Build a Simple Go HTTP Client

This challenge will guide you through creating a basic HTTP client in Go. You'll learn how to make HTTP requests, handle responses, and process data from a web server. This is a fundamental skill for interacting with web APIs and services.

Problem Description

Your task is to implement a Go program that can fetch data from a given URL. The program should be able to send a GET request to a specified URL, retrieve the response body, and then print the content of the response. You should also handle potential errors that might occur during the HTTP request.

Key Requirements:

• Make a GET request to a provided URL.
• Read the entire response body.
• Print the response body to standard output.
• Handle potential network errors (e.g., invalid URL, connection refused).
• Handle potential HTTP errors (e.g., 404 Not Found, 500 Internal Server Error).

Expected Behavior:

• If the request is successful (HTTP status code 2xx), print the response body.
• If an error occurs during the request or an HTTP error status is returned, print an informative error message to standard error.

Edge Cases:

• What happens if the URL is malformed?
• What happens if the server is unreachable?
• What happens if the server returns a non-200 status code?
• What happens if the response body is empty?

Examples

Example 1: Input: https://jsonplaceholder.typicode.com/todos/1 Output:

{
  "userId": 1,
  "id": 1,
  "title": "delectus aut autem",
  "completed": false
}

Explanation: The program successfully makes a GET request to the provided URL, retrieves the JSON data, and prints it to standard output.

Example 2: Input: https://example.com/nonexistent-page Output:

Error: HTTP request failed: status code 404 Not Found

Explanation: The program encounters a 404 Not Found error and prints an appropriate error message to standard error.

Example 3: Input: invalid-url Output:

Error: HTTP request failed: invalid URL: parse "invalid-url": for URL must have a scheme matching "http" or "https"

Explanation: The program detects an invalid URL format and prints a parsing error message to standard error.

Constraints

• The URL will be provided as a string argument to your program.
• You are expected to use Go's standard net/http package for making requests.
• The response body is not expected to exceed 1MB in size for typical successful requests in this challenge.
• The program should execute within a reasonable time frame (e.g., a few seconds for network operations).

Notes

• You will likely need to import the net/http and io packages.
• Consider using http.Get() for simplicity in making GET requests.
• Remember to read the response body completely before the response connection is closed. The io.ReadAll() function is very useful here.
• Pay attention to the resp.StatusCode to check for HTTP errors.
• For printing errors, fmt.Errorf and log.Fatal or fmt.Fprintln(os.Stderr, ...) are good options.