https://github.com/shashanksrivatsarao/docker-compose-practice

https://github.com/shashanksrivatsarao/docker-compose-practice

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• Host: GitHub
• URL: https://github.com/shashanksrivatsarao/docker-compose-practice
• Owner: ShashankSrivatsaRao
• Created: 2024-12-02T13:38:51.000Z (about 1 month ago)
• Default Branch: master
• Last Pushed: 2024-12-02T13:42:02.000Z (about 1 month ago)
• Last Synced: 2024-12-02T14:44:13.668Z (about 1 month ago)
• Language: Python
• Size: 3.91 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: Readme.md

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README

        
#  TASK  :TO CREATE 2 CONTAINERS AND ESTABLISH CONNECTION

## This outlines the steps I took to complete the tasks and demonstrate the basic functionality of Docker Compose. 

**Description** : I was tasked with spinning up two containers, Flask and SQL, and connecting the Flask container to the database container.

### Step 1: 

**I created a folder for my project and initialized it with git init.**

 ```bash

 mkdir flask-app

 cd flask-app

 git init

 ```

### Step 2

 **I created an app.py file with a basic Flask program to display "Hello, World," and then wrote a Dockerfile to build an image and run a container with all required dependencies and port mappings.**

   

 ```bash

touch app.py  # Created a hello world message using Flask

touch Dockerfile # Added a Dockerfile to containerize the app

touch requirements.txt # Listed all dependencies (Flask)

# Built and ran the Docker image

docker build -t flaskapp:latest .

docker run -p 3000:3000 flaskapp:latest

# Accessed the app at 127.0.0.1:3000 to verify the hello world message.

```

 ### Step 3 

 **1.I updated the app.py file to establish database connections.**

**2.Created a docker-compose.yml file to launch multiple containers.**

***NOTE: I connected to the database container by using the service name as the DB_HOST in the environment variables.***

 ```bash

touch docker-compose.yml

# Added all database content to the database container using PostgreSQL.

# Built the previously written Dockerfile into a container running the Flask app.

```

 ***Challenges: In the build section of the flask-app container in the YAML file, I added a dot to indicate that the build should use the current Dockerfile.***

***The database container's name is crucial for communication.***

 ### Step 4 

 **Executed all containers simultaneously with Docker Compose.**

 ```bash

 docker compose build

 docker compose up

 ```

### Challenges: ### 

 **Configuring the correct Python file name in the Dockerfile RUN command.**

 **2>Build: This command is utilized to create an image from a Dockerfile located in the current directory as specified in the YAML file.**

 **3>Verified the connection by accessing the container and executing the command.**

 

   ```

   docker exec  -it bash

   psql -U testuser -d testdb 

   ```  

 **3> I was unable to access the database within the psql container. So took the following steps.**

 

 ```bash

 docker exec  -it bash

 #root@psql -U rootuser -d testdb

 #testdb: /l  this will list the databses and the tables in the server

 ```

 

 ## Conclusion:

 **1. Acquired knowledge on how to connect containers to one another using the Docker Compose YAML file.  

2. Understood the significance of port mapping and the process of writing a Dockerfile.  

3. Learned the principles of Docker Compose.**

 # THANK YOU SHASHANK S