Shell Script to simulate API requests for Load Tests

You can use below shell script to simulate a pre-defined load on an API.

       
#!/bin/bash

#########################################################
# This is simple shell script to simulate API load      #
# for given duration                                    #
# Eg: DURATION=60 and TPS=20, This script will trigger  #
# 20 requests per second for 1 minute.                  #
#########################################################


#define variables

set -x # run in debug mode
DURATION=60 # how long should load be applied ? - in seconds
TPS=20 # number of requests per second
end=$((SECONDS+$DURATION))

#start load
while [ $SECONDS -lt $end ];
do
    for ((i=1;i<=$TPS;i++)); do
        curl -X POST  -H 'Accept: application/json' -H 'Authorization: Bearer xxxxxxxxxxxxx' -H 'Content-Type: application/json' -d '{}' --cacert /path/to/cert/cert.crt -o /dev/null -s -w '%{time_starttransfer}\n' >> response-times.log &
    done
    sleep 1
done
wait

#end load
echo "Load test has been completed" 
       

Download the script from here.

Here while loop is to run this load for given time period
for loop is to fire given number of requests per second
cacert is optional - only used for https request, you can use -k option as well
-o /dev/null is to write the output to empty
-s is to silence the process
-w '%{timestarttransfer}%' is to retrieve the response time. This time will be written to a file
this request will run in background and script will initiate next request.