---
title: "Kafka CLI"
url: "https://vanducng.dev/2020/06/22/Kafka-CLI/"
date: "2020-06-22"
categories: ["Data"]
tags: ["kafka"]
---

# Kafka CLI

![kafka-cli.png](https://vanducng.dev/2020/06/22/Kafka-CLI/kafka-cli.png)

Once working with Kafka, I often need to quickly interact with Kafka cluster via command line. This post is my collection of frequent commands used in daily work with projects having Kafka integrated.

## Listing topics

```bash
kafka-topics --list --zookeeper localhost:2181
```

* The `--list` switch tells the kafka-topics CLI to list all known topics.
* The `--zookeeper localhost:2181` switch tells the kafka-topics CLI where the Zookeeper ensemble Kafka is using is located. Note that in the newest versions of Kafka the `--zookeeper` switch is deprecated in favor of a `--bootstrap-server` switch that points to Kafka. The `--zookeeper` switch still works, but will likely be dropped in the next major revision of Kafka.

## Creating topics
```bash
kafka-topics --create --topic "my-first-topic" --partitions 1 --replication-factor 1 --zookeeper localhost:2181
```
* The switch `--topic "my-first-topic"` tells Kafka what to name the topic
* The switch `--partitions 1` and the switch `--replication-factor 1` are required configuration
* To check that our topic was successfully created, let's repeat the command to list topics with a slight modification:
  ```bash
  kafka-topics --list --zookeeper localhost:2181 --topic "my-first-topic"
  ```

## Producing data
```bash
kafka-console-producer --topic "my-first-topic" --broker-list PLAINTEXT://localhost:9092
```
* The switch `--broker-list` serves the same purpose as `--zookeeper` for the kafka-topics command, it simply tells the tool where to find Kafka.
* Try typing out a few messages and hitting enter.
  ```bash
  root@6b48dc2bd81c:/# kafka-console-producer --topic "my-first-topic" --broker-list PLAINTEXT://localhost:9092
  >hello
  >world!
  >my
  >first
  >kafka
  >events!
  >
  ```

## Consuming data
```bash
kafka-console-consumer --topic "my-first-topic" --bootstrap-server PLAINTEXT://localhost:9092 --from-beginning
```
* The `--from-beginning` switch tells kafka-console-consumer to read data from the beginning of the topic, not just data from when we connect.
* By default Kafka doesn't provide historical messages to new consumers
* You should now see output that includes all of the messages you've produced:
  ```bash
  root@6b48dc2bd81c:/# kafka-console-consumer --topic "my-first-topic" --bootstrap-server PLAINTEXT://localhost:9092 --from-beginning
  hello
  world!
  my
  first
  kafka
  events!
  hello again!
  ```

## Deleting topics
```bash
kafka-topics --delete --topic "my-first-topic" --zookeeper localhost:2181
```
* This command is nearly identical to the --create command from earlier, except now we're calling the command with the --delete switch instead.
* This command does not print any output if it's successful. To check that your topic is actually deleted, list the topics one more time:
  ```bash
  kafka-topics --list --zookeeper localhost:2181
  ```

## Describe topic
```bash
kafka-topics --describe --zookeeper localhost:2181 --topic topic_name
```
* This is helpful once there is a need of understanding how data is managed by Kafka.