// Module included in the following assemblies:
//
// assembly-config.adoc

[id='con-config-kafka-bridge-{context}']
= Configuring the Kafka Bridge

[role="_abstract"]
Update the `spec` properties of the `KafkaBridge` custom resource to configure your Kafka Bridge deployment.

In order to prevent issues arising when client consumer requests are processed by different Kafka Bridge instances, address-based routing must be employed to ensure that requests are routed to the right Kafka Bridge instance.
Additionally, each independent Kafka Bridge instance must have a replica.
A Kafka Bridge instance has its own state which is not shared with another instances.

For a deeper understanding of the Kafka Bridge and its cluster configuration options, refer to the link:{BookURLBridge}[Using the Kafka Bridge^] guide and the link:{BookURLConfiguring}[Strimzi Custom Resource API Reference^].

.Example `KafkaBridge` custom resource configuration
[source,yaml,subs="+quotes,attributes"]
----
# Basic configuration (required)
apiVersion: {KafkaBridgeApiVersion}
kind: KafkaBridge
metadata:
  name: my-bridge
spec:
  # Replicas (required)
  replicas: 3 # <1>
  # Kafka bootstrap servers (required)
  bootstrapServers: _<cluster_name>_-cluster-kafka-bootstrap:9092 # <2>
  # HTTP configuration (required)
  http: # <3>
    port: 8080
    # CORS configuration (optional)
    cors: # <4>
      allowedOrigins: "https://strimzi.io"
      allowedMethods: "GET,POST,PUT,DELETE,OPTIONS,PATCH"
  # Resources requests and limits (recommended)
  resources: # <5>
    requests:
      cpu: "1"
      memory: 2Gi
    limits:
      cpu: "2"
      memory: 2Gi
  # TLS configuration (optional)
  tls: # <6>
    trustedCertificates:
      - secretName: my-cluster-cluster-cert
        pattern: "*.crt"
      - secretName: my-cluster-cluster-cert
        certificate: ca2.crt
  # Authentication (optional)
  authentication: # <7>
    type: tls
    certificateAndKey:
      secretName: my-secret
      certificate: public.crt
      key: private.key
  # Consumer configuration (optional)
  consumer: # <8>
    config:
      auto.offset.reset: earliest
  # Producer configuration (optional)
  producer: # <9>
    config:
      delivery.timeout.ms: 300000
  # Logging configuration (optional)
  logging: # <10>
    type: inline
    loggers:
      rootLogger.level: INFO
      # Enabling DEBUG just for send operation
      logger.send.name: http.openapi.operation.send
      logger.send.level: DEBUG
  # JVM options (optional)
  jvmOptions: # <11>
    "-Xmx": "1g"
    "-Xms": "1g"
  # Readiness probe (optional)
  readinessProbe: # <12>
    initialDelaySeconds: 15
    timeoutSeconds: 5
  # Liveness probe (optional)
  livenessProbe:
    initialDelaySeconds: 15
    timeoutSeconds: 5
  # Custom image (optional)
  image: my-org/my-image:latest # <13>
  # Pod template (optional)
  template: # <14>
    pod:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: application
                    operator: In
                    values:
                      - postgresql
                      - mongodb
              topologyKey: "kubernetes.io/hostname"
    bridgeContainer: # <15>
      env:
        - name: OTEL_SERVICE_NAME
          value: my-otel-service
        - name: OTEL_EXPORTER_OTLP_ENDPOINT
          value: "http://otlp-host:4317"
  # Tracing configuration (optional)
  tracing:
    type: opentelemetry # <16>
----
<1> The number of replica nodes.
<2> Bootstrap address for connection to the target Kafka cluster. The address takes the format `<cluster_name>-kafka-bootstrap:<port_number>`. The Kafka cluster doesn't need to be managed by Strimzi or deployed to a Kubernetes cluster.
<3> HTTP access to Kafka brokers.
<4> CORS access specifying selected resources and access methods. Additional HTTP headers in requests describe the origins that are permitted access to the Kafka cluster.
<5> Requests for reservation of supported resources, currently `cpu` and `memory`, and limits to specify the maximum resources that can be consumed.
<6> TLS configuration for encrypted connections to the Kafka cluster, with trusted certificates stored in X.509 format within the specified secrets.
<7> Authentication for the Kafka Bridge cluster, specified as mTLS, token-based OAuth, SASL-based SCRAM-SHA-256/SCRAM-SHA-512, or PLAIN.
By default, the Kafka Bridge connects to Kafka brokers without authentication.
<8> Consumer configuration options.
<9> Producer configuration options.
<10> Kafka Bridge loggers and log levels added directly (`inline`) or indirectly (`external`) through a `ConfigMap`. Custom Log4j configuration must be placed under the `log4j2.properties` key in the `ConfigMap`. You can set log levels to `INFO`, `ERROR`, `WARN`, `TRACE`, `DEBUG`, `FATAL` or `OFF`.
<11> JVM configuration options to optimize performance for the Virtual Machine (VM) running the Kafka Bridge.
<12> Healthchecks to know when to restart a container (liveness) and when a container can accept traffic (readiness).
<13> Optional: Container image configuration, which is recommended only in special situations.
<14> Template customization. Here a pod is scheduled with anti-affinity, so the pod is not scheduled on nodes with the same hostname.
<15> Environment variables are set for distributed tracing.
<16> Distributed tracing is enabled by using OpenTelemetry.