@c6fc/terraform

Link and use the Terraform binary with NPM.

Usage

npm install -p @c6fc/terraform

Set the tf_version config element in your package.json:

"config": {
	"tf_version": "0.15.4"
}

const terraform = require('@c6fc/terraform');

// Importing does nothing on its own -- no disk reads, no download. exec()
// installs the binary on first use, once however many callers ask for it.
await terraform.exec(['apply'], { cwd: './render', stdio: 'inherit' });

That is the whole API for running Terraform. You do not need to await anything first; exec does it for you.

Spawning the binary yourself

isReady exists for the one case exec doesn't cover — when you want the executable and intend to run it your own way. Reading it installs the binary if it isn't cached, and resolves once it's on disk:

const { spawn } = require('child_process');

await terraform.isReady;
spawn(terraform.executablePath, ['plan'], { stdio: 'inherit' });

This package's own bin/index.js is exactly this. Reading executablePath without awaiting isReady first gives you a path that may not exist yet.

Laziness

cacheDir, version and executablePath are accessors: reading any of them resolves tf_version from the nearest package.json, and reading isReady — or calling exec — downloads and hash-verifies the binary if it isn't cached. Destructuring the module (const { isReady } = require('@c6fc/terraform')) therefore starts the download immediately; reach through the module object instead to stay lazy.

Platforms

Linux, on arm, arm64, x32 and x64. Anything else throws when the binary is first needed, naming itself and what is supported, rather than at import.

Exit codes

exec() exits the process with Terraform's own status when Terraform fails, and with 1 when it could not be started at all — a missing binary, or a cwd that does not exist. spawnSync reports status: null in that case, which used to be passed straight to process.exit(), where null means success.

I created this package specifically for use with Sonnetry (@c6fc/sonnetry), but perhaps someone else will find it useful.