Level 3 Report

3 / 3 / 2024

Level 3 Report

Task1- OSI with Switching, Routing, Handshakes, Ip Addressing

The OSI (Open Systems Interconnection) model is a framework that divides network communication into seven layers, each with specific tasks

1 Physical Layer: Handles the actual transmission of data over the network medium. Protocols: USB, Ethernet

2 Data Link Layer: Manages data flow and error correction between devices on the same network. Protocols: Ethernet, Wi-Fi

3 Network Layer: Addresses and routes data between different networks and subnets. Protocols: IP (IPv4 and IPv6)

4 Transport Layer: Ensures end-to-end communication, data segmentation, and error recovery. Protocols: TCP, UDP

5 Session Layer: Establishes, maintains, and terminates communication sessions between applications. Protocols: NetBIOS, RPC.

6 Presentation Layer: Translates, encrypts, and compresses data for compatibility. Protocols: GIF, JPEG

7 Application Layer: Provides network services directly to user applications and manages application-specific protocols. Protocols: Protocols: HTTP, DNS

1 Switching: Happens at Layer 2 (Data Link). It directs data within a local network based on MAC addresses.

2 Routing: Occurs at Layer 3 (Network). Routers guide data between different networks or subnets.

3 IP Addressing: Managed at Layer 3 (Network), assigning unique IP addresses for devices, like IPv4 and IPv6.

4 Handshakes: Occurs at Layer 4(Transport), Eg: TCP's three-way handshake for connection setup.

Task3- Sockets!

1 In this task, I used the features of nodejs to build a real time chat application.

2 The messages in the application get updated without refreshing the webpage. It is done with the help of socket.io library.

Code

Task7- Webscraping and Automation

1 In this task, I automated an instagram account to follow a account, send a message and like a post of the followed account.

2 This was done using the Instabot package.

3 Update : This method is dependent on the instagram's policy and may or may not work. (It worked for me)

Code

Task5- Docker

In this task, I created a Docker container every time when a push to production branch is made on a (VCS).

1 A Dockerfile was created specifying image configurations.

2 A GitHub Actions workflow (build.yml) was defined to trigger on pushes to the production branch.

3 Workflow steps included code checkout, Docker Hub login, image building, and pushing to Docker Hub.

Code

Task6-Docker file spyware

• In this task, I wrote a dockerfile spyware that constantly monitors a folder and sends all images posted into that folder.

Steps

• Build the docker image.

docker build -t image-monitor .

• Run the container.

docker run -d --name img99 image-monitor

• Verify

Code

Task2-Serverless

In this task, I created a server which supports running serverless nodejs code which supports cold starts, terminates an app when not in use, and boots it when a request is made.

Deployment Steps

• Lambda Setup: Created a Lambda function with Node.js runtime and appropriate IAM role. Initialized resources outside the handler and implemented cleanup for efficient execution.

• API Gateway: Created an API, added a resource associated with the Lambda function, and deployed for public access.

• Monitoring and Optimization: Monitored Lambda function executions with CloudWatch Logs and explored techniques to further decrease cold start times.

• Testing confirmed successful invocation of the Lambda function through the API Gateway URL. Cold starts were observed after periods of inactivity but mitigated by the implemented initialization and cleanup processes.