kcctl -- A CLI for Apache Kafka Connect

This project is a command-line client for Kafka Connect. Relying on the idioms and semantics of kubectl, it allows you to register and examine connectors, delete them, restart them, etc.

Usage

Display the help to learn about using kcctl:

kcctl help
Usage: kcctl [COMMAND]
A command-line interface for Kafka Connect
Commands:
  info      Displays information about the Kafka Connect cluster
  config    Sets or retrieves the configuration of this client
  get       Displays information about connector plug-ins, connectors and log level of connectors
  delete    Deletes the specified connector
  restart   Restarts the specified connector or task
  describe  Displays detailed information about the specified resource
  apply     Applies the given file for registering or updating a connector
  patch     Applies the patch to the connector depending on subcommand. (e.g. Changing log level at runtime) 
  help      Displays help information about the specified command

It is recommended to install the bash/zsh completion script kcctl_completion:

. kcctl_completion

Development

This project uses Quarkus, the Supersonic Subatomic Java Framework.

If you want to learn more about Quarkus, please visit its website: https://quarkus.io/ .

Running the application in dev mode

You can run your application in dev mode that enables live coding using:

./mvnw compile quarkus:dev

Add a remote debugger in Intellij

Default port is 5005, execute below script in debug mode and start the debugger. It will hit the breakpoint

mvn compile quarkus:dev -Dquarkus.args='patch get connectors' -Dsuspend

Packaging and running the application

The application can be packaged using:

./mvnw package

It produces the quarkus-run.jar file in the target/quarkus-app/ directory. Be aware that it’s not an über-jar as the dependencies are copied into the target/quarkus-app/lib/ directory.

The application is now runnable using java -jar target/quarkus-app/quarkus-run.jar. You should define an alias kcctl:

alias kcctl="java -jar target/quarkus-app/quarkus-run.jar"

Creating a native executable

You can create a native executable using:

./mvnw package -Pnative

You can then execute your native executable with: ./target/code-with-quarkus-1.0.0-SNAPSHOT-runner

As above, either define an alias kcctl or rename the resulting executable accordingly.

Updating the Completion Script

Grep for usages of DummyCompletions and uncomment them (they are used as placeholders in the generated completion script).

Build the application in JVM mode.

Recreate the completion script:

java -cp "target/quarkus-app/app/*:target/quarkus-app/lib/main/*:target/quarkus-app/quarkus-run.jar" picoclutoutoComplete -n kcctl --force dev.morling.kccli.command.KcCtlCommand

Edit the completion scrpt kcctl_completion, replace all the dummy completion placeholders with invocations of one of the (hidden) completion candidate commands, e.g. like so:

--- local CONNECTOR_NAME_pos_param_args="connector-1 connector-2 connector-3" # 0-0 values
+++ local CONNECTOR_NAME_pos_param_args=`kcctl connector-name-completions` # 0-0 values

Related Quarkus Guides

• Picocli (guide): Develop command line applications with Picocli
• Quarkus native apps (guide): Develop native applications with Quarkus and GraalVM

License

This code base is available ander the Apache License, version 2.