krs

krs is a simple Kafka command-line tool written in Rust, inspired by kt.

Dual-licensed under MIT or the UNLICENSE.

Features

• Easy to type
• Fast startup (thanks Rust!)
• Hopefully intuitive to use.
• Diagnostic output to stderr, main output to stdout, which allows below feature
• JSON output for easy consumption with jq
• Change some context variables (e.g. Kafka brokers or Zookeeper host) via environment variables, .env files, or pass it directly through the CLI.

Walkthrough

First and foremost, always consult -h or help (or let me know if some stuff is unclear). ```bash krs -h krs help

All subcommands also have help, thanks to the amazing clap library.

krs env help ```

krs collects Kafka brokers and Zookeeper hosts from environment variables, .env file, and the CLI arguments as its context. To show context variables: bash $ krs env show # or just `krs env`

If in doubt, you can always ask the tool which environment you're currently working on: $ cat .env KRS_ZOOKEEPER=localhost:2181 $ export KRS_BROKERS=localhost:9092 $ krs env show Environment: brokers: localhost:2181 (from env var (KRS_BROKERS)) zookeeper: localhost:9092 (from .env file (KRS_ZOOKEEPER))

There's a small helper to set the context variables (or you can just put the environment variables KRS_BROKERS/KRS_ZOOKEEPER in your .env file directly): $ krs env set -b localhost:9092 -z localhost:2181

Once you've set context variables, you can list Kafka topics: ``bash krs topics list # or justkrs topics`

You should pipe the output to jq to make it look much better.

krs topics | jq ```

Describe a Kafka topic: bash krs topics describe -b localhost:9092 -z localhost:2181 -t topic-name

Produce and consume from topics: ``` krs topics create -t my-topic krs producer -t my-topic Starting console producer. Press Ctrl+C to exit.

hello Sent: (0, 1) ```

Compatibility

MSRV is Rust 1.39.0 (mostly because I built the tool with that version and haven't tested it with previous ones).

Mostly tested with Kafka 2.1.1-cp1 (Commit:9aa84c2aaa91e392).

Caveats

At the moment, I'm depending on an unpublished version of rust-rdkafka to get access to the AdminClient. When this issue is fixed, I'll fix this on my side.

Upcoming Features

Note: There will be no guarantees as to when these features are going to be implemented, but feel free to submit a PR.

• Consume from specified offset (earliest, latest, etc.)
• Describe configs for other Kafka resources (consumer groups, etc.)
• Port more management commands
• Bit more fine-grained control for producer (handle keys, send to partitions)
• More colors on the stderr output.

Why?

• Typing kafka-console-consumer --broker-list localhost:9092 --topic test is a mouthful.
• In cases you forgot the arguments to kafka-topics --create, the tool will bombard you with its complete list of options, burying the most important error message that tells you what arguments you're missing.
• JVM startup is annoyingly slow for simple CLI tools.
• RIIR, but in good spirit! I think the tool where the inspiration came from was already a fantastic idea.
• But most importantly, I just needed a Rust project to learn Rust! :)