Findner

This is a back end project that works with Partners; creating, loading, and finding their nearest given a coordinations. It uses FastAPI and PostgreSQL.

Find + Partner -> 🔥Findner🔥

Demo

Link to video in Youtube, Aparat

Installation

0. Open your terminal (I used bash)
1. Clone the project

git clone https://github.com/sananqsh/Findner.git

3. Change directory to the project root

cd Findner

4. Make .env file (.env file should contain the necessary environment variables for the PostgreSQL database connection)

cp .env.example .env

Create PostgreSQL user and database

You need to create a PostgreSQL user that you can use to interact with your database. You can do this from the PostgreSQL shell. The following steps are for a Linux-based system:

• Log into PostgreSQL shell

sudo -u postgres psql

• Create a new PostgreSQL user

CREATE USER yourusername WITH PASSWORD 'yourpassword';

• Create a new database

CREATE DATABASE yourdbname;

• Grant privileges to your user for the new database

GRANT ALL PRIVILEGES ON DATABASE yourdbname TO yourusername;

Sometimes PostgreSQL is configured to disallow non-superusers from creating databases or schema, and you might need to modify these configurations to suit your needs, or alter your user role to super user:

ALTER USER yourusername WITH SUPERUSER

# if you want to remove superuser privileges, you can do it with:
# ALTER USER yourusername WITH NOSUPERUSER;

• Exit the PostgreSQL shell

\q

For the tutorial we went through, the .env should look like this (based on our docker-compose, the host would be db):

DATABASE_USER=yourusername
DATABASE_PASSWORD=yourpassword
DATABASE_NAME=yourdbname
DATABASE_HOST=db

---

- Run this

  psql -U yourusername -d yourpassword

If got this error: psql: error: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: FATAL: Peer authentication failed for user "yourusername"

Make sure the postgres service is up: sudo service postgresql status

Try locating pg_conf.hba; its usual locations are /etc/postgresql/[version]/main/pg_hba.conf and /var/lib/pgsql/data/pg_hba.conf you need to change the line:

local   all             all                                peer

to

local   all             all                                md5

and then restart the service:

sudo service postgresql restart

5. Run docker-compose (see this and this if not installed; compose version has to be at least 1.25.5)

The --build is only for first time docker-composing.

docker-compose up -d --build

6. You can call APIs from your local! See the /docs route for Swagger documentations of APIs (for example if the project is on local: http://127.0.0.1:8000/docs)

Tests

In order to run tests, you have to have your containers up if they're not:

This is assuming you've already built the services with --build option

docker-compose up -d

Then docker exec into to a web application instance in interactive mode and run bash:

docker exec -ti findner_web1_1 bash

Run the tests:

behave -k tests/partner_api_tests/ 

And for OpenWeatherApi tests:

behave -k tests/weather_api_tests/ 

Deployment

The docker-compose.yml is provided in a way that we can deploy a new version of the web application without downtime.

There are other ways to achieve zero-downtime deployment, including the use of Docker Swarm or Kubernetes. However, these methods can be complex and may require additional resources.

The docker-compose creates two instances of the web app with a load balancer (NGINX) in front of them (the number of instances can increase based on our need).

A new version of the application could be deployed to one instance at a time, ensuring that at least one instance is always available to handle incoming requests. My approach for introducing new version of the code is to build the application's Docker image with the new version of the code, then use docker-compose up --no-deps --build web1 to update web1 and docker-compose up --no-deps --build web2 to update web2, ensuring that at least one of them is always running.