Lenses® for Apache Kafka

This is the official Docker for Lenses that enables you to:

• View and Query Kafka Topic Data (Avro & JSon) - Browse and query with Lenses SQL
• View data topologies and monitor every aspect of your Kafka cluster
• View and manage your Data Schemas
• Build and monitor ETL pipelines with open source Kafka Connectors
• Execute KStreams processors instrumented in SQL in Kubernetes or Connector workers
• Set up alerting and external notifications on liveniness of streaming systems
• Data governance: Auditing on all actions, data lineage & multi-tenancy
• Fine-grained security. Role based access with LDAP support
• Manage Quotas, ACLs

As a state-less application lenses fits naturally in containers and run on Kubernetes or Openshift. It integrates and helps you instrument and view your streaming data pipelines; as well as operate them with confidence !

The documentation is always available at https://docs.lenses.io and data engineering talk is on Slack

The Docker Image

Please check out the docker image documentation at docs.lenses.io for the most recent docs and the complete set of features, settings and tweak knobs.

This image is aimed for our enterprise clients, though anyone with a free developer license may use it. Visit our download page to get a free developer license or an enterprise trial. Only Lenses is included in this docker. Our development environment image, which additionally includes Kafka, Connect, Schema Registry and our open-source Stream Reactor collection of connectors can be found as landoop/kafka-lenses-dev.

This image has to be run alongside a Kafka cluster.

How to run

In the current iteration landoop/lenses uses environment variables as the primary means for configuration and alternatively configuration files.

Setup with environment variables

For any lenses configuration option, set an environment variable by converting the option name to uppercase and with dots replaced by underscores. As an example lenses.port should be converted to LENSES_PORT. Optionally settings may be mount as volumes under /mnt/settings or /mnt/secrets. As an example you could set —file— volume /mnt/settings/LENSES_PORT with the port number as the content of the file.

A brief example of a docker-compose file to setup Lenses, would be:

version: '2'
services:
  lenses:
    image: lensesio/lenses
    environment:
      LENSES_PORT: 9991
      LENSES_KAFKA_BROKERS: "PLAINTEXT://broker.1.url:9092,PLAINTEXT://broker.2.url:9092"

      # # If you have enabled JMX for your brokers, set the port here
      # LENSES_KAFKA_METRICS_DEFAULT_PORT: 9581

      # # If you use AVRO, configure the Schema Registry
      # LENSES_SCHEMA_REGISTRY_URLS: |
      #   [
      #     {url:"http://schema.registry.1.url:8081"},
      #     {url:"http://schema.registry.2.url:8081"}
      #   ]

      # # If you use Kafka Connect, configure the workers.
      # LENSES_KAFKA_CONNECT_CLUSTERS: |
      #   [
      #     {
      #       name:"data_science",
      #       urls: [
      #         {url:"http://connect.worker.1.url:8083"},
      #         {url:"http://connect.worker.2.url:8083"}
      #       ],
      #       statuses:"connect-statuses-cluster-a",
      #       configs:"connect-configs-cluster-a",
      #       offsets:"connect-offsets-cluster-a"
      #     }
      #   ]

      # # Zookeeper access is optional
      # LENSES_ZOOKEEPER_HOSTS: |
      #   [
      #     {url:"zookeeper.1.url:2181"},
      #     {url:"zookeeper.2.url:2181"}
      #   ]

      # # Users are managed within Lenses. Here you can change the superuser username:
      # LENSES_SECURITY_USER: admin
      # # Users are managed within Lenses. Here you can change the superuser password:
      # LENSES_SECURITY_PASSWORD: admin
    ports:
      - 9991:9991
      - 9102:9102
    volumes:
      - ./license.json:/license.json
    network_mode: host

The docker image has two volumes where data are saved: /data/log for logs and /data/kafka-streams-state for storing the state of Lenses SQL processors. Depending on your queries and the topics volume, the latter can become pretty large. You should monitor space and plan for adequate capacity. Maintaining the streams state directory between Lenses restarts is mandatory for the SQL processors to be able to continue from where they left.

The container starts with root privileges and drops to nobody:nogroup (65534:65534) before running Lenses. If you start the image as a custom user:group, it falls under your responsibility to make sure that the two volumes are writeable by the custom user:group.

Setup with configuration files

Lenses software configuration is driven by two files: lenses.conf and security.conf. In the docker image we create them automatically from environment variables but it is possible to set directly these files instead.

Create your configuration files according to the documentation and mount them under /mnt/settings and /mnt/secrets respectively —i.e /mnt/settings/lenses.conf and /mnt/secrets/security.conf. You can set either one or both together. Please for lenses.conf omit the settings lenses.secret.file and lenses.license.file. If by any chance you set them, you have to make sure lenses can find the files described in these settings.

The license file

Lenses require a license file in order to start. It may be passed to the container via three methods:

• As a file, mounted at /license.json or /mnt/secrets/license.json (e.g -v /path/to/license.json:/license.json)
• As the contents of the environment variable LICENSE (e.g -e LICENSE="$(cat license.json)")
• As a downloadable URL via LICENSE_URL (e.g -e LICENSE_URL="https://license.url/")

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For more information, please visit our documentation. Enterprise customers may use the support channels made available to them. Developer Edition users are encouraged to visit our slack community. We are always happy to help and hear from you.

With respect,

The Lenses Team.

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Copyright 2017-2019, Lenses.io Ltd