Lecture Notes: Parsing YAML Files with YQ

Introduction to YQ Templating

• Purpose: To learn YQ templating and how to read YAML files.
• Context: YAML files are prevalent in DevOps for configuration.
• Goal: To simplify development/modifications using Python or other languages.

Recap of Previous Sessions

• Covered Topics:
  • Reading and writing YAML files with Python.
  • Inserting data into MySQL databases using Python.

Today's Focus

• Installing YQ:
  • Quick installation on Ubuntu and Windows.
• Examples:
  • Reading YAML files.
  • Creating variables from YAML files.

YAML File Structures

• Key Types:
  • Key-Value Pairs: Basic association (e.g., pi: 3.14).
  • Arrays/Lists: Collection of similar objects (e.g., tables array).
  • Dictionaries: Maps or collections of key-value pairs (e.g., Xmas 50 map).

Practical Examples with YQ

• Installation Steps:
  • Ubuntu: Install using brew or directly using wget.
  • Windows: Download exe, add to environment path variable.
• Usage:
  • Use YQ commands to read different data types in YAML.
  • Extract values and store them for further use (e.g., in Azure pipelines).

Working with Arrays and Dictionaries

• Array Handling:
  • Retrieve array elements and values through correct indexing.
• Dictionary Access:
  • Navigate nested dictionaries to fetch specific data.

Additional Resources and Documentation

• GitHub Repository: Contains YQ templating examples.
• Command Syntax: Detailed explanation of commands used to parse YAML.

Conclusion

• Understanding YAML Parsing:
  • Important for handling complex configurations in DevOps.
• Further Learning:
  • Explore YQ GitHub for more examples and development insights.
• Engagement:
  • Encouragement to subscribe and comment for more support.
• Summary: Overview of YQ usage through examples and commands.

• If there are any questions or challenges while working with YAML and YQ, viewers are encouraged to comment and seek further clarification.