Tasks - Docker

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1. Install Docker on your local machine. Verify the installation by running the hello-world container.
2. Pull the nginx image from Docker Hub and run it as a container. Map port 80 of the container to port 8080 of your host.
3. Create a Dockerfile for a simple Node.js application that serves “Hello World” on port 3000. Build the Docker image with tag my-node-app and run a container. Below is the sample index.js file.

const express = require('express');const app = express();app.get('/', (req, res) => {    res.send('Hello World');});app.listen(3000, () => {    console.log('Server is running on port 3000');});

4. Tag the Docker image my-node-app from Task 3 with a version tag v1.0.0.

5. Push the tagged image from Task 4 to your Docker Hub repository.

6. Run a container from the ubuntu image and start an interactive shell session inside it. You can run commands like ls, pwd, etc.

7. Create a Dockerfile for a Go application that uses multi-stage builds to reduce the final image size. The application should print “Hello Docker”. Sample Go code.

package mainimport "fmt"func main() {    fmt.Println("Hello Docker")}

8. Create a Docker volume and use it to persist data for a MySQL container. Verify that the data persists even after the container is removed. Try creating a test db.

9. Create a custom Docker network and run two containers (e.g., nginx and mysql) on that network. Verify that they can communicate with each other.

10. Create a docker-compose.yml file to define and run a multi-container Docker application with nginx as a web server and mysql as a database.

11. Scale the nginx service in the previous Docker Compose setup to run 3 instances.

12. Create a bind mount to share data between your host system and a Docker container running nginx. Modify a file on your host and see the changes reflected in the container.

13. Add a health check to a Docker container running a simple Node.js application. The health check should verify that the application is running and accessible.

Sample Healthcheck API in node.js,

const express = require('express');const app = express();// A simple route to return the status of the applicationapp.get('/health', (req, res) => {    res.status(200).send('OK');});// Example main routeapp.get('/', (req, res) => {    res.send('Hello, Docker!');});// Start the server on port 3000const port = 3000;app.listen(port, () => {    console.log(`App is running on http://localhost:${port}`);});

14. Modify a Dockerfile to take advantage of Docker’s build cache, ensuring that layers that don’t change are reused.

15. Run a PostgreSQL database in a Docker container and connect to it using a database client from your host.

16. Create a custom Docker network and run a Node.js application and a MongoDB container on the same network. The Node.js application should connect to MongoDB using the container name.

const mongoose = require('mongoose');mongoose.connect('mongodb://mongodb:27017/mydatabase', {  useNewUrlParser: true,  useUnifiedTopology: true,}).then(() => {  console.log('Connected to MongoDB');}).catch(err => {  console.error('Connection error', err);});

17. Create a docker-compose.yml file to set up a MEAN (MongoDB, Express.js, Angular, Node.js) stack with services for each component.

18. Use the docker stats command to monitor resource usage (CPU, memory, etc.) of running Docker containers.

docker run -d --name busybox1 busybox sleep 1000docker run -d --name busybox2 busybox sleep 1000

19. Create a Dockerfile for a simple Python Flask application that serves “Hello World”.

20. Configure Nginx as a reverse proxy to forward requests to a Flask application running in a Docker container.

21. Use docker exec to run a command inside a running container.

docker run -d --name ubuntu-container ubuntu sleep infinity

22. Modify a Dockerfile to create and use a non-root user inside the container.

23. Use docker logs to monitor the output of a running container.

24. Use docker system prune to remove unused Docker data (e.g., stopped containers, unused networks).

25. Run a Docker container in detached mode and verify that it’s running in the background.

26. Configure a Docker container to use a different logging driver (e.g., json-file or syslog).

27. Use build arguments in a Dockerfile to customize the build process.

from flask import Flaskapp = Flask(__name__)@app.route('/')def hello_world():    return 'Hello, Docker Build Arguments!'if __name__ == '__main__':    app.run(host='0.0.0.0', port=5000)

28. Set CPU and memory limits for a Docker container (for busybox)

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