How to connect to Cloud Firestore DB with .net core?

Question

So far all the examples of using Google Cloud Firestore with .net show that you connect to your Firestore db by using this command:

FirestoreDb db = FirestoreDb.Create(projectId);

But is this skipping the step of authentication? I can't seem to find an example of wiring it up to use a Google service account. I'm guessing you need to connect using the service account's private_key/private_key_id/client_email?

Answer 1

You can also use the credentials stored in a json file:

    GoogleCredential cred = GoogleCredential.FromFile("credentials.json");
    Channel channel = new Channel(FirestoreClient.DefaultEndpoint.Host,
                  FirestoreClient.DefaultEndpoint.Port,
                  cred.ToChannelCredentials());
    FirestoreClient client = FirestoreClient.Create(channel);
    FirestoreDb db = FirestoreDb.Create("my-project", client);

Answer 2

I could not compile @Michael Bleterman's code, however the following worked for me:

using Google.Cloud.Firestore;
using Google.Cloud.Firestore.V1;


var jsonString = File.ReadAllText(_keyFilepath);
var builder = new FirestoreClientBuilder {JsonCredentials = jsonString};
FirestoreDb db = FirestoreDb.Create(_projectId, builder.Build());

Packages I use:

<PackageReference Include="Google.Cloud.Firestore" Version="2.0.0-beta02" />
<PackageReference Include="Google.Cloud.Storage.V1" Version="2.5.0" />

Answer 3

But is this skipping the step of authentication?

No. It will use the default application credentials. If you're running on Google Cloud Platform (AppEngine, GCE or GKE), they will just be the default service account credentials for the instance. Otherwise, you should set the GOOGLE_APPLICATION_CREDENTIALS environment variable to refer to a service account credential file.

From the home page of the user guide you referred to:

When running on Google Cloud Platform, no action needs to be taken to authenticate.

Otherwise, the simplest way of authenticating your API calls is to download a service account JSON file then set the GOOGLE_APPLICATION_CREDENTIALS environment variable to refer to it. The credentials will automatically be used to authenticate. See the Getting Started With Authentication guide for more details.

It's somewhat more awkward to use non-default credentials; this recent issue gives an example.

Answer 4

This worked for me.

https://pieterdlinde.medium.com/netcore-and-cloud-firestore-94628943eb3c

string filepath = "/Users/user/Downloads/user-a4166-firebase-adminsdk-ivk8q-d072fdf334.json";
Environment.SetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS", filepath);
fireStoreDb = FirestoreDb.Create("user-a4166");

Answer 5

The simplest way:

Get service account json file and hardcode values into a class:

    public class FirebaseSettings
    {
        [JsonPropertyName("project_id")]
        public string ProjectId => "that-rug-really-tied-the-room-together-72daa";
    
        [JsonPropertyName("private_key_id")]
        public string PrivateKeyId => "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    
        // ... and so on
    }

Add it Startup.cs

var firebaseJson = JsonSerializer.Serialize(new FirebaseSettings());

services.AddSingleton(_ => new FirestoreProvider(
    new FirestoreDbBuilder 
    { 
        ProjectId = firebaseSettings.ProjectId, 
        JsonCredentials = firebaseJson // <-- service account json file
    }.Build()
));

Add wrapper FirebaseProvider

public class FirestoreProvider
{
    private readonly FirestoreDb _fireStoreDb = null!;

    public FirestoreProvider(FirestoreDb fireStoreDb)
    {
        _fireStoreDb = fireStoreDb;
    }

    // ... your methods here

}

Here is a full example of a generic provider.

https://dev.to/kedzior_io/simple.net-core-and-cloud-firestore-setup-1pf9