Debug YAML Syntax Errors in Helm Values Files

YAML Syntax Errors in Helm Values

Before Helm can process your values file, it must be valid YAML. The Helm Values Validator provides detailed error messages for syntax issues, helping you pinpoint and fix problems quickly.

Common YAML Errors

1. Indentation with tabs (YAML requires spaces):

service:
→type: ClusterIP    # Tab character - INVALID
  port: 80           # Spaces - valid

Error: "bad indentation of a mapping entry"

2. Missing space after colon:

service:
  type:ClusterIP     # Missing space - INVALID
  port: 80

3. Unquoted special characters:

annotations:
  description: Use *asterisks* for emphasis  # May cause issues
  regex: [a-z]+                              # Interpreted as array!

4. Inconsistent indentation:

image:
  repository: nginx
   tag: "1.25"     # 3 spaces instead of 2 - INVALID

5. Duplicate keys:

service:
  type: ClusterIP
  port: 80
  port: 8080      # Duplicate key - second wins silently

How the Validator Helps

The YAML parser (js-yaml) provides line numbers and descriptive error messages:

YAMLException: bad indentation of a mapping entry (3:1)

The validator displays these errors prominently before any Helm-specific validation, since syntax errors must be fixed first.

YAML Best Practices for Helm Values

1. Use 2-space indentation (consistent with Helm conventions)
2. Quote string values that look like numbers or booleans
3. Never use tabs for indentation
4. Use a YAML linter in your editor (VS Code YAML extension)
5. Validate before committing using this tool or yamllint

Multi-Line Strings

# Literal block (preserves newlines)
description: |
  This is a multi-line
  description that preserves
  line breaks.

# Folded block (joins lines)
summary: >
  This is a long summary
  that gets folded into
  a single line.