How to List Channels in RabbitMQ: Commands and Examples

To list channels in RabbitMQ, use the rabbitmqctl list_channels command in the terminal or access the Management HTTP API endpoint /api/channels. These methods show active channels with details like connection, user, and state.

Syntax

The primary command to list channels in RabbitMQ is rabbitmqctl list_channels [options]. This command outputs active channels with default columns like pid, connection_name, and state.

You can specify columns to display by adding their names after the command, for example: rabbitmqctl list_channels pid connection_name user.

Alternatively, use the Management HTTP API GET request to /api/channels to get JSON data about channels.

bash

rabbitmqctl list_channels [column1] [column2] ...

Example

This example shows how to list all active channels with their process ID, connection name, user, and state using rabbitmqctl. It also shows how to get channel info via the Management API using curl.

bash

rabbitmqctl list_channels pid connection_name user state

# Example curl command to get channels via HTTP API
curl -u guest:guest http://localhost:15672/api/channels

Output

Listing channels ...
<1234.5678.9> 127.0.0.1:5672 -> 127.0.0.1:12345 guest running
<1234.5678.10> 127.0.0.1:5672 -> 127.0.0.1:12346 guest running

[
  {
    "name": "<1234.5678.9>",
    "user": "guest",
    "state": "running",
    "connection_name": "127.0.0.1:5672 -> 127.0.0.1:12345"
  },
  {
    "name": "<1234.5678.10>",
    "user": "guest",
    "state": "running",
    "connection_name": "127.0.0.1:5672 -> 127.0.0.1:12346"
  }
]

Common Pitfalls

• Running rabbitmqctl list_channels without sufficient permissions may fail; run as a user with RabbitMQ admin rights.
• Using the command on a remote server requires SSH access or running it locally.
• Management API requires the management plugin enabled and correct credentials.
• Not specifying columns shows default columns only, which might miss needed details.

bash

Wrong:
rabbitmqctl list_channels

Right:
rabbitmqctl list_channels pid connection_name user state

Quick Reference

Command / API	Description
rabbitmqctl list_channels	Lists active channels with default columns
rabbitmqctl list_channels pid user state	Lists channels with specified columns
curl -u user:pass http://localhost:15672/api/channels	Fetches channels info via HTTP API in JSON
rabbitmq-plugins enable rabbitmq_management	Enable management plugin to use HTTP API

Key Takeaways

Use 'rabbitmqctl list_channels' to see active channels from the command line.

Specify columns after the command to customize output details.

The Management HTTP API '/api/channels' provides channel info in JSON format.

Ensure you have proper permissions and the management plugin enabled.

Use 'curl' with credentials to access channel info via HTTP API.