Is the output valid YAML?

Yes. The generator uses two-space indentation, the standard YAML convention, with no tabs (which YAML forbids). Keys map to values via colon-space, lists use hyphen-space, and special string values are quoted so they parse as strings rather than booleans or numbers.

How are data types represented in YAML?

YAML infers types from syntax: true and false are booleans, bare digits are numbers, null or ~ is null, and other bare words are strings. Strings that look like booleans or numbers are quoted to preserve them, which this tool does automatically.

Can I use this for Kubernetes manifests?

The Kubernetes preset emits a manifest-shaped document with apiVersion, kind, metadata, and spec sections. It is structurally representative for testing parsers and templating, though you should validate against the real schema before applying it to a cluster.

Why two-space indentation?

YAML uses indentation to express structure and explicitly disallows tab characters for indentation. Two spaces per level is the near-universal convention in Kubernetes, CI, and tooling configs, so the generator follows it for maximum compatibility.

Mock YAML Generator — Gera Tools

Mock YAML Generator

YAML drives a huge amount of modern tooling: Kubernetes manifests, CI pipelines, and infrastructure configuration all live in YAML files. When you are building or testing a parser, a templating layer, or a config-driven feature, you need valid sample documents that exercise nested maps, lists, and mixed value types. This tool generates that YAML for you.

How it works

The generator builds a tree of values and serializes it with two-space indentation, the standard YAML convention (tabs are forbidden in YAML indentation). Maps emit key: value pairs, lists emit - item entries, and nested structures indent one level deeper per depth.

Type handling follows YAML’s inference rules. Booleans render as true/false, numbers render bare, and null renders as null. Crucially, any string that looks like a boolean, number, or null is wrapped in quotes so the parser keeps it as a string. Three presets shape the output: a generic application config, a Kubernetes-style manifest (apiVersion, kind, metadata, spec), and a CI pipeline (stages, jobs, steps).

Tips and notes

Validate output with a YAML linter or yaml.safe_load to confirm it parses; it should round-trip cleanly.
The Kubernetes preset is structurally representative but not schema-validated, so check it against the real resource schema before applying.
Quoting of ambiguous strings (for example "yes", "123") prevents YAML from coercing them into booleans or numbers.
Increase list sizes to test how your parser or UI handles longer sequences.