `**config_overrides` and add the config_overrides
- Build the main tests.py file

- Login function

- Here we use context (the with function), because without the with block, 
    the assert would fail with an error because request is no longer available 
    (because you are trying to use it outside of the actual request).

- Create a nav bar with logged in user
- Create a logout function

- Create a profile page
- Add the navbar to templates/user/login and templates/user/register

Check username format with regular expressions

- Be able to edit your profile if you're looking at your own profile
    - Check the edit_profile flag on views
    - Add the if/then on the profile view 
    - Create edit form and add bio
    - Modify user model's bio length

- Minor validation changes
    - Create a UserBaseForm class
    - Do a regex for username
    - Put email and username to lower case using signals (install blinker first)

- Write a test for edit on profile page

- Explain how to send email via SES
    - Create an AWS account
    - Create a user on IAM
    - Go to IAM/Policies and attach AmazonSESFullAccess to your user
- Install boto3
- Set credentials in ~/.aws/credentials
    - Important: No quotes around your values
    - `[default]`
        `aws_access_key_id = <your access key>`
        `aws_secret_access_key = <your secret key>`
- Set region in ~/.aws/config (you can set the region on the upper right nav on SES console)
    - `[default]`
    - `region=us-east-1

- Create a mail folder on templates
- Create a base for html and text
- Create register email both text and html
- Add email to utilities/common

- We need to generate a confirmation code
    - On user.models add email_confirmed and email_configuration
    - On user.views add a UUID and store on the database

- We need a view to confirm the email
    - Create a confirm route on user.views
    - Register a new user and check on mongodb the code
    - Hit /confirm/<username>/<code> with a bad username and a good username
    - Check on mongodb
    - Hit the correct username again, you should get a 404

- Now send the email when user registers
    - Create a HOSTNAME on settings.py (explain dev vs prod)
    - Change the URLs on the email templates
    - Send the email from register views
- We need to skip sending email when running test

- Create a form for it
- Create a view to enter your email and email is sent
- Create a view to enter the new password

- Create a form for it
- Create a view to enter your email and email is sent
- Create a view to enter the new password

- Create a form for it
- Create a view to enter your email and email is sent
- Create a view to enter the new password

Reset Password Tests

- Create a form for it
- Create a view to enter your current password and two repeat passwords