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Flint

Flint

Fleet GitOps YAML linter and language server — catches configuration errors, typos, and misplaced keys before fleetctl gitops runs.

Flint autocomplete in VS Code

What it does

  • 18 lint rules — structural validation, semantic checks, security hygiene, deprecation warnings
  • LSP server — real-time diagnostics, completions, hover docs, go-to-definition, code actions
  • --fix — auto-apply safe fixes (typo corrections, deprecated key renames)
  • --format json — structured output for CI pipelines
  • Migration reports — JSON-based migration planning for Fleet version upgrades
  • Agent integration — help-ai progressive discovery for AI-assisted workflows
graph LR
  A[YAML files] --> B[flint check];
  A --> C[flint lsp];
  B --> D[Text / JSON output];
  C --> E[Editor diagnostics];
  C --> F[Completions & hover];
  C --> G[Code actions];

Quick start

# Install (macOS)
curl -fsSL https://raw.githubusercontent.com/headmin/fleet-editor-extensions/main/scripts/install.sh | sh

# Lint a Fleet GitOps repo
flint check .

# Auto-fix safe issues
flint check . --fix

# Initialize configuration
flint init

Editor support

Editor Status Install
VS Code Full LSP Install Flint .vsix from releases
Zed Full LSP Install Flint from Zed extension gallery
Sublime Text Full LSP Install Flint LSP package
JetBrains Full LSP Install Flint plugin
Neovim Full LSP require('flint').setup()

How it works

Flint validates Fleet GitOps YAML at two levels:

  1. Structural — unknown keys, misplaced keys, typo suggestions (Levenshtein distance), missing required fields
  2. Semantic — platform compatibility, label consistency, date formats, secret hygiene, path/glob validation

All validation runs offline with no Fleet server required. The schema is regularly cross-checked against Fleet's Go source for accuracy.