You can also configure Scaleway NATS with the Terraform NATS Jetstream provider using our dedicated tutorial.
Using the NATS CLI
The NATS CLI (nats
) is the official NATS tool for managing your NATS resources. It allows you to simply create and manage your streams, consumers and more.
Check out the official NATS CLI documentation for installation instructions, examples and more.
This page shows you how to get started with some basic actions via the NATS CLI.
Before you start
To complete the actions presented below, you must have:
- A Scaleway account logged into the console
- Owner status or IAM permissions allowing you to perform actions in the intended Organization
- A Scaleway NATS account
- NATS credentials downloaded to your machine
Installing the NATS CLI
Follow instructions from the official NATS documentation. The installation process may differ depending on your OS.
Define a context
To simplify your interactions with NATS hosted on Scaleway, we recommend that you use contexts. A context is a named configuration that stores the settings (such as credentials, URLs and certificates) required to connect to NATS. By creating a context, you won’t need to specify your server and credentials with each new request.
Create a context
The example below creates a context named scaleway
.
- Replace
{Scaleway NATS URL}
with the URL of your NATS account (find this in the console on your NATS account Overview tab). - Replace
{path to your creds file}
with the path to the location where you downloaded your.creds
file.
nats context save scaleway --server={Scaleway NATS URL} --creds={path to your creds file}
Use the saved context
Enter the following command to select the scaleway
context for use:
nats context select scaleway
Create a stream
To create a stream, use the command nats stream add
and follow the CLI guidelines.
Bear in mind that:
- Scaleway NATS does not support in-memory streams: choose
File
as storage backend. - Some system limits may apply by default.
- If you choose a
Retention Policy
other thanWork Queue
you will be billed for the messages stored and retained. - Choosing three replicas has an impact on:
- The stream storage limit (as data is replicated 3 times)
- The volume of billed messages
You can connect to your stream using code, devtools or the NATS CLI (for testing purposes only).
NATS cheat sheet
Use the nats cheat
command to get a list of all possible commands.
Below we provide a summary of some useful commands.
General
Action | Command |
---|---|
Show a specific section of cheats | nats cheat pub |
List available sections | nats cheat --sections |
Messaging
Action | Command |
---|---|
Publish message from STDIN | echo "hello world" | nats pub destination.subject |
Publish 100 messages with a random body of 100 - 1000 characters | nats cheat --sections``nats pub destination.subject "{{ Random 100 1000 }}" -H Count:{{ Count }} --count 100 |
Publish message from STDINReceive new messages received with the subject ORDERS.new | nats sub ORDERS.new |
Subscribe to messages, on subject source.subject | nats sub source.subject |
Queuing/Streaming
Action | Command |
---|---|
Adding a stream | nats stream add |
Viewing a stream | nats stream info STREAMNAME |
Removing a stream | nats stream rm STREAMNAME |
Show a list of streams | nats stream list |
Get message 12345 in stream ORDERS | nats stream get ORDERS 12345 |
Delete message 12345 in stream ORDERS | nats stream rmm ORDERS 12345 |
Purge messages from stream ORDERS | nats stream purge ORDERS |
Mark a stream ORDERS as read only | nats stream seal ORDERS |
Add a consumer | nats consumer add |
View a consumer NEW of stream ORDERS | nats consumer info ORDERS NEW |
Remove consumer NEW from stream ORDERS | nats consumer rm ORDERS NEW |
Get messages from consumer NEW of stream ORDERS | nats consumer next ORDERS NEW --ack --count=10 , nats consumer next ORDERS NEW --no-ack , nats consumer sub ORDERS NEW --ack |