Firebase store Emulator keeps saying "The service is currently unavailable."

Question

I am developing a flutter app. I'm trying to use the Firebase emulator as a backend during development.

I configured the emulator, and when I used the “firebase emulators:start” command, I confirmed that the following response came out.

Emulator Host:Port View in Emulator UI
Authentication 0.0.0.0:9099 | http://127.0.0.1:4000/auth
Functions 0.0.0.0:5001 | http://127.0.0.1:4000/functions
Firestore 0.0.0.0:8080 | http://127.0.0.1:4000/firestore
Storage 0.0.0.0:9199 | http://127.0.0.1:4000/storage

So, I coded the part that initializes the Firebase settings as follows.

 Future initializeApp() async {
    await Firebase.initializeApp(
      options: DefaultFirebaseOptions.currentPlatform,
    );
    FirebaseAuth.instance.useAuthEmulator("0.0.0.0", 9099);
    FirebaseFunctions.instance.useFunctionsEmulator("0.0.0.0", 5001);
    FirebaseStorage.instance.bucket = 'default-bucket';
    FirebaseStorage.instance.useStorageEmulator("0.0.0.0", 9199);
    FirebaseFirestore.instance.useFirestoreEmulator("0.0.0.0", 8080);
    FirebaseFirestore.instance.settings = const Settings(
      host: "0.0.0.0",
      persistenceEnabled: false,
      sslEnabled: false,
    );
  }

My firebase.json is below

{
  "functions": {
    "predeploy": "npm --prefix \"$RESOURCE_DIR\" run build",
    "source": "functions"
  },
  "emulators": {
    "auth": {
      "host": "0.0.0.0",
      "port": 9099
    },
    "functions": {
      "host": "0.0.0.0",
      "port": 5001
    },
    "firestore": {
      "host": "0.0.0.0",
      "port": 8080
    },
    "storage": {
      "host": "0.0.0.0",
      "port": 9199
    },
    "ui": {
      "enabled": true
    }
  },
  "firestore": {
    "rules": "firestore.rules",
    "indexes": "firestore.indexes.json"
  },
  "storage": {
    "rules": "storage.rules"
  }
}

But when I try to use firestore, it says "Unhandled Exception: [cloud_firestore/unavailable] The service is currently unavailable. This is a most likely a transient condition and may be corrected by retrying with a backoff.".

I think I've done all the settings. I can't figure out which part is wrong. hope for help

Below is the firestore-debug.log file.

Nov 25, 2022 9:34:42 AM com.google.cloud.datastore.emulator.firestore.websocket.WebSocketServer start
INFO: Started WebSocket server on ws://0.0.0.0:9150
API endpoint: http://0.0.0.0:8080
If you are using a library that supports the FIRESTORE_EMULATOR_HOST environment variable, run:

   export FIRESTORE_EMULATOR_HOST=0.0.0.0:8080

Dev App Server is now running.

Nov 25, 2022 9:34:44 AM io.gapi.emulators.netty.HttpVersionRoutingHandler channelRead
INFO: Detected non-HTTP/2 connection.
Nov 25, 2022 9:34:45 AM io.gapi.emulators.netty.HttpVersionRoutingHandler channelRead
INFO: Detected non-HTTP/2 connection.
Nov 25, 2022 9:34:48 AM io.gapi.emulators.netty.HttpVersionRoutingHandler channelRead
INFO: Detected non-HTTP/2 connection.
Nov 25, 2022 9:34:48 AM io.gapi.emulators.netty.HttpVersionRoutingHandler channelRead
INFO: Detected HTTP/2 connection.
Nov 25, 2022 9:35:46 AM com.google.cloud.datastore.emulator.firestore.websocket.WebSocketChannelHandler initChannel
INFO: Connected to new websocket client
Nov 25, 2022 9:35:46 AM io.gapi.emulators.netty.HttpVersionRoutingHandler channelRead
INFO: Detected non-HTTP/2 connection.
Nov 25, 2022 9:36:46 AM io.gapi.emulators.netty.HttpVersionRoutingHandler channelRead
INFO: Detected non-HTTP/2 connection.
*** shutting down gRPC server since JVM is shutting down
*** server shut down

Strange thing is, the Auth Emulator works just fine.

Answer 1

I found the answer. I had to change the order of the code.

Future initializeApp() async {
    await Firebase.initializeApp(
      options: DefaultFirebaseOptions.currentPlatform,
    );
    FirebaseAuth.instance.useAuthEmulator("0.0.0.0", 9099);
    FirebaseFunctions.instance.useFunctionsEmulator("0.0.0.0", 5001);
    FirebaseStorage.instance.bucket = 'default-bucket';
    FirebaseStorage.instance.useStorageEmulator("0.0.0.0", 9199);
    FirebaseFirestore.instance.useFirestoreEmulator("0.0.0.0", 8080);
    FirebaseFirestore.instance.settings = const Settings(
      host: "0.0.0.0",
      persistenceEnabled: false,
      sslEnabled: false,
    );
  }

Changing this code to the following works:

Future initializeApp() async {
    await Firebase.initializeApp(
      options: DefaultFirebaseOptions.currentPlatform,
    );
    await FirebaseAuth.instance.useAuthEmulator("0.0.0.0", 9099);
    FirebaseFunctions.instance.useFunctionsEmulator("0.0.0.0", 5001);
    FirebaseStorage.instance.bucket = 'default-bucket';
    FirebaseFirestore.instance.settings = const Settings(
      host: "0.0.0.0",
      persistenceEnabled: false,
      sslEnabled: false,
    );
    FirebaseFirestore.instance.useFirestoreEmulator("0.0.0.0", 8080);
    await FirebaseStorage.instance.useStorageEmulator("0.0.0.0", 9199);
  }

I think, I need to set “FirebaseFirestore.instance.settings ” first and then "FirebaseFirestore.instance.useFirestoreEmulator"