Hi, I’m trying to use Knex with SST. It works when I run it locally with

sst start

, but when I run

sst deploy

I get the following error:

2021-06-17T19:18:15.874Z	undefined	ERROR	Uncaught Exception 	{
    "errorType": "Runtime.ImportModuleError",
    "errorMessage": "Error: Cannot find module '../../dialects/postgres/index.js'\nRequire stack:\n- /var/task/invoke.js\n- /var/runtime/UserFunction.js\n- /var/runtime/index.js",
    "stack": [
        "Runtime.ImportModuleError: Error: Cannot find module '../../dialects/postgres/index.js'",
        "Require stack:",
        "- /var/task/invoke.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:999:30)",
        "    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)",
        "    at Module.load (internal/modules/cjs/loader.js:863:32)",
        "    at Function.Module._load (internal/modules/cjs/loader.js:708:14)",
        "    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:60:12)",
        "    at internal/main/run_main_module.js:17:47"
    ]
}

It’s odd because I can see

knex/lib/dialects/postgres/index.js

in my node modules folder. I also have pg installed. I have tried explicitly importing pg in my lambda but to no avail. Here’s the lambda code:

import Knex from "knex";
const pgEnv = process.env.POSTGRES || "";
const config = {
  client: "pg",
  connection: pgEnv,
};
const knex = Knex(config);

I found a webpack workaround for this error is to add the following to the `webpack.config.js`:

module.exports = {
  entry: slsw.lib.entries,
  target: "node",
  externals: { knex: "commonjs knex" },
};

Is there a similar workaround that would be compatible with SST? Thanks!

I think you should be able to label the knex dependency as external using this: https://docs.serverless-stack.com/constructs/Function#externalmodules

Thanks! Have marked it as an external module, but now running into this

Error: Cannot find module 'knex'

Sorry if I’m missing something glaringly obvious.

Can you share the code you're using to specify it?

You probably want the nodeModules option

Looks like you're right, I was thinking of the serverless-esbuild plugin that installs the dependency from node_modules if it's set in externals and referenced in code. It seems here you have to separately specify externalModuels and/or nodeModules

yup I marked both knex and pg as nodeModules and now it’s running fine - thanks!

It's been 5 months but I just want to thank you guys for this thread as its just solved an issue I've been having for hours, Thanks!