Optionally support prebuilds for libc and arm flavors

README.md

@@ -36,6 +36,20 @@ without having to compile on install time AND will work in both node and electro
 
 Users can override `node-gyp-build` and force compiling by doing `npm install --build-from-source`.
 
+## Supported prebuild names
+
+If so desired you can bundle more specific flavors, for example `musl` builds to support Alpine, or targeting a numbered ARM architecture version.
+
+These prebuilds can be bundled in addition to generic prebuilds; `node-gyp-build` will try to find the most specific flavor first. In order of precedence:
+
+- If `arch` is `'arm'` or `'arm64'`:
+  - `${platform}${libc}-${arch}-v${arm_version}`
+  - `${platform}-${arch}-v${arm_version}`
+- `${platform}${libc}-${arch}`
+- `${platform}-${arch}`
+
+The `libc` flavor and `arm_version` are auto-detected but can be overridden through the `LIBC` and `ARM_VERSION` environment variables, respectively.
+
 ## License
 
 MIT

index.js

@@ -9,6 +9,8 @@ var abi = process.versions.modules // TODO: support old node where this is undef
 var runtime = isElectron() ? 'electron' : 'node'
 var arch = os.arch()
 var platform = os.platform()
+var libc = process.env.LIBC || (isAlpine(platform) ? 'musl' : 'glibc')
+var armv = process.env.ARM_VERSION || (arch === 'arm64' ? '8' : process.config.variables.arm_version) || ''
 
 module.exports = load
 
@@ -30,16 +32,28 @@ load.path = function (dir) {
   var debug = getFirst(path.join(dir, 'build/Debug'), matchBuild)
   if (debug) return debug
 
-  var prebuild = getFirst(path.join(dir, 'prebuilds/' + platform + '-' + arch), matchPrebuild)
-  if (prebuild) return prebuild
+  var names = [platform + '-' + arch]
+  if (libc) names.push(platform + libc + '-' + arch)
 
-  var napiRuntime = getFirst(path.join(dir, 'prebuilds/' + platform + '-' + arch), matchNapiRuntime)
-  if (napiRuntime) return napiRuntime
+  if ((arch === 'arm' || arch === 'arm64') && armv) {
+    names.forEach(function (name) {
+      names.push(name + '-v' + armv)
+    })
+  }
+
+  // Find most specific flavor first
+  for (var i = names.length; i--;) {
+    var prebuild = getFirst(path.join(dir, 'prebuilds/' + names[i]), matchPrebuild)
+    if (prebuild) return prebuild
+
+    var napiRuntime = getFirst(path.join(dir, 'prebuilds/' + names[i]), matchNapiRuntime)
+    if (napiRuntime) return napiRuntime
 
-  var napi = getFirst(path.join(dir, 'prebuilds/' + platform + '-' + arch), matchNapi)
-  if (napi) return napi
+    var napi = getFirst(path.join(dir, 'prebuilds/' + names[i]), matchNapi)
+    if (napi) return napi
+  }
 
-  throw new Error('No native build was found for runtime=' + runtime + ' abi=' + abi + ' platform=' + platform + ' arch=' + arch)
+  throw new Error('No native build was found for runtime=' + runtime + ' abi=' + abi + ' platform=' + platform + libc + ' arch=' + arch)
 }
 
 function getFirst (dir, filter) {
@@ -73,3 +87,7 @@ function isElectron () {
   if (process.env.ELECTRON_RUN_AS_NODE) return true
   return typeof window !== 'undefined' && window.process && window.process.type === 'renderer'
 }
+
+function isAlpine (platform) {
+  return platform === 'linux' && fs.existsSync('/etc/alpine-release')
+}