Kafka Upstream: Send messages to multiple topics - Plugin

Send messages to multiple topics

As of Kong Gateway 3.10, the Kafka Upstream plugin supports sending messages to multiple Kafka topics specified by the client through a query parameter. To control which topics clients can target, you can configure an allowlist of permitted topic names.

Clients can use the topic-list query parameter to send a message to one or more topics. These can include topics listed in the allowed_topic configuration, as well as the default topic specified in the topic field.

Example: curl http://localhost:8000/kafka?topic-list=my-topic,topic1

Prerequisites

Kafka installed and running
Create a Kafka topic

Environment variables

KAFKA_TOPIC: The name of your Kafka topic

Set up the plugin

Add this section to your declarative configuration file:

_format_version: "3.0"
plugins:
  - name: kafka-upstream
    config:
      topic: ${{ env "DECK_KAFKA_TOPIC" }}
      bootstrap_servers:
      - host: localhost
        port: 9092
      topics_query_arg: topic-list
      allowed_topics:
      - my-topic
      - topic1
      - topic2

Make the following request:

curl -i -X POST http://localhost:8001/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "kafka-upstream",
      "config": {
        "topic": "'$KAFKA_TOPIC'",
        "bootstrap_servers": [
          {
            "host": "localhost",
            "port": 9092
          }
        ],
        "topics_query_arg": "topic-list",
        "allowed_topics": [
          "my-topic",
          "topic1",
          "topic2"
        ]
      }
    }
    '

Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "kafka-upstream",
      "config": {
        "topic": "'$KAFKA_TOPIC'",
        "bootstrap_servers": [
          {
            "host": "localhost",
            "port": 9092
          }
        ],
        "topics_query_arg": "topic-list",
        "allowed_topics": [
          "my-topic",
          "topic1",
          "topic2"
        ]
      }
    }
    '

Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongClusterPlugin
metadata:
  name: kafka-upstream
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
  labels:
    global: 'true'
config:
  topic: '$KAFKA_TOPIC'
  bootstrap_servers:
  - host: localhost
    port: 9092
  topics_query_arg: topic-list
  allowed_topics:
  - my-topic
  - topic1
  - topic2
plugin: kafka-upstream
" | kubectl apply -f -

Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_kafka_upstream" "my_kafka_upstream" {
  enabled = true

  config = {
    topic = var.kafka_topic
    bootstrap_servers = [
      {
        host = "localhost"
        port = 9092
      }    ]
    topics_query_arg = "topic-list"
    allowed_topics = ["my-topic", "topic1", "topic2"]
  }

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
}

This example requires the following variables to be added to your manifest. You can specify values at runtime by setting TF_VAR_name=value.

variable "kafka_topic" {
  type = string
}

Add this section to your declarative configuration file:

_format_version: "3.0"
plugins:
  - name: kafka-upstream
    service: serviceName|Id
    config:
      topic: ${{ env "DECK_KAFKA_TOPIC" }}
      bootstrap_servers:
      - host: localhost
        port: 9092
      topics_query_arg: topic-list
      allowed_topics:
      - my-topic
      - topic1
      - topic2

Make sure to replace the following placeholders with your own values:

serviceName|Id: The id or name of the service the plugin configuration will target.

Make the following request:

curl -i -X POST http://localhost:8001/services/{serviceName|Id}/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "kafka-upstream",
      "config": {
        "topic": "'$KAFKA_TOPIC'",
        "bootstrap_servers": [
          {
            "host": "localhost",
            "port": 9092
          }
        ],
        "topics_query_arg": "topic-list",
        "allowed_topics": [
          "my-topic",
          "topic1",
          "topic2"
        ]
      }
    }
    '

Make sure to replace the following placeholders with your own values:

serviceName|Id: The id or name of the service the plugin configuration will target.

Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/services/{serviceId}/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "kafka-upstream",
      "config": {
        "topic": "'$KAFKA_TOPIC'",
        "bootstrap_servers": [
          {
            "host": "localhost",
            "port": 9092
          }
        ],
        "topics_query_arg": "topic-list",
        "allowed_topics": [
          "my-topic",
          "topic1",
          "topic2"
        ]
      }
    }
    '

Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.
serviceId: The id of the service the plugin configuration will target.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: kafka-upstream
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
config:
  topic: '$KAFKA_TOPIC'
  bootstrap_servers:
  - host: localhost
    port: 9092
  topics_query_arg: topic-list
  allowed_topics:
  - my-topic
  - topic1
  - topic2
plugin: kafka-upstream
" | kubectl apply -f -

Next, apply the KongPlugin resource by annotating the service resource:

kubectl annotate -n kong service SERVICE_NAME konghq.com/plugins=kafka-upstream

Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_kafka_upstream" "my_kafka_upstream" {
  enabled = true

  config = {
    topic = var.kafka_topic
    bootstrap_servers = [
      {
        host = "localhost"
        port = 9092
      }    ]
    topics_query_arg = "topic-list"
    allowed_topics = ["my-topic", "topic1", "topic2"]
  }

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
  service = {
    id = konnect_gateway_service.my_service.id
  }
}

This example requires the following variables to be added to your manifest. You can specify values at runtime by setting TF_VAR_name=value.

variable "kafka_topic" {
  type = string
}

Add this section to your declarative configuration file:

_format_version: "3.0"
plugins:
  - name: kafka-upstream
    route: routeName|Id
    config:
      topic: ${{ env "DECK_KAFKA_TOPIC" }}
      bootstrap_servers:
      - host: localhost
        port: 9092
      topics_query_arg: topic-list
      allowed_topics:
      - my-topic
      - topic1
      - topic2

Make sure to replace the following placeholders with your own values:

routeName|Id: The id or name of the route the plugin configuration will target.

Make the following request:

curl -i -X POST http://localhost:8001/routes/{routeName|Id}/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "kafka-upstream",
      "config": {
        "topic": "'$KAFKA_TOPIC'",
        "bootstrap_servers": [
          {
            "host": "localhost",
            "port": 9092
          }
        ],
        "topics_query_arg": "topic-list",
        "allowed_topics": [
          "my-topic",
          "topic1",
          "topic2"
        ]
      }
    }
    '

Make sure to replace the following placeholders with your own values:

routeName|Id: The id or name of the route the plugin configuration will target.

Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/routes/{routeId}/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "kafka-upstream",
      "config": {
        "topic": "'$KAFKA_TOPIC'",
        "bootstrap_servers": [
          {
            "host": "localhost",
            "port": 9092
          }
        ],
        "topics_query_arg": "topic-list",
        "allowed_topics": [
          "my-topic",
          "topic1",
          "topic2"
        ]
      }
    }
    '

Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.
routeId: The id of the route the plugin configuration will target.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: kafka-upstream
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
config:
  topic: '$KAFKA_TOPIC'
  bootstrap_servers:
  - host: localhost
    port: 9092
  topics_query_arg: topic-list
  allowed_topics:
  - my-topic
  - topic1
  - topic2
plugin: kafka-upstream
" | kubectl apply -f -

Next, apply the KongPlugin resource by annotating the httproute or ingress resource:

kubectl annotate -n kong httproute  konghq.com/plugins=kafka-upstream

kubectl annotate -n kong ingress  konghq.com/plugins=kafka-upstream

Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_kafka_upstream" "my_kafka_upstream" {
  enabled = true

  config = {
    topic = var.kafka_topic
    bootstrap_servers = [
      {
        host = "localhost"
        port = 9092
      }    ]
    topics_query_arg = "topic-list"
    allowed_topics = ["my-topic", "topic1", "topic2"]
  }

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
  route = {
    id = konnect_gateway_route.my_route.id
  }
}

This example requires the following variables to be added to your manifest. You can specify values at runtime by setting TF_VAR_name=value.

variable "kafka_topic" {
  type = string
}

Add this section to your declarative configuration file:

_format_version: "3.0"
plugins:
  - name: kafka-upstream
    consumer: consumerName|Id
    config:
      topic: ${{ env "DECK_KAFKA_TOPIC" }}
      bootstrap_servers:
      - host: localhost
        port: 9092
      topics_query_arg: topic-list
      allowed_topics:
      - my-topic
      - topic1
      - topic2

Make sure to replace the following placeholders with your own values:

consumerName|Id: The id or name of the consumer the plugin configuration will target.

Make the following request:

curl -i -X POST http://localhost:8001/consumers/{consumerName|Id}/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "kafka-upstream",
      "config": {
        "topic": "'$KAFKA_TOPIC'",
        "bootstrap_servers": [
          {
            "host": "localhost",
            "port": 9092
          }
        ],
        "topics_query_arg": "topic-list",
        "allowed_topics": [
          "my-topic",
          "topic1",
          "topic2"
        ]
      }
    }
    '

Make sure to replace the following placeholders with your own values:

consumerName|Id: The id or name of the consumer the plugin configuration will target.

Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/consumers/{consumerId}/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "kafka-upstream",
      "config": {
        "topic": "'$KAFKA_TOPIC'",
        "bootstrap_servers": [
          {
            "host": "localhost",
            "port": 9092
          }
        ],
        "topics_query_arg": "topic-list",
        "allowed_topics": [
          "my-topic",
          "topic1",
          "topic2"
        ]
      }
    }
    '

Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.
consumerId: The id of the consumer the plugin configuration will target.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: kafka-upstream
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
config:
  topic: '$KAFKA_TOPIC'
  bootstrap_servers:
  - host: localhost
    port: 9092
  topics_query_arg: topic-list
  allowed_topics:
  - my-topic
  - topic1
  - topic2
plugin: kafka-upstream
" | kubectl apply -f -

Next, apply the KongPlugin resource by annotating the KongConsumer resource:

kubectl annotate -n kong  CONSUMER_NAME konghq.com/plugins=kafka-upstream

Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_kafka_upstream" "my_kafka_upstream" {
  enabled = true

  config = {
    topic = var.kafka_topic
    bootstrap_servers = [
      {
        host = "localhost"
        port = 9092
      }    ]
    topics_query_arg = "topic-list"
    allowed_topics = ["my-topic", "topic1", "topic2"]
  }

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
  consumer = {
    id = konnect_gateway_consumer.my_consumer.id
  }
}

This example requires the following variables to be added to your manifest. You can specify values at runtime by setting TF_VAR_name=value.

variable "kafka_topic" {
  type = string
}

Kafka Upstream

Send messages to multiple topics

Prerequisites

Environment variables

Set up the plugin

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