Rate limit requests based on peak and off-peak time
You can set the rate limit based on peak or non-peak time by using the Pre-function and the Rate Limiting Advanced plugins together.
This tutorial shows you how to handle traffic with two different Routes: one for peak traffic, and one for off-peak traffic. Then, you apply two plugins:
- The Rate Limiting Advanced plugin applies a different rate limit to each Route.
- The Pre-function plugin runs a Lua function in the rewrite phase, sending traffic to one of these Routes based on the defined peak and off-peak settings in the headers.
Prerequisites
Kong Konnect
This is a Konnect tutorial and requires a Konnect personal access token.
-
Create a new personal access token by opening the Konnect PAT page and selecting Generate Token.
-
Export your token to an environment variable:
export KONNECT_TOKEN='YOUR_KONNECT_PAT'Copied to clipboard! -
Run the quickstart script to automatically provision a Control Plane and Data Plane, and configure your environment:
curl -Ls https://get.konghq.com/quickstart | bash -s -- -k $KONNECT_TOKEN --deck-outputCopied to clipboard!This sets up a Konnect Control Plane named
quickstart, provisions a local Data Plane, and prints out the following environment variable exports:export DECK_KONNECT_TOKEN=$KONNECT_TOKEN export DECK_KONNECT_CONTROL_PLANE_NAME=quickstart export KONNECT_CONTROL_PLANE_URL=https://us.api.konghq.com export KONNECT_PROXY_URL='http://localhost:8000'Copied to clipboard!Copy and paste these into your terminal to configure your session.
Create peak and off-peak Routes
Create a Route to handle peak traffic, and a Route to handle off-peak traffic. We’re going to use headers to distinguish between traffic times.
Attach both Routes to the example-service you created in the prerequisites.
echo '
_format_version: "3.0"
routes:
- name: peak
service:
name: example-service
paths:
- "/anything"
headers:
X-Peak:
- active
- name: off-peak
service:
name: example-service
paths:
- "/anything"
headers:
X-Off-Peak:
- active
' | deck gateway apply -
Apply Rate Limiting Advanced plugin
Apply rate limits to both Routes by enabling the Rate Limiting Advanced plugin on each Route:
echo '
_format_version: "3.0"
plugins:
- name: rate-limiting-advanced
route: peak
config:
limit:
- 10
window_size:
- 30
namespace: peak
- name: rate-limiting-advanced
route: off-peak
config:
limit:
- 5
window_size:
- 30
namespace: off-peak
' | deck gateway apply -
Apply the Pre-function plugin to route peak and off-peak traffic
The Pre-Function plugin lets you run Lua code in a plugin phase of your choosing. In this case, we’re going to write a function that determines the time of day based on the operating system’s time, then sets a request header based on the determined time.
You can set the hours based on your own preferred peak times.
The following command applies the Pre-Function globally and runs it in the rewrite phase:
echo '
_format_version: "3.0"
plugins:
- name: pre-function
config:
rewrite:
- |
local hour = os.date("*t").hour
if hour >= 8 and hour <= 17
then
kong.service.request.set_header("X-Peak","active")
else
kong.service.request.set_header("X-Off-Peak","active")
end
' | deck gateway apply -
Validate
You can now verify that both plugins were configured correctly and are working, by sending more requests than allowed in the configured time limit.
Let’s send 11 requests, which will cover both the off-peak and peak rate limits:
for _ in {1..11}; do
curl -i $KONNECT_PROXY_URL/anything
echo
done
for _ in {1..11}; do
curl -i http://localhost:8000/anything
echo
done
On the last request, you should get a 429 response with the message API rate limit exceeded.
Depending on your OS time, you will see either the X-Peak or X-Off-Peak header in the request,
and you will hit the rate limit at either 6 or 11 requests.
Cleanup
Clean up Konnect environment
If you created a new control plane and want to conserve your free trial credits or avoid unnecessary charges, delete the new control plane used in this tutorial.