14. Parse and Validate Configuration Files
1. Hello, World!
2. Rename Photos by Capture Date
3. Organize Downloads Folder by File Type
4. Delete Old Log Files Automatically
5. Find Duplicate Files Using MD5 Hashing
6. Generate Comprehensive File Inventory
7. Parse Web Server Logs for Performance Metrics
8. Extract Emails, URLs, and Phone Numbers from Text
9. Track Daily and Monthly Active Users from Apache Logs
10. Generate Formatted Text Reports with Column Alignment
11. Analyze Sales Transactions and Generate Revenue Reports
12. Clean and Validate CSV Data
13. Convert JSON API Responses to CSV
14. Parse and Validate Configuration Files
15. Build a CLI Calculator with Argument Parsing
16. Parse and Display Weather Data from JSON
17. Build a Simple Inventory System with Classes
18. Generate Markdown Table from CSV Data
19. Aggregate Sales Data by Time Period
20. Recursive Directory Size Calculator with Filtering
21. Parse and Transform XML Configuration Files
22. Find and Replace Across Multiple Files
23. Build a Simple Template Engine
24. CSV Data Validator with Business Rules
25. Build a Multi-Format Log Analyzer

Challenge

Problem

Production applications rely on configuration files to manage environment-specific settings like database connections, API keys, and feature flags. This drill teaches you to parse YAML config files, validate required fields, check data types, and provide helpful error messages when configuration is invalid. You'll learn YAML parsing, hash validation, type checking, and error handling—essential skills for building reliable Ruby applications and tools.

Difficulty: Beginner

Instructions

  1. Read YAML configuration file (config.yml)
  2. Parse YAML into Ruby hash structure
  3. Validate required fields are present:
    • database.host, database.port, database.name
    • api.endpoint, api.timeout
    • features (hash with at least one boolean feature)
  4. Validate correct data types:
    • database.port must be integer
    • api.timeout must be integer
    • feature flags must be boolean (true/false)
  5. Print validation errors with specific field paths (e.g., 'Missing required field: database.host')
  6. Print success message if valid: 'Configuration valid: X settings loaded'
  7. Exit with status 1 if invalid, status 0 if valid

Files

Editable
Read-only

Hints

Hint 1

YAML.load_file(file) parses YAML and returns a hash

Hint 2

Use hash.dig('key1', 'key2') to safely access nested values

Hint 3

Check if value is nil to detect missing fields

Hint 4

value.is_a?(Integer) checks if value is an integer

Hint 5

[TrueClass, FalseClass].include?(value.class) checks for boolean

Hint 6

Split 'database.port' on '.' to get array of keys for .dig

Hint 7

Recursively count hash values: if value is hash, recurse; else count as 1

Provided Files (Read-only)

1. Valid configuration

Input: 
validate_config('config.yml')
Expected Output: 
Configuration valid: 8 settings loaded

2. Missing required field

Input: 
validate_config('config.yml')
Expected Output: 
Missing required field: database.port

3. Invalid data type for port

Input: 
validate_config('config.yml')
Expected Output: 
Invalid type for database.port: expected Integer, got String
+ 3 hidden test cases