code build to create lambda layer - cannot find module - aws-lambda

Question

I want package a lambda layer using codebuild.
My codebuild buildspec is as follows:
version: 0.2
phases:
install:
runtime-versions:
nodejs: 10
commands:
- npm init -y
- npm install --save middy
artifacts:
files:
- 'node_modules/**/*'
- 'package-lock.json'
- 'package.json'
This saves a nodejs.zip folder to my s3 bucket
the resulting zip file looks like this:
package.json is as follows:
{
"name": "src",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"middy": "^0.30.4"
}
}
however when I add this layer to my lambda (node10.x)
and import my mods:
'use strict';
var AWS = require('aws-sdk');
const middy = require('middy')
const { cors } = require('middy/middlewares')
Returns the following error:
{
"errorType": "Runtime.ImportModuleError",
"errorMessage": "Error: Cannot find module 'middy'\nRequire stack:\n- /var/task/function_code/verify_zipcode.js\n- /var/runtime/UserFunction.js\n- /var/runtime/index.js",
"trace": [
"Runtime.ImportModuleError: Error: Cannot find module 'middy'",
"Require stack:",
"- /var/task/function_code/verify_zipcode.js",
"- /var/runtime/UserFunction.js",
"- /var/runtime/index.js",
" at _loadUserApp (/var/runtime/UserFunction.js:100:13)",
" at Object.module.exports.load (/var/runtime/UserFunction.js:140:17)",
" at Object.<anonymous> (/var/runtime/index.js:43:30)",
" at Module._compile (internal/modules/cjs/loader.js:956:30)",
" at Object.Module._extensions..js (internal/modules/cjs/loader.js:973:10)",
" at Module.load (internal/modules/cjs/loader.js:812:32)",
" at Function.Module._load (internal/modules/cjs/loader.js:724:14)",
" at Function.Module.runMain (internal/modules/cjs/loader.js:1025:10)",
" at internal/main/run_main_module.js:17:11"
]
}
Adding the envoronment variable:
NODE_PATH : ./:/opt/node_modules gave my lambda access to my layers, but lost the context of aws-sdk
After adding the env var I get the following error:
{
"errorType": "Runtime.ImportModuleError",
"errorMessage": "Error: Cannot find module 'aws-sdk'\nRequire stack:\n- /var/task/function_code/verify_zipcode.js\n- /var/runtime/UserFunction.js\n- /var/runtime/index.js",
"trace": [
"Runtime.ImportModuleError: Error: Cannot find module 'aws-sdk'",
"Require stack:",
"- /var/task/function_code/verify_zipcode.js",
"- /var/runtime/UserFunction.js",
"- /var/runtime/index.js",
" at _loadUserApp (/var/runtime/UserFunction.js:100:13)",
" at Object.module.exports.load (/var/runtime/UserFunction.js:140:17)",
" at Object.<anonymous> (/var/runtime/index.js:43:30)",
" at Module._compile (internal/modules/cjs/loader.js:956:30)",
" at Object.Module._extensions..js (internal/modules/cjs/loader.js:973:10)",
" at Module.load (internal/modules/cjs/loader.js:812:32)",
" at Function.Module._load (internal/modules/cjs/loader.js:724:14)",
" at Function.Module.runMain (internal/modules/cjs/loader.js:1025:10)",
" at internal/main/run_main_module.js:17:11"
]
}
Is there a way to use both the native aws-sdk and my layers? Or do I need to use an aws-sdk layer anytime I use other custom layers?

Answer 1

The directory structure of a node.js layer (nodejs.zip in your example) should be:
├── nodejs
└── package.json
└── node_modules
└── middy(version z.z.z)
Update your buildspec file to add a parent nodejs folder:
version: 0.2
phases:
install:
runtime-versions:
nodejs: 10
commands:
- mkdir nodejs # NEW LINE
- cd nodejs # NEW LINE
- npm init -y
- npm install bcrypt
artifacts:
files:
- 'nodejs/**/*' # CHANGE LINE
- 'package.json'
and remove the environment variable:
NODE_PATH