使用 Admin SDK,您可以使用完整的管理權限或更細粒度的有限權限來讀取和寫入即時資料庫資料。在本文檔中,我們將指導您將 Firebase Admin SDK 新增至您的專案中以存取 Firebase 即時資料庫。
管理 SDK 設定
要開始在伺服器上使用 Firebase 即時資料庫,您首先需要使用您選擇的語言設定 Firebase Admin SDK 。
管理員SDK認證
在使用 Firebase Admin SDK 從伺服器存取 Firebase 即時資料庫之前,您必須使用 Firebase 對伺服器進行驗證。當您對伺服器進行身份驗證時,您不是像在客戶端應用程式中那樣使用使用者帳戶的憑證登錄,而是使用向 Firebase 標識您的伺服器的服務帳戶進行身份驗證。
使用 Firebase Admin SDK 進行身份驗證時,您可以獲得兩種不同等級的存取權限:
Firebase 管理 SDK 身份驗證存取級別 | |
---|---|
管理權限 | 完成專案即時資料庫的讀寫存取。請謹慎完成管理任務,例如需要不受限制地存取專案資源的資料遷移或重組。 |
有限特權 | 存取專案的即時資料庫,僅限於您的伺服器所需的資源。使用此等級可以完成具有明確定義的存取要求的管理任務。例如,當執行在整個資料庫中讀取資料的總計作業時,您可以透過設定唯讀安全性規則,然後使用受該規則限制的權限初始化 Admin SDK 來防止意外寫入。 |
使用管理員權限進行身份驗證
當您使用 Firebase 專案上具有編輯者角色的服務帳戶的憑證初始化 Firebase Admin SDK 時,該執行個體對您的專案的即時資料庫具有完整的讀寫存取權。
爪哇
// Fetch the service account key JSON file contents FileInputStream serviceAccount = new FileInputStream("path/to/serviceAccount.json"); // Initialize the app with a service account, granting admin privileges FirebaseOptions options = FirebaseOptions.builder() .setCredentials(GoogleCredentials.fromStream(serviceAccount)) // The database URL depends on the location of the database .setDatabaseUrl("https://DATABASE_NAME.firebaseio.com") .build(); FirebaseApp.initializeApp(options); // As an admin, the app has access to read and write all data, regardless of Security Rules DatabaseReference ref = FirebaseDatabase.getInstance() .getReference("restricted_access/secret_document"); ref.addListenerForSingleValueEvent(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { Object document = dataSnapshot.getValue(); System.out.println(document); } @Override public void onCancelled(DatabaseError error) { } });
Node.js
var admin = require("firebase-admin"); // Fetch the service account key JSON file contents var serviceAccount = require("path/to/serviceAccountKey.json"); // Initialize the app with a service account, granting admin privileges admin.initializeApp({ credential: admin.credential.cert(serviceAccount), // The database URL depends on the location of the database databaseURL: "https://DATABASE_NAME.firebaseio.com" }); // As an admin, the app has access to read and write all data, regardless of Security Rules var db = admin.database(); var ref = db.ref("restricted_access/secret_document"); ref.once("value", function(snapshot) { console.log(snapshot.val()); });
Python
import firebase_admin from firebase_admin import credentials from firebase_admin import db # Fetch the service account key JSON file contents cred = credentials.Certificate('path/to/serviceAccountKey.json') # Initialize the app with a service account, granting admin privileges firebase_admin.initialize_app(cred, { 'databaseURL': 'https://databaseName.firebaseio.com' }) # As an admin, the app has access to read and write all data, regradless of Security Rules ref = db.reference('restricted_access/secret_document') print(ref.get())
去
ctx := context.Background() conf := &firebase.Config{ DatabaseURL: "https://databaseName.firebaseio.com", } // Fetch the service account key JSON file contents opt := option.WithCredentialsFile("path/to/serviceAccountKey.json") // Initialize the app with a service account, granting admin privileges app, err := firebase.NewApp(ctx, conf, opt) if err != nil { log.Fatalln("Error initializing app:", err) } client, err := app.Database(ctx) if err != nil { log.Fatalln("Error initializing database client:", err) } // As an admin, the app has access to read and write all data, regradless of Security Rules ref := client.NewRef("restricted_access/secret_document") var data map[string]interface{} if err := ref.Get(ctx, &data); err != nil { log.Fatalln("Error reading from database:", err) } fmt.Println(data)
使用有限權限進行身份驗證
作為最佳實踐,服務應該只能存取它需要的資源。若要對 Firebase 應用程式實例可以存取的資源進行更細微的控制,請在安全性規則中使用唯一識別碼來表示您的服務。然後設定適當的規則,授予您的服務對其所需資源的存取權限。例如:
{ "rules": { "public_resource": { ".read": true, ".write": true }, "some_resource": { ".read": "auth.uid === 'my-service-worker'", ".write": false }, "another_resource": { ".read": "auth.uid === 'my-service-worker'", ".write": "auth.uid === 'my-service-worker'" } } }
然後,在您的伺服器上,當您初始化 Firebase 應用程式時,使用databaseAuthVariableOverride
選項來覆寫資料庫規則所使用的auth
物件。在此自訂auth
物件中,將uid
欄位設定為您在安全性規則中用於表示服務的識別碼。
爪哇
// Fetch the service account key JSON file contents FileInputStream serviceAccount = new FileInputStream("path/to/serviceAccountCredentials.json"); // Initialize the app with a custom auth variable, limiting the server's access Map<String, Object> auth = new HashMap<String, Object>(); auth.put("uid", "my-service-worker"); FirebaseOptions options = new FirebaseOptions.Builder() .setCredential(FirebaseCredentials.fromCertificate(serviceAccount)) // The database URL depends on the location of the database .setDatabaseUrl("https://DATABASE_NAME.firebaseio.com") .setDatabaseAuthVariableOverride(auth) .build(); FirebaseApp.initializeApp(options); // The app only has access as defined in the Security Rules DatabaseReference ref = FirebaseDatabase .getInstance() .getReference("/some_resource"); ref.addListenerForSingleValueEvent(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { String res = dataSnapshot.getValue(); System.out.println(res); } });
Node.js
var admin = require("firebase-admin"); // Fetch the service account key JSON file contents var serviceAccount = require("path/to/serviceAccountKey.json"); // Initialize the app with a custom auth variable, limiting the server's access admin.initializeApp({ credential: admin.credential.cert(serviceAccount), // The database URL depends on the location of the database databaseURL: "https://DATABASE_NAME.firebaseio.com", databaseAuthVariableOverride: { uid: "my-service-worker" } }); // The app only has access as defined in the Security Rules var db = admin.database(); var ref = db.ref("/some_resource"); ref.once("value", function(snapshot) { console.log(snapshot.val()); });
Python
import firebase_admin from firebase_admin import credentials from firebase_admin import db # Fetch the service account key JSON file contents cred = credentials.Certificate('path/to/serviceAccountKey.json') # Initialize the app with a custom auth variable, limiting the server's access firebase_admin.initialize_app(cred, { 'databaseURL': 'https://databaseName.firebaseio.com', 'databaseAuthVariableOverride': { 'uid': 'my-service-worker' } }) # The app only has access as defined in the Security Rules ref = db.reference('/some_resource') print(ref.get())
去
ctx := context.Background() // Initialize the app with a custom auth variable, limiting the server's access ao := map[string]interface{}{"uid": "my-service-worker"} conf := &firebase.Config{ DatabaseURL: "https://databaseName.firebaseio.com", AuthOverride: &ao, } // Fetch the service account key JSON file contents opt := option.WithCredentialsFile("path/to/serviceAccountKey.json") app, err := firebase.NewApp(ctx, conf, opt) if err != nil { log.Fatalln("Error initializing app:", err) } client, err := app.Database(ctx) if err != nil { log.Fatalln("Error initializing database client:", err) } // The app only has access as defined in the Security Rules ref := client.NewRef("/some_resource") var data map[string]interface{} if err := ref.Get(ctx, &data); err != nil { log.Fatalln("Error reading from database:", err) } fmt.Println(data)
在某些情況下,您可能想要縮小管理 SDK 的範圍以充當未經身份驗證的用戶端。您可以透過為資料庫身份驗證變數覆寫提供null
值來實現此目的。
爪哇
// Fetch the service account key JSON file contents FileInputStream serviceAccount = new FileInputStream("path/to/serviceAccountCredentials.json"); FirebaseOptions options = new FirebaseOptions.Builder() .setCredential(FirebaseCredentials.fromCertificate(serviceAccount)) // The database URL depends on the location of the database .setDatabaseUrl("https://DATABASE_NAME.firebaseio.com") .setDatabaseAuthVariableOverride(null) .build(); FirebaseApp.initializeApp(options); // The app only has access to public data as defined in the Security Rules DatabaseReference ref = FirebaseDatabase .getInstance() .getReference("/public_resource"); ref.addListenerForSingleValueEvent(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { String res = dataSnapshot.getValue(); System.out.println(res); } });
Node.js
var admin = require("firebase-admin"); // Fetch the service account key JSON file contents var serviceAccount = require("path/to/serviceAccountKey.json"); // Initialize the app with a null auth variable, limiting the server's access admin.initializeApp({ credential: admin.credential.cert(serviceAccount), // The database URL depends on the location of the database databaseURL: "https://DATABASE_NAME.firebaseio.com", databaseAuthVariableOverride: null }); // The app only has access to public data as defined in the Security Rules var db = admin.database(); var ref = db.ref("/public_resource"); ref.once("value", function(snapshot) { console.log(snapshot.val()); });
Python
import firebase_admin from firebase_admin import credentials from firebase_admin import db # Fetch the service account key JSON file contents cred = credentials.Certificate('path/to/serviceAccountKey.json') # Initialize the app with a None auth variable, limiting the server's access firebase_admin.initialize_app(cred, { 'databaseURL': 'https://databaseName.firebaseio.com', 'databaseAuthVariableOverride': None }) # The app only has access to public data as defined in the Security Rules ref = db.reference('/public_resource') print(ref.get())
去
ctx := context.Background() // Initialize the app with a nil auth variable, limiting the server's access var nilMap map[string]interface{} conf := &firebase.Config{ DatabaseURL: "https://databaseName.firebaseio.com", AuthOverride: &nilMap, } // Fetch the service account key JSON file contents opt := option.WithCredentialsFile("path/to/serviceAccountKey.json") app, err := firebase.NewApp(ctx, conf, opt) if err != nil { log.Fatalln("Error initializing app:", err) } client, err := app.Database(ctx) if err != nil { log.Fatalln("Error initializing database client:", err) } // The app only has access to public data as defined in the Security Rules ref := client.NewRef("/some_resource") var data map[string]interface{} if err := ref.Get(ctx, &data); err != nil { log.Fatalln("Error reading from database:", err) } fmt.Println(data)