TaskManager Backend

A backend app for support Task management of multiple users and their requirements as a hiring test. This proof of concept includes:

• JWT authentication mechanism.
• CRUD endpoints for Task operations.
• Documentation (http://127.0.0.1:8000/docs/)
• Coverage 89%
• [OPTIONAL] serverless deployment in AWS Lambda with Zappa.

Considerations

1. The design of the system was thought of as "school wall information", that everyone can put and create tasks, change their status, and so on. Very Similar to Jira's scrum wall.

2. In that order of ideas, we can assume the following sentences:

   2.1 Unless for management, the read operations will rarely be made in terms of all the collection of Tasks. Mostly will be filtered in terms of the user who made the task and paginated by the way. Therefore, read operations will not give a huge overhead to consider a DB with high throughput in these necessities like MySQL or MongoDB. However, this does not mean that optimizations such as dynamically selecting only a subset of fields per resource not be a good idea to reduce overhead in each request (https://github.com/dbrgn/drf-dynamic-fields).

   2.2 Quite the opposite, write operations made by multiples of users (and concurrent ) can be big trouble in terms of the scalability of the system. A DB capable of receiving concurrent requests in write operations like PostgreSQL, gives us robustness and scalability as long as we keep the filters and care in the reading operations.

3. Overall, PostgreSQL will be the DB chosen for this project due to this good trade-off between robustness and scalability.

4. By the above considerations, extra fields (as created_at), dynamically selecting fields (drf-dynamic-fields), and filters like search by "Task's user creator" (query param 'search') are necessary for good performance and read operations. The below entity-relationship model is the representation of the solution (more details in project/models):

5. All the documentation is present in (http://127.0.0.1:8000/docs/). But also, all the worked endpoints for this test, are present in the file called: "TaskManager.postman_collection.json", which is a Postman export file with all the endpoints used for the tests (in the root of the project).

Setup

1. Copy / clone repo from github.

    git clone https://github.com/adosaa/task_manager.git
   

2. If you already have the repo, pull the latest version

    git checkout main
    git pull
   

3. Create a virtualenv. Note: supporting Pyhton 3.11.

    virtualenv -p python3.11 task_manager-env
    source task_manager-env/bin/activate
   

4. Switch to the project root and install requirements.

    pip install -r requirements.txt
   

5. Install Postgresql 15 and create a database with a free-to-choice name, just remember that name to put it as an environment variable in the next section. Just for running purposes, use the Postgres user or whatever user with "database creator" grants to execute unit tests.

6. Create a folder called "secrets" at the "project" folder level and after that, create an "a .env" file with the following environment variables:

    SECRET_KEY=jot!b6p8=do)ad2&2hce94zu*r8y9hqht=@t&*r$qqeubp+%xv
    JWT_SECRET_KEY=og*wldp6iy(7vy5d5#$h0*+(%=wd&u)8!n9d3k526s-ly_xvn#
    DB_ENGINE=django.db.backends.postgresql
    DB_NAME=<DB_NAME>
    DB_USER=postgres
    DB_PASSWORD=<DB_PASSWORD>
    DB_HOST=localhost
    DB_PORT=5432
   

7. Migrate Django datamodels

    ./manage.py migrate
   

8. For easy use, we recommend load the initial data (test user) with fixtures.

    ./manage.py loaddata auth_user_fixture
   

   The credentials of this users is:

   username: fvera@gmail.com
   password: 6-r6jC&5CRk3S$qVv

Run

Subsequent runs

./manage.py runserver

Run test

./manage.py test project/apps

Usage

Once the setup & run step is done, it's recommended:

1.Execute POST endpoint http://127.0.0.1:8000/auth/login/ and login with the credentials served in the step number 7 of setup:

1.1 Copy the token value presented in the Endpoint response.

2.Paste the token value in the {{token}} placeholder in Header section of the first EP called "Create Task".

2.1 After that, just click in send button to create a new Task.

3. We can get all the previous tasks created with the EP called "Get Task Collection". Query param "field" is used to select only useful fields and reduce the payload charge times and "search" to lookup by username.

4. All the other EP (Get Instance Task, Edit Task, and Delete task) follow the same logic as the above. Just modify the UUID placeholder with the ID of the desired task to edit, get, or delete.