FR: add ability to communicate with Auth Emulator

[branks]

On the emulator documentation it states the the Node SDK can connect to the Firebase Authentication Emulator by using an environment variable - https://firebase.google.com/docs/emulator-suite/connect_auth

export FIREBASE_AUTH_EMULATOR_HOST="localhost:9099"

It would be great if this could also be supported in the Java SDK

[dv-bv]

Any timelines on this one? Any way we could help getting this through the door?

[yuchenshi]

@dv-bv Sure! We welcome Pull Requests that add support for the environment variable to the Java Admin SDK.

Just keep in mind that we're still having some important discussions on verifyIdToken so that may not land soon. We'd be happy to review PRs for supporting all other methods. (And by the way, while we do not commit to timelines, your can definitely help to get this through the door.

[7agustibm]

Hi! I start this PR: #510

[7agustibm]

Hi! When will the new version be available with this feature?

[dmitri-gb]

Just keep in mind that we're still having some important discussions on verifyIdToken so that may not land soon.

@yuchenshi, are there any updates on those discussions about verifyIdToken? I noticed that the Node Admin SDK was recently changed to always accept unsigned tokens when the emulator is in use. Will the Java SDK follow suit?

[yuchenshi]

@dmitri-gb As you've observed, we've reached some conclusions regarding verifyIdToken and we're now working on implementing consistent support across Admin SDKs. Namely, verifyIdToken will accept unsigned tokens if the environment variable is set and the emulator is running.

While we're unable to provide ETAs, please rest assured we're building on top of @7agustibm's amazing work for network communications and we'll release once we have ID token support as well.

[at15]

A snippet for connecting to auth emulator and import user https://firebase.google.com/docs/auth/admin/import-users#java

package foo;

import java.util.ArrayList;
import java.util.List;

import com.google.firebase.FirebaseApp;
import com.google.firebase.FirebaseOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseAuthException;
import com.google.firebase.auth.ImportUserRecord;
import com.google.firebase.auth.UserImportOptions;
import com.google.firebase.auth.hash.HmacSha256;
import com.google.firebase.internal.EmulatorCredentials;
import com.google.firebase.internal.FirebaseProcessEnvironment;

import org.junit.jupiter.api.Test;

public class ImportUserTest {
    @Test
    public void testImportLocal() throws FirebaseAuthException {
        // Create FirestoreAuth connecting to local emulator
        // https://github.com/firebase/firebase-admin-java/issues/493
        FirebaseProcessEnvironment.setenv("FIREBASE_AUTH_EMULATOR_HOST", "localhost:9099");
        FirebaseOptions options = FirebaseOptions.builder()
                .setProjectId("foo-abcd")
                .setCredentials(new EmulatorCredentials())
                .build();
        FirebaseApp.initializeApp(options);
        FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();

        List<ImportUserRecord> users = new ArrayList<>();
        users.add(ImportUserRecord.builder()
                .setUid("uid1")
                .setEmail("[email protected]")
                .setPasswordHash("passwordHash1".getBytes())
                .setPasswordSalt("salt1".getBytes())
                .build());
        UserImportOptions userImportOptions = UserImportOptions.withHash(
                HmacSha256.builder()
                        .setKey("secretKey".getBytes())
                        .build());
        firebaseAuth.importUsers(users, userImportOptions);
    }
}