Error: Cannot find module 'unit-http/loader'

[stacy-rendall]

I am receiving this error trying to use Unit with Node.js

To repro I've tested completely clean from scratch in a fresh Debian live image (debian-live-12.5.0-amd64-lxqt.iso) and still get the error. Steps:

• Install Unit: https://unit.nginx.org/installation/#debian-12 along with unit-dev package
• Install Node 20 (as root) via: https://github.com/nodesource/distributions?tab=readme-ov-file#using-debian-as-root-nodejs-20
• Follow instructions (i.e. creating app.js etc.): https://unit.nginx.org/howto/express/

On attempting to put the config I get the following response:

{
    "error": "Failed to apply new configuration."
}

And the log shows:

2024/06/12 16:37:58 [info] 5052#5052 "express" prototype started
2024/06/12 16:37:58 [info] 5053#5053 "express" application started
node:internal/modules/cjs/loader:1148
  throw err;
  ^

Error: Cannot find module 'unit-http/loader'
Require stack:
- internal/preload
    at Module._resolveFilename (node:internal/modules/cjs/loader:1145:15)
    at Module._load (node:internal/modules/cjs/loader:986:27)
    at internalRequire (node:internal/modules/cjs/loader:176:19)
    at Module._preloadModules (node:internal/modules/cjs/loader:1563:5)
    at loadPreloadModules (node:internal/process/pre_execution:730:5)
    at setupUserModules (node:internal/process/pre_execution:206:5)
    at prepareExecution (node:internal/process/pre_execution:159:5)
    at prepareMainThreadExecution (node:internal/process/pre_execution:54:10)
    at node:internal/main/run_main_module:11:19 {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ 'internal/preload' ]
}

Node.js v20.14.0
2024/06/12 16:37:58 [notice] 5052#5052 app process 5053 exited with code 1
2024/06/12 16:37:58 [warn] 1199#1199 failed to start application "express"
2024/06/12 16:37:58 [alert] 1199#1199 failed to apply new conf
2024/06/12 16:37:58 [notice] 1195#1195 process 5052 exited with code 0

[dbit-xia]

Attempt to execute the npm command or add a dependency

npm install unit-http 

[stacy-rendall]

That executes successfully:

user@debian:~/repos/expressunit$ npm install unit-http 

changed 1 package, and audited 66 packages in 985ms

12 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities

package.json

{
  "dependencies": {
    "express": "^4.19.2",
    "unit-http": "^1.32.1"
  },
  "name": "expressunit",
  "version": "1.0.0",
  "main": "app.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "description": ""
}

I attempted a few different combinations on my Debian 12 OS (not the live OS as above, which ws just for a clean repro), all of which still give the same error as shown in my first post, when applying the config:

1. without linking at all:
   1. take back app ownership as user
   2. remove global unit-http install: sudo npm -g uninstall unit-http
   3. rm -rf node_modules package-lock.json
   4. npm install express unit-http
   5. chown app unit:unit
   6. apply config
2. global install, local install, no link:
   1. redo sudo npm install -g --unsafe-perm unit-http
   2. take back app ownership as user
   3. rm -rf node_modules package-lock.json
   4. npm install express unit-http
   5. chown app unit:unit
   6. apply config
3. global install, local install, then link:
   1. with unit-http still available as global dependency
   2. take back app ownership as user
   3. rm -rf node_modules package-lock.json
   4. npm install express unit-http
   5. sudo npm link unit-http
   6. chown app unit:unit
   7. apply config
4. global install, link, then local install:
   1. with unit-http still available as global dependency
   2. take back app ownership as user
   3. sudo npm link unit-http
   4. npm install express unit-http
   5. chown app unit:unit
   6. apply config

[dbit-xia]

Check whether the working_directory configured in the unit is the application root directory? Or enter the container and execute the command node -e 'require('unit-http/loader')'