feat: detect invalid binaries and show warning

package.json

@@ -53,13 +53,13 @@
   },
   "dependencies": {
     "@babel/parser": "7.16.8",
+    "@netlify/binary-info": "^1.0.0",
     "@netlify/esbuild": "0.14.25",
     "@vercel/nft": "^0.20.0",
     "archiver": "^5.3.0",
     "common-path-prefix": "^3.0.0",
     "cp-file": "^9.0.0",
     "del": "^6.0.0",
-    "elf-cam": "^0.1.1",
     "end-of-stream": "^1.4.4",
     "es-module-lexer": "^0.10.0",
     "execa": "^5.0.0",

src/runtimes/detect_runtime.ts

@@ -1,11 +1,13 @@
 import type { Buffer } from 'buffer'
 
-import { detect, Runtime } from 'elf-cam'
+import { detect, Runtime, Arch, Platform, BinaryInfo } from '@netlify/binary-info'
 
 import { cachedReadFile, FsCache } from '../utils/fs.js'
 
 import type { RuntimeName } from './runtime.js'
 
+const isValidFunctionBinary = (info: BinaryInfo) => info.arch === Arch.Amd64 && info.platform === Platform.Linux
+
 // Try to guess the runtime by inspecting the binary file.
 export const detectBinaryRuntime = async function ({
   fsCache,
@@ -20,15 +22,27 @@ export const detectBinaryRuntime = async function ({
     // We're using the Type Assertion because the `cachedReadFile` abstraction
     // loses part of the return type information. We can safely say it's a
     // Buffer in this case because we're not specifying an encoding.
-    const binaryType = detect(buffer as Buffer)
+    const binaryInfo = detect(buffer as Buffer)
+
+    if (!isValidFunctionBinary(binaryInfo)) {
+      console.warn(`
+Found incompatible prebuilt function binary in ${path}.
+The binary needs to be built for Linux/Amd64, but it was built for ${Platform[binaryInfo.platform]}/${
+        Arch[binaryInfo.arch]
+      }`)
+
+      return undefined
+    }
 
-    switch (binaryType) {
+    switch (binaryInfo.runtime) {
       case Runtime.Go:
         return 'go'
       case Runtime.Rust:
         return 'rs'
       default:
         return undefined
     }
-  } catch {}
+  } catch {
+    // Possible errors are: non binary files, arch/platforms not supported by binary-info, path is directory
+  }
 }

tests/main.js

@@ -2692,3 +2692,14 @@ test('listFunctionsFiles includes in-source config declarations', async (t) => {
     t.is(func.schedule, '@daily')
   })
 })
+
+test('listFunctionsFiles does not include wrong arch functions and warns', async (t) => {
+  sinon.spy(console, 'warn')
+  const functions = await listFunctionsFiles(join(FIXTURES_DIR, 'wrong-prebuilt-architecture'))
+
+  t.is(functions.length, 0)
+  t.is(console.warn.called, true)
+  t.is(console.warn.calledWith(sinon.match(/Darwin\/Arm64/)), true)
+
+  console.warn.restore()
+})