Modified version of Henrik Bengtsson's speedtest-cli code which will dispatch the test results to the IFTTT Maker Channel.

speedtest-ifttt.sh

#!/usr/bin/env bash
###########################################################################
# Originally written by: Henrik Bengtsson, 2014
# https://github.com/HenrikBengtsson/speedtest-cli-extras
# Modified to use IFTTT by: Alasdair Allan, 2015
# License: GPL (>= 2.1) [http://www.gnu.org/licenses/gpl.html]
###########################################################################

# Character for separating values
# (commas are not safe, because some servers return speeds with commas)
sep=";"

# Temporary file holding speedtest-cli output
user=$USER
if test -z $user; then
  user=$USERNAME
fi
log=/tmp/$user/speedtest-csv.log

# Local functions
function str_extract() {
 pattern=$1
 # Extract
 res=`grep "$pattern" $log | sed "s/$pattern//g"`
 # Drop trailing ...
 res=`echo $res | sed 's/[.][.][.]//g'`
 # Trim
 res=`echo $res | sed 's/^ *//g' | sed 's/ *$//g'`
 echo $res
}

# Display header?
if test "$1" = "--header"; then
  start="start"
  stop="stop"
  from="from"
  from_ip="from_ip"
  server="server"
  server_dist="server_dist"
  server_ping="server_ping"
  download="download"
  upload="upload"
  share_url="share_url"
else
  mkdir -p `dirname $log`

  start=`date +"%Y-%m-%d %H:%M:%S"`

  if test -n "$SPEEDTEST_CSV_SKIP" && test -f "$log"; then
    # Reuse existing results (useful for debugging)
    1>&2 echo "** Reusing existing results: $log"
  else
    # Query Speedtest
    /usr/local/bin/speedtest-cli --share > $log
  fi
  
  stop=`date +"%Y-%m-%d %H:%M:%S"`
  
  # Parse
  from=`str_extract "Testing from "`
  from_ip=`echo $from | sed 's/.*(//g' | sed 's/).*//g'`
  from=`echo $from | sed 's/ (.*//g'`
  
  server=`str_extract "Hosted by "`
  server_ping=`echo $server | sed 's/.*: //g'`
  server=`echo $server | sed 's/: .*//g'`
  server_dist=`echo $server | sed 's/.*\\[//g' | sed 's/\\].*//g'`
  server=`echo $server | sed 's/ \\[.*//g'`
  
  download=`str_extract "Download: "`
  upload=`str_extract "Upload: "`
  share_url=`str_extract "Share results: "`
fi

# Standardize units?
if test "$1" = "--standardize"; then
  download=`echo $download | sed 's/Mbits/Mbit/'`
  upload=`echo $upload | sed 's/Mbits/Mbit/'`
fi

# Send to IFTTT
secret_key="SECRET_KEY"
value1=`echo $server_ping | cut -d" " -f1`
value2=`echo $download | cut -d" " -f1`
value3=`echo $upload | cut -d" " -f1` 
json="{\"value1\":\"${value1}\",\"value2\":\"${value2}\",\"value3\":\"${value3}\"}"
curl -X POST -H "Content-Type: application/json" -d "${json}" https://maker.ifttt.com/trigger/speedtest/with/key/${secret_key}  

Everything was working great. On the sudden the script started filling it into a new spreadsheet speedtest(1) .... not sure where the copy came from and why its just posting it in there.

Google Sheets have a maximum number of rows. Once you exceed that number it will auto-magically generate a new sheet.

This has been working great since I started using it over a year ago, but it looks like something has changed on the IFTTT platform. The recipe, and my applet, both 404 now. It looks like it stopped working on March 8, 2021 around 2 PM CST. I'm wondering if anyone has found a workaround?

@JeremyDurnell Ran into the same issue on the same date but only noticed now. I found that IFTTT was not at fault as the webhook and the speadsheet update commands had not changed.

The issue I found was due to an update on the speedtest side which was failing due to some server changes. The error I receive when running the command manually is:
ValueError: invalid literal for int() with base 10

There are 2 solutions I have found.

1. Setup your speed tests from scratch with the updated configs (not from aallan at the time of this post)

2. Modify the speedtest.py file manually by;
   Open up speedtest.py file (Mine was located: /usr/local/lib/python2.7/dist-packages/speedtest.py)
   Head to line 1174
   Comment it out and replace with the new line from the below article:
   sivel/speedtest-cli@6e9a667

Hopefully this helps you or the next person that runs into this

Hey! What IFTTT applets are you using? I can't find "speedtest" nor "Log Speedtest results to Spreadsheet"...