/containers-and-network

1. Create a network 🕸️

docker network create my-net

Always replace my-net with a network name of your choice.

2. Setup containers🚀

Database (postgres)

Pull the latest image from the docker hub.

docker pull postgres

Running the image as a container.

docker run -dit --network=my-net --name=db-container -e POSTGRES_PASSWORD=abc123 postgres

Replace:

1. db-container with the database container name of your choice.

2. abc123 with a password for postgres.

Enter dummy data into the database

CREATE TABLE COMPANY(
   ID INT PRIMARY KEY     NOT NULL,
   NAME           TEXT    NOT NULL,
   AGE            INT     NOT NULL
);
INSERT INTO COMPANY (ID,NAME,AGE) VALUES (1, 'Nick', 29);

Server (FastAPI)

Server code

main.py
# main.py
from fastapi import FastAPI
from .database import conn, cursor

app = FastAPI()

@app.get("/")
def home():
    return {"msg": "Hello"}

@app.get("/company")
def get_company():
    cursor.execute(""" SELECT * FROM company """)
    company = cursor.fetchall()
    return company

Execute the SQL query of your choice as per the available data in the postgres database.

database.py
# database.py
import psycopg

# conn = psycopg.connect("postgresql://postgres:abr123@my_net:5432")
conn = psycopg.connect("dbname='postgres' user='postgres' host='db' password='abc123'")
cursor = conn.cursor()

Here:
dbname='postgres' & user='postgres': postgres is the default database self-created
host='db': db is the database container name on the same network
Use your password instead of abc123

requirements.txt
# requirements.txt
anyio==3.6.2
click==8.1.3
fastapi==0.95.1
h11==0.14.0
idna==3.4
psycopg==3.1.9
psycopg-binary==3.1.9
psycopg-pool==3.1.7
pydantic==1.10.7
sniffio==1.3.0
starlette==0.26.1
typing_extensions==4.5.0
uvicorn==0.22.0
Dockerfile

Build the docker image from the Dockerfile.

# FROM python:3.11
FROM python:3.11.4-alpine3.18

# 
WORKDIR /code

# 
COPY ./requirements.txt /code/requirements.txt

# 
RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt

# 
COPY ./app /code/app

# 
CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "80"]
Build and Run the docker container
docker build -t server-image .

Replace server-image with server image name of your choice.

Running the image as a container.

docker run -dit --network=my-net --name=server-container server-image

Replace:
1. server-container with server container name of your choice.
2. server-image with server name you choose.

3. Ensure both the containers are in the same name network after they are run

docker network inspect my-net

Extras

Check logs of a container

docker logs container-id

Get shell access to a container

docker exec -it container-id bash

GET request using curl

curl 127.0.0.1:8000/company