Kafka Bridge

The technical documentation of the kafka-bridge microservice, which acts as a communication bridge between two Kafka brokers.

3 minute read

Kubernetes resources

Deployment: united-manufacturing-hub-kafkabridge
Secret:
- Local broker: united-manufacturing-hub-kafkabridge-secrets-local
- Remote broker: united-manufacturing-hub-kafkabridge-secrets-remote

Configuration

You can configure the kafka-bridge microservice by setting the following values in the _000_commonConfig.kafkaBridge section of the Helm chart values file.

  kafkaBridge:
    enabled: true
    remotebootstrapServer: ""
    topicmap:
      - bidirectional: false
        name: HighIntegrity
        send_direction: to_remote
        topic: ^ia\..+\..+\..+\.((addMaintenanceActivity)|(addOrder)|(addParentToChild)|(addProduct)|(addShift)|(count)|(deleteShiftByAssetIdAndBeginTimestamp)|(deleteShiftById)|(endOrder)|(modifyProducedPieces)|(modifyState)|(productTag)|(productTagString)|(recommendation)|(scrapCount)|(startOrder)|(state)|(uniqueProduct)|(scrapUniqueProduct))$
      - bidirectional: false
        name: HighThroughput
        send_direction: to_remote
        topic: ^ia\..+\..+\..+\.(processValue).*$

Topic Map schema

The topic map is a list of objects, each object represents a topic (or a set of topics) that should be forwarded. The following JSON schema describes the structure of the topic map:

{
    "$schema": "http://json-schema.org/draft-07/schema",
    "type": "array",
    "title": "Kafka Topic Map",
    "description": "This schema validates valid Kafka topic maps.",
    "default": [],
    "additionalItems": true,
    "items": {
        "$id": "#/items",
        "anyOf": [
            {
                "$id": "#/items/anyOf/0",
                "type": "object",
                "title": "Unidirectional Kafka Topic Map with send direction",
                "description": "This schema validates entries, that are unidirectional and have a send direction.",
                "default": {},
                "examples": [
                    {
                        "name": "HighIntegrity",
                        "topic": "^ia\\..+\\..+\\..+\\.(?!processValue).+$",
                        "bidirectional": false,
                        "send_direction": "to_remote"
                    }
                ],
                "required": [
                    "name",
                    "topic",
                    "bidirectional",
                    "send_direction"
                ],
                "properties": {
                    "name": {
                        "$id": "#/items/anyOf/0/properties/name",
                        "type": "string",
                        "title": "Entry Name",
                        "description": "Name of the map entry, only used for logging & tracing.",
                        "default": "",
                        "examples": [
                            "HighIntegrity"
                        ]
                    },
                    "topic": {
                        "$id": "#/items/anyOf/0/properties/topic",
                        "type": "string",
                        "title": "The topic to listen on",
                        "description": "The topic to listen on, this can be a regular expression.",
                        "default": "",
                        "examples": [
                            "^ia\\..+\\..+\\..+\\.(?!processValue).+$"
                        ]
                    },
                    "bidirectional": {
                        "$id": "#/items/anyOf/0/properties/bidirectional",
                        "type": "boolean",
                        "title": "Is the transfer bidirectional?",
                        "description": "When set to true, the bridge will consume and produce from both brokers",
                        "default": false,
                        "examples": [
                            false
                        ]
                    },
                    "send_direction": {
                        "$id": "#/items/anyOf/0/properties/send_direction",
                        "type": "string",
                        "title": "Send direction",
                        "description": "Can be either 'to_remote' or 'to_local'",
                        "default": "",
                        "examples": [
                            "to_remote",
                            "to_local"
                        ]
                    }
                },
                "additionalProperties": true
            },
            {
                "$id": "#/items/anyOf/1",
                "type": "object",
                "title": "Bi-directional Kafka Topic Map with send direction",
                "description": "This schema validates entries, that are bi-directional.",
                "default": {},
                "examples": [
                    {
                        "name": "HighIntegrity",
                        "topic": "^ia\\..+\\..+\\..+\\.(?!processValue).+$",
                        "bidirectional": true
                    }
                ],
                "required": [
                    "name",
                    "topic",
                    "bidirectional"
                ],
                "properties": {
                    "name": {
                        "$id": "#/items/anyOf/1/properties/name",
                        "type": "string",
                        "title": "Entry Name",
                        "description": "Name of the map entry, only used for logging & tracing.",
                        "default": "",
                        "examples": [
                            "HighIntegrity"
                        ]
                    },
                    "topic": {
                        "$id": "#/items/anyOf/1/properties/topic",
                        "type": "string",
                        "title": "The topic to listen on",
                        "description": "The topic to listen on, this can be a regular expression.",
                        "default": "",
                        "examples": [
                            "^ia\\..+\\..+\\..+\\.(?!processValue).+$"
                        ]
                    },
                    "bidirectional": {
                        "$id": "#/items/anyOf/1/properties/bidirectional",
                        "type": "boolean",
                        "title": "Is the transfer bidirectional?",
                        "description": "When set to true, the bridge will consume and produce from both brokers",
                        "default": false,
                        "examples": [
                            true
                        ]
                    }
                },
                "additionalProperties": true
            }
        ]
    },
    "examples": [
   {
      "name":"HighIntegrity",
      "topic":"^ia\\..+\\..+\\..+\\.(?!processValue).+$",
      "bidirectional":true
   },
   {
      "name":"HighThroughput",
      "topic":"^ia\\..+\\..+\\..+\\.(processValue).*$",
      "bidirectional":false,
      "send_direction":"to_remote"
   }
]
}

Environment variables

Environment variables
Variable name	Description	Type	Allowed values	Default
`DEBUG_ENABLE_FGTRACE`	Enables the use of the fgtrace library, do not enable in production	string	`true`, `false`	`false`
`KAFKA_GROUP_ID_SUFFIX`	Identifier appended to the kafka group ID, usually a serial number	string	Any	defalut
`KAFKA_SSL_KEY_PASSWORD_LOCAL`	Password for the SSL key pf the local broker	string	Any	""
`KAFKA_SSL_KEY_PASSWORD_REMOTE`	Password for the SSL key of the remote broker	string	Any	""
`KAFKA_TOPIC_MAP`	A json map of the kafka topics should be forwarded	JSON	See below	{}
`KAKFA_USE_SSL`	Enables the use of SSL for the kafka connection	string	`true`, `false`	`false`
`LOCAL_KAFKA_BOOTSTRAP_SERVER`	URL of the local kafka broker, port is required	string	Any valid URL	united-manufacturing-hub-kafka:9092
`LOGGING_LEVEL`	Defines which logging level is used, mostly relevant for developers.	string	PRODUCTION, DEVELOPMENT	PRODUCTION
`MICROSERVICE_NAME`	Name of the microservice (used for tracing)	string	Any	united-manufacturing-hub-kafka-bridge
`REMOTE_KAFKA_BOOTSTRAP_SERVER`	URL of the remote kafka broker	string	Any valid URL	""
`SERIAL_NUMBER`	Serial number of the cluster (used for tracing)	string	Any	defalut

Last modified December 19, 2024: Merge pull request #306 from united-manufacturing-hub/feat/eng-1713/rename-data-model-v1 (667ff8b)