kzdiff/src/kustomize.ts

CLI tool for comparing Kustomize build results between branches

import { $ } from "bun"
import { mkdtemp } from "node:fs/promises"
import { join } from "node:path"
import { tmpdir } from "node:os"
import { createDebugLogger } from "./debug"

interface ErrorWithStderr extends Error {
	stderr?: string | Buffer
}

interface BuildOptions {
	ref?: string
	remote?: string
}

export async function kustomizeBuildToTmp(
	kustomizePath: string,
	filename: "before.yaml" | "after.yaml",
	options?: string[],
	buildOptions?: BuildOptions,
): Promise<string> {
	const debug = createDebugLogger("kustomizeBuildToTmp")
	const tempDir = await mkdtemp(join(tmpdir(), "kustomize-build-"))
	const outputPath = join(tempDir, filename)

	debug(`Created temp dir: ${tempDir}`)
	debug(`Output path: ${outputPath}`)

	let targetPath = kustomizePath

	try {
		// If remote is specified, use Kustomize's native remote support
		if (buildOptions?.remote) {
			// Format: https://github.com/owner/repo//path/to/dir?ref=branch&submodules=false
			const cleanRemote = buildOptions.remote.replace(/\.git$/, "")
			const cleanPath = kustomizePath.replace(/^\.?\//, "")
			targetPath = `${cleanRemote}//${cleanPath}`

			// Add query parameters
			const queryParams = []
			if (buildOptions.ref) {
				queryParams.push(`ref=${buildOptions.ref}`)
			}
			queryParams.push("submodules=false")

			targetPath += `?${queryParams.join("&")}`

			debug(`Using remote URL: ${targetPath}`)
		} else {
			debug(`Using local path: ${targetPath}`)
		}

		const args = ["kustomize", "build"]

		if (options && options.length > 0) {
			args.push(...options)
			debug(`Additional options: ${options.join(" ")}`)
		}

		args.push(targetPath)

		debug(`Running command: ${args.join(" ")}`)

		const result = await $`${args}`.quiet()
		await Bun.write(outputPath, result.stdout)

		debug(`Build successful, wrote ${result.stdout.length} bytes to ${outputPath}`)

		return outputPath
	} catch (error) {
		// Check if this is a remote build and the directory doesn't exist
		if (buildOptions?.remote && error instanceof Error && "stderr" in error) {
			const errorWithStderr = error as ErrorWithStderr
			if (errorWithStderr.stderr) {
				const errorMessage = errorWithStderr.stderr.toString().toLowerCase()
				const notFoundPatterns = ["does not exist", "no such file or directory"]

				const isNotFound = notFoundPatterns.some((pattern) => errorMessage.includes(pattern))

				if (isNotFound) {
					debug(`Remote directory not found, creating empty file at ${outputPath}`)
					await Bun.write(outputPath, "")
					return outputPath
				}
			}
		}

		console.error(`[kustomizeBuildToTmp] Error: ${error}`)
		if (error instanceof Error && "stderr" in error) {
			const errorWithStderr = error as ErrorWithStderr
			if (errorWithStderr.stderr) {
				console.error(`[kustomizeBuildToTmp] stderr: ${errorWithStderr.stderr}`)
			}
		}
		throw new Error(`Failed to run kustomize build: ${error}`)
	}
}