Editor support

What it is

A JSON Schema for den.yaml, generated from den’s own config structs. Point your editor’s YAML language server at it and you get key completion, inline descriptions and validation while you write the config: a misspelled key, a wrong service type or a missing required field is underlined before den ever loads the file.

den also checks the file itself, every time it reads it: an error is listed with its line and the file is not applied, and a key den does not know is a warning that names the key you most likely meant (see Editing den.yaml). The schema catches the same mistakes earlier and explains each key as you type it.

Configuration

Nothing in den.yaml changes. Get the schema from the binary you run, so it always matches that version:

den schema > ~/.config/den/den.schema.json

Then reference it on the first line of your den.yaml:

# yaml-language-server: $schema=den.schema.json

The path is relative to the YAML file. The den.yaml in this repository does the same with the committed copy, schema/den.schema.json.

Prerequisites

An editor with the YAML language server:

• VS Code — the YAML extension by Red Hat
• JetBrains IDEs — built in; the $schema comment is honoured
• Neovim — yaml-language-server through your LSP client

Usage

den schema                     # print the schema
den schema > den.schema.json   # save it next to your den.yaml

For contributors

The schema is generated from internal/config/schema.go; descriptions come from the field comments. After changing a config struct, regenerate and commit it — CI fails when the committed file is out of date:

make schema    # runs go generate, writes schema/den.schema.json

Mark a field required with jsonschema:"required" (untagged fields are optional, because many of them can come from a named environment), and list allowed values with jsonschema:"enum=a,enum=b".