The MongoDB Kafka sink connector is a Kafka Connect connector that reads data from Kafka topics and writes data to MongoDB.

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Prerequisites

  • Valid credentials with the readWrite role on the database. For more granular access control, you can specify a custom role that allows insert, remove, and update actions on the databases or collections.
  • The connection.uri is in form of mongodb+srv://username:password@cluster0.xxx.mongodb.net

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Quick Start

  1. Setup the kcctl client: doc

  2. Create a MongoDB Cluster, you can create one in k8s cluster with below yaml file:

    apiVersion: v1
kind: Service
metadata:
  name: mongo
  labels:
    name: mongo
spec:
  ports:
    - port: 27017
  clusterIP: None
  selector:
    role: mongo
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mongo-dbz
spec:
  selector:
    matchLabels:
      role: mongo
  serviceName: "mongo"
  replicas: 1
  template:
    metadata:
      labels:
        role: mongo
    spec:
      terminationGracePeriodSeconds: 10
      containers:
        - name: mongo
          image: debezium/example-mongodb:2.6
          env:
            - name: MONGODB_USER
              value: "debezium"
            - name: MONGODB_PASSWORD
              value: "dbz"
          command:
            - mongod
            - "--replSet"
            - rs0
            - "--bind_ip" # bind mongo to all ip address to allow others to access
            - "0.0.0.0"
          ports:
            - containerPort: 27017
        - name: mongo-sidecar
          image: cvallance/mongo-k8s-sidecar
          env:
            - name: MONGO_SIDECAR_POD_LABELS
              value: "role=mongo"
            - name: KUBE_NAMESPACE
              value: default
            - name: KUBERNETES_MONGO_SERVICE_NAME
              value: "mongo"

  3. Initialize the local MongoDB cluster:

    kubectl apply -f .ci/clusters/mongodb.yaml
kubectl wait -l role=mongo --for=condition=Ready pod --timeout=5m
# initialize the data
kubectl exec mongo-dbz-0 -c mongo -- bash ./usr/local/bin/init-inventory.sh

  4. Create a JSON file like the following:

    {
    "name": "mongo-sink",
    "config": {
        "connector.class": "com.mongodb.kafka.connect.MongoSinkConnector",
        "connection.uri": "mongodb://mongo.default.svc.cluster.local:27017/?authSource=admin",
        "database": "kafka-mongo-sink",
        "topics": "kafka-mongo-input",
        "value.converter": "org.apache.kafka.connect.json.JsonConverter",
        "value.converter.schemas.enable": false,
        "tasks.max": "1"
    }
}

  5. Run the following command to create the connector:

    kcctl create -f <filename>.json

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Limitations

If you want to use the MongoDB CDC handler for data sourced from MongoDB instances by MongoDB source connector, you will need to select STRING or BYTES as the value converter for both MongoDB source and MongoDB sink connectors. Details can be found here.

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Configuration

The MongoDB Kafka sink connector is configured using the following Required properties:

ParameterDescription
connection.uriThe connection URI for the MongoDB server.
databaseThe MongoDB database name.
topicsA list of Kafka topics that the sink connector watches. (You can define either the topics or the topics.regex setting, but not both.)
topics.regexA regular expression that matches the Kafka topics that the sink connector watches. (You can define either the topics or the topics.regex setting, but not both.)

The full properties are also available from the offical MongoDB Kafka Sink Connector documentation.