firebase emulators:start always ignores `.env` file and throws “Attempted to write param-defined key” error

[pan93412]

[REQUIRED] Environment info

firebase-tools: 11.16.0

Platform: macOS Ventura 13.0

[REQUIRED] Test case

https://github.com/pan93412/firebase-question-221105/tree/373cce9e7093f707198cfa0ff2fbba561c6b167c

[REQUIRED] Steps to reproduce

1. Create a project that reads environment variables with firebase-functions/params, see “Test case.”
2. Remove all the .env* files – ensure the following .env file is generated by firebase-tools.
3. Run pnpm serve to build from TypeScript src and run firebase emulators:start
4. firebase-tools prompts to type my DISCORD_TOKEN and GUILD – it is expected.
5. Then, it generates a .env-[project name] file, and the function starts correctly.
6. ⌘C, and re-run pnpm serve.
7. It requires me to type the variables that has inputted in 4. and saved in 5. – it is unexpected.
8. After typing the same value typed in 4. and press Enter, it throws the following message:

   Failed to load function definition from source: FirebaseError: Attempted to write param-defined key DISCORD_TOKEN to .env files, but it was already defined.
   

9. After throwing, I can not see any functions starts, resulting me to remove the generated .env to let it work again.

The screencast:

firebase-tools-unexpected-behavior-221106.mp4

[REQUIRED] Expected behavior

• It should read our .env file, and not prompt for typing again.
• “.env write exception” should not block the whole start process.

[REQUIRED] Actual behavior

> functions@ serve /Volumes/Dev/Projects/ciscc-v3-backend/functions
> npm run build && firebase emulators:start --only functions "--debug"


> build
> tsc

[2022-11-05T16:28:45.339Z] > command requires scopes: ["email","openid","https://www.googleapis.com/auth/cloudplatformprojects.readonly","https://www.googleapis.com/auth/firebase","https://www.googleapis.com/auth/cloud-platform"]
[2022-11-05T16:28:45.339Z] > authorizing via signed-in user (pan93412@gmail.com)
i  emulators: Starting emulators: functions {"metadata":{"emulator":{"name":"hub"},"message":"Starting emulators: functions"}}
[2022-11-05T16:28:45.584Z] [logging] Logging Emulator only supports listening on one address (127.0.0.1). Not listening on ::1
[2022-11-05T16:28:45.584Z] assigned listening specs for emulators {"user":{"hub":[{"address":"127.0.0.1","family":"IPv4","port":4400},{"address":"::1","family":"IPv6","port":4400}],"ui":[{"address":"127.0.0.1","family":"IPv4","port":4000},{"address":"::1","family":"IPv6","port":4000}],"logging":[{"address":"127.0.0.1","family":"IPv4","port":4500}]},"metadata":{"message":"assigned listening specs for emulators"}}
[2022-11-05T16:28:45.591Z] [hub] writing locator at /var/folders/cn/c_n1ss3x7rx78k6mpw9t6bsm0000gn/T/hub-ciscc-18220.json
[2022-11-05T16:28:45.768Z] [functions] Functions Emulator only supports listening on one address (127.0.0.1). Not listening on ::1
[2022-11-05T16:28:45.768Z] [eventarc] Eventarc Emulator only supports listening on one address (127.0.0.1). Not listening on ::1
[2022-11-05T16:28:45.768Z] late-assigned ports for functions and eventarc emulators {"user":{"hub":[{"address":"127.0.0.1","family":"IPv4","port":4400},{"address":"::1","family":"IPv6","port":4400}],"ui":[{"address":"127.0.0.1","family":"IPv4","port":4000},{"address":"::1","family":"IPv6","port":4000}],"logging":[{"address":"127.0.0.1","family":"IPv4","port":4500}],"functions":[{"address":"127.0.0.1","family":"IPv4","port":5001}],"eventarc":[{"address":"127.0.0.1","family":"IPv4","port":9299}]},"metadata":{"message":"late-assigned ports for functions and eventarc emulators"}}
⚠  functions: The following emulators are not running, calls to these services from the Functions emulator will affect production: auth, firestore, database, hosting, pubsub, storage {"metadata":{"emulator":{"name":"functions"},"message":"The following emulators are not running, calls to these services from the Functions emulator will affect production: \u001b[1mauth, firestore, database, hosting, pubsub, storage\u001b[22m"}}
✔  functions: Using node@16 from host. {"metadata":{"emulator":{"name":"functions"},"message":"Using node@16 from host."}}
[2022-11-05T16:28:45.775Z] defaultcredentials: writing to file /Users/pan93412/.config/firebase/pan93412_gmail_com_application_default_credentials.json
[2022-11-05T16:28:45.779Z] Setting GAC to /Users/pan93412/.config/firebase/pan93412_gmail_com_application_default_credentials.json {"metadata":{"emulator":{"name":"functions"},"message":"Setting GAC to /Users/pan93412/.config/firebase/pan93412_gmail_com_application_default_credentials.json"}}
[2022-11-05T16:28:45.780Z] >>> [apiv2][query] GET https://firebase.googleapis.com/v1beta1/projects/ciscc-18220/adminSdkConfig [none]
[2022-11-05T16:28:46.214Z] <<< [apiv2][status] GET https://firebase.googleapis.com/v1beta1/projects/ciscc-18220/adminSdkConfig 200
[2022-11-05T16:28:46.214Z] <<< [apiv2][body] GET https://firebase.googleapis.com/v1beta1/projects/ciscc-18220/adminSdkConfig {"projectId":"ciscc-18220","storageBucket":"ciscc-18220.appspot.com"}
[2022-11-05T16:28:46.235Z] Ignoring unsupported arg: auto_download {"metadata":{"emulator":{"name":"ui"},"message":"Ignoring unsupported arg: auto_download"}}
[2022-11-05T16:28:46.235Z] Ignoring unsupported arg: port {"metadata":{"emulator":{"name":"ui"},"message":"Ignoring unsupported arg: port"}}
[2022-11-05T16:28:46.235Z] Starting Emulator UI with command {"binary":"node","args":["/Users/pan93412/.cache/firebase/emulators/ui-v1.11.1/server/server.js"],"optionalArgs":[],"joinArgs":false} {"metadata":{"emulator":{"name":"ui"},"message":"Starting Emulator UI with command {\"binary\":\"node\",\"args\":[\"/Users/pan93412/.cache/firebase/emulators/ui-v1.11.1/server/server.js\"],\"optionalArgs\":[],\"joinArgs\":false}"}}
i  ui: Emulator UI logging to ui-debug.log {"metadata":{"emulator":{"name":"ui"},"message":"Emulator UI logging to \u001b[1mui-debug.log\u001b[22m"}}
[2022-11-05T16:28:46.339Z] Web / API server started at 127.0.0.1:4000
 {"metadata":{"emulator":{"name":"ui"},"message":"Web / API server started at 127.0.0.1:4000\n"}}
[2022-11-05T16:28:46.340Z] Web / API server started at ::1:4000
 {"metadata":{"emulator":{"name":"ui"},"message":"Web / API server started at ::1:4000\n"}}
i  functions: Watching "/Volumes/Dev/Projects/ciscc-v3-backend/functions" for Cloud Functions... {"metadata":{"emulator":{"name":"functions"},"message":"Watching \"/Volumes/Dev/Projects/ciscc-v3-backend/functions\" for Cloud Functions..."}}
[2022-11-05T16:28:46.502Z] Validating nodejs source
[2022-11-05T16:28:50.025Z] > [functions] package.json contents: {
  "name": "functions",
  "scripts": {
    "lint": "eslint --ext .js,.ts .",
    "build": "tsc",
    "build:watch": "tsc --watch",
    "serve": "npm run build && firebase emulators:start --only functions",
    "shell": "npm run build && firebase functions:shell",
    "start": "npm run shell",
    "deploy": "firebase deploy --only functions",
    "logs": "firebase functions:log"
  },
  "type": "module",
  "engines": {
    "node": "16"
  },
  "main": "lib/index.js",
  "dependencies": {
    "@firebase/app-types": "^0.8.1",
    "discord-api-types": "^0.37.16",
    "discord.js": "^14.6.0",
    "firebase-admin": "^11.2.0",
    "firebase-functions": "^4.0.2",
    "nominal-types": "^0.1.2"
  },
  "devDependencies": {
    "@typescript-eslint/eslint-plugin": "^5.12.0",
    "@typescript-eslint/parser": "^5.12.0",
    "eslint": "^8.9.0",
    "eslint-config-google": "^0.14.0",
    "eslint-config-prettier": "^8.5.0",
    "eslint-plugin-import": "^2.25.4",
    "firebase-functions-test": "^3.0.0",
    "firebase-tools": "^11.16.0",
    "jest": "^29.2.2",
    "typescript": "5.0.0-dev.20221103"
  },
  "private": true
}
[2022-11-05T16:28:50.026Z] Building nodejs source
[2022-11-05T16:28:50.026Z] Analyzing nodejs backend spec
[2022-11-05T16:28:50.028Z] Could not find functions.yaml. Must use http discovery
[2022-11-05T16:28:50.194Z] Serving at port 9005

[2022-11-05T16:28:50.517Z] Got response from /__/functions.yaml {"endpoints":{"addnumbers":{"availableMemoryMb":null,"timeoutSeconds":null,"minInstances":null,"maxInstances":null,"ingressSettings":null,"concurrency":null,"serviceAccountEmail":null,"vpc":null,"platform":"gcfv2","labels":{},"callableTrigger":{},"entryPoint":"addnumbers"},"getstickers":{"availableMemoryMb":null,"timeoutSeconds":null,"minInstances":null,"maxInstances":null,"ingressSettings":null,"concurrency":null,"serviceAccountEmail":null,"vpc":null,"platform":"gcfv2","labels":{},"httpsTrigger":{},"entryPoint":"getstickers"}},"specVersion":"v1alpha1","requiredAPIs":[],"params":[{"name":"DISCORD_TOKEN","type":"string"},{"name":"GUILD","type":"string"}]}
[2022-11-05T16:28:50.524Z] shutdown requested via /__/quitquitquit

? Enter a string value for DISCORD_TOKEN: 
? Enter a string value for GUILD: 
i  functions: Loaded environment variables from .env.ciscc-18220. 
i  functions: Loaded environment variables from .env.ciscc-18220. 
⬢  functions: Failed to load function definition from source: FirebaseError: Attempted to write param-defined key DISCORD_TOKEN to .env files, but it was already defined. {"metadata":{"emulator":{"name":"functions"},"message":"Failed to load function definition from source: FirebaseError: Attempted to write param-defined key DISCORD_TOKEN to .env files, but it was already defined."}}

┌─────────────────────────────────────────────────────────────┐
│ ✔  All emulators ready! It is now safe to connect your app. │
│ i  View Emulator UI at http://127.0.0.1:4000/               │
└─────────────────────────────────────────────────────────────┘

┌───────────┬────────────────┬─────────────────────────────────┐
│ Emulator  │ Host:Port      │ View in Emulator UI             │
├───────────┼────────────────┼─────────────────────────────────┤
│ Functions │ 127.0.0.1:5001 │ http://127.0.0.1:4000/functions │
└───────────┴────────────────┴─────────────────────────────────┘
  Emulator Hub running at 127.0.0.1:4400
  Other reserved ports: 4500

Issues? Report them at https://github.com/firebase/firebase-tools/issues and attach the *-debug.log files.
 
^C[2022-11-05T16:28:59.201Z] Received signal SIGINT (Ctrl-C) 1
 
i  emulators: Received SIGINT (Ctrl-C) for the first time. Starting a clean shutdown. 
i  emulators: Please wait for a clean shutdown or send the SIGINT (Ctrl-C) signal again to stop right now. 
i  emulators: Shutting down emulators. {"metadata":{"emulator":{"name":"hub"},"message":"Shutting down emulators."}}
i  ui: Stopping Emulator UI {"metadata":{"emulator":{"name":"ui"},"message":"Stopping Emulator UI"}}
⚠  Emulator UI has exited upon receiving signal: SIGINT 
i  functions: Stopping Functions Emulator {"metadata":{"emulator":{"name":"functions"},"message":"Stopping Functions Emulator"}}
i  eventarc: Stopping Eventarc Emulator {"metadata":{"emulator":{"name":"eventarc"},"message":"Stopping Eventarc Emulator"}}
i  hub: Stopping emulator hub {"metadata":{"emulator":{"name":"hub"},"message":"Stopping emulator hub"}}
i  logging: Stopping Logging Emulator {"metadata":{"emulator":{"name":"logging"},"message":"Stopping Logging Emulator"}}

keywords: Attempted to write param-defined key, Failed to load function definition from source, environment variable, .env, params

[pan93412]

For people who want to workaround with this: Disable functionsparams experiment:

firebase experiments:disable functionsparams

Or downgrade firebase-tools to 11.15.0:

pnpm add -D firebase-tools@=11.15.0

---

@inlined After bisecting, I found that this issue was introduced in commit 87e8f0c, which switches functionsparams¹ to true.

After I changed the functionsparams to false, it worked immediately:

Not really sure how to fix it as I'm not familiar to functionsparams. Could you help me take a look with this? Thanks!

Footnotes

1. The source code of functionsparams feature on the latest master commit:
   https://github.com/firebase/firebase-tools/blob/98e23eded74e49f58d48be0417dc66bd85ea6e11/src/deploy/functions/build.ts#L284-L301 ↩

[colerogers]

Hey @Berlioz I think you know this codebase a bit better than me, do you mind taking a look at this?

[juane1000]

Experiencing this exact same issue. Migrated to .env variable from functions.config method. When starting emulators it prompts for default values in the terminal even when a default is in the code.

[juane1000]

@pan93412 your two workarounds result in this error being thrown in the startup process

"functions: Failed to load function definition from source: FirebaseError: CEL identity expression '{{ params.MIN_INSTANCES }}' was not resolvable to a param"

Did you encounter this? Before trying your workarounds I did manually enter a value when prompted in the terminal but it would at least startup correctly. So I'm not sure what the cause is here.

[pan93412]

@pan93412 your two workarounds result in this error being thrown in the startup process

"functions: Failed to load function definition from source: FirebaseError: CEL identity expression '{{ params.MIN_INSTANCES }}' was not resolvable to a param"

Did you encounter this? Before trying your workarounds I did manually enter a value when prompted in the terminal but it would at least startup correctly. So I'm not sure what the cause is here.

I never encountered it, sorry.

[RogerBetter]

Experiencing this exact same issue. Migrated to .env variable from functions.config method. When starting emulators it prompts for default values in the terminal even when a default is in the code.

same here

[siarheidudko]

same problem