unveil

README

unveil

---

unveil is a command-line tool to extract values from configuration files (JSON, YAML, TOML, INI, .env/key-value files) and expose them as environment variables. It is designed for scripting and container environments where you want to unveil secrets or config values and pass them to processes in a standardized KEY=VALUE format.

Features

• Supports multiple file formats:
  • JSON
  • YAML
  • TOML
  • INI
  • key=value files (including .env with export KEY=VAL)
• Flexible key selectors:
  • Dot notation for nested fields: server.host
  • Array index: servers.0.host
  • Array filter: servers.[name=db].port
• Output options:
  • Plain KEY=VALUE
  • With export prefix (--export)
  • Optional quoting (none, single, double, json)
• Atomic file output with --output (safe for CI/CD)
• Multiple extractions in one command (dynamic groups)

Installation

go install github.com/gi8lino/unveil@latest

or download binaries from Releases.

Usage

unveil [flags]

Examples

Extract a single value from JSON:

unveil \
  --json.db.path=./config.json \
  --json.db.select=database.user \
  --json.db.as=DBUSER

Output:

DBUSER=alice

Extract from YAML and TOML, with quoting:

unveil \
  --yaml.srv.path=./app.yaml \
  --yaml.srv.select=server.host \
  --yaml.srv.as=HOST \
  --yaml.srv.quote=single \
  --toml.t.path=./cfg.toml \
  --toml.t.select=server.port \
  --toml.t.as=PORT

Output:

HOST='localhost'
PORT=8080

Write directly to a file instead of stdout:

unveil --file.env.path=.env --file.env.select=TOKEN --file.env.as=API_TOKEN --output=out.env

Result (out.env):

API_TOKEN=secret

With --export:

export API_TOKEN=secret

Supported Flags

• --quote MODE — global quote mode for all values One of: none, single, double, json
• --output FILE — write results atomically to FILE instead of stdout
• --export — prefix each line with export

Each extractor group (json, yaml, toml, ini, file) supports:

• --<group>.<id>.path=PATH (required)
• --<group>.<id>.select=KEY (required)
• --<group>.<id>.as=VAR (optional, defaults to uppercase ID)
• --<group>.<id>.quote=MODE (optional override)

Development

Run unit tests:

go test ./...

Lint:

golangci-lint run

License

Apache 2.0 -- see LICENSE