serverless-plugin-warmup: ImportModuleError

I have a rather simple serverless config, with no other plugins, no package exclude patters, yet I get a ModuleImportError upon deployment. The only potential deviation from the most basic example in the README is that I’ve configured Serverless to build and deploy an image rather than a zip. Any ideas?

{
  "errorType": "Runtime.ImportModuleError",
  "errorMessage": "Error: Cannot find module 's_warmUpPluginWarmer'\nRequire stack:\n- /var/runtime/UserFunction.js\n- /var/runtime/index.js",
  "trace": [
    "Runtime.ImportModuleError: Error: Cannot find module 's_warmUpPluginWarmer'",
    "Require stack:",
    "- /var/runtime/UserFunction.js",
    "- /var/runtime/index.js",
    "    at _loadUserApp (/var/runtime/UserFunction.js:202:13)",
    "    at Object.module.exports.load (/var/runtime/UserFunction.js:242:17)",
    "    at Object.<anonymous> (/var/runtime/index.js:43:30)",
    "    at Module._compile (internal/modules/cjs/loader.js:1085:14)",
    "    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)",
    "    at Module.load (internal/modules/cjs/loader.js:950:32)",
    "    at Function.Module._load (internal/modules/cjs/loader.js:790:12)",
    "    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:76:12)",
    "    at internal/main/run_main_module.js:17:47"
  ]
}

My Serverless config:

provider:
  name: aws
  region: eu-west-1
  memorySize: 1024
  timeout: 900 #sec
  deploymentBucket:
    name: ${opt:stage}-smp-serverless-deployment
  iam:
    role: ${ssm:/${opt:stage}-lambda-serverless-role-arn}
  ecr:
    images:
      appimage:
        path: ./

plugins:
  - serverless-plugin-warmup

functions:
  main:
    name: ${opt:stage}-conv
    environment:
      INPUT_S3_BUCKET: ${ssm:/${opt:stage}-file-upload-bucket-name}
    image:
      name: appimage

custom:
  warmup:
    warmer:
      enabled: true
    package:
      events:
        - schedule: rate(10 minutes)
      concurrency: 10`

Many thanks in advance!

About this issue

Original URL
State: closed
Created 3 years ago
Comments: 30 (11 by maintainers)

Most upvoted comments

Hi @juanjoDiaz, I was facing this same issue but the proposed workaround didn’t work for me. However, I found a fix!

In my case, I’m using both serverless-plugin-warmup for warmups and serverless-esbuild for bundling/minifying.

In the plugins section, if I list serverless-esbuild BEFORE serverless-plugin-warmup, it fails to package the serverless_sdk folder and the s_warmupPluginDefault.js file. If I move serverless-esbuild after serverless-plugin-warmup, however, it packages everything properly.

For example. This does not work:

plugins:
  - serverless-esbuild
  - serverless-plugin-warmup

However, this does work:

plugins:
  - serverless-plugin-warmup
  - serverless-esbuild

I assume it has something to do with lifecycle hooks competing between esbuild and warmup, but I don’t know for sure.

r-token on Feb 8, 2023

@juanjoDiaz Thanks for the prompt response. My mistake on the version number, that was a mistype on my end! 7.1.0 is the one I am on.

So I actually just got everything working on my end using what minu2020 had pasted above (adding in the package options to my config) on Feb 1, 2022. I’m still not entirely sure what the issue was, but everything seems to be alright now.

The warmup config that I am now using successfully is:

warmup:
  default:
    prewarm: true
    package:
      individually: true
      patterns:
        - "!../**"
        - "!../../**"
        - ./serverless_sdk/*
        - ./s_warmUpPluginDefault.js

brendenkrochko on Jul 4, 2022

@juanjoDiaz Its working fine for me after adding the following under custom.warmup.default

      package:
        individually: true
        patterns:
          - '!../**'
          - '!../../**'
          - ./wsgi_handler.py
          - ./serverless_wsgi.py
          - ./serverless_sdk/*
          - ./s_warmUpPluginDefault.js
          - ./s_api.py

Minu2020 on Feb 3, 2022