configbuilder

configbuilder — mustache-template config generator

import "github.com/downsized-devs/sdk-go/configbuilder"

Stability: Stable — see STABILITY.md

Renders mustache templates into runtime config files at startup. Useful when you want a single source-of-truth template that fans out into per-environment JSON/YAML files.

Features

• BuildConfig(opts Options) — render and write
• Mustache placeholders, optionally fed by viper or environment

Installation

go get github.com/downsized-devs/sdk-go/configbuilder

Quick Start

import "github.com/downsized-devs/sdk-go/configbuilder"

b := configbuilder.Init()
b.BuildConfig(configbuilder.Options{
    TemplatePath: "config/app.json.tmpl",
    OutputPath:   "config/app.json",
    Data:         map[string]any{ "env": "prod", "host": os.Getenv("APP_HOST") },
})

API Reference

Examples

Generate per-environment config from CI

ENV=staging go run ./tools/build_config

b.BuildConfig(configbuilder.Options{
    TemplatePath: fmt.Sprintf("config/%s.json.tmpl", os.Getenv("ENV")),
    OutputPath:   "config/runtime.json",
    Data:         map[string]any{
        "redisAddr": os.Getenv("REDIS_ADDR"),
        "dbDSN":     os.Getenv("DB_DSN"),
    },
})

Error Handling

BuildConfig returns errors from missing templates and write failures. Surface them at process startup — failing to build config should be fatal.

Dependencies

• Internal: files
• External: github.com/cbroglie/mustache, github.com/spf13/viper

Testing

go test ./configbuilder/...

Two test files (unit + integration).

Contributing

See CONTRIBUTING.md.

Related Packages

• configreader — the read side: parses the file configbuilder produces.
• files — used internally for path checks.