Script to test latency and speed towards OpenShift Kubernetes API Server

check-api-latency-and-speed.sh

# If $USERNAME and $PASSWORD are not defined
# in the environment prompt for them
if [ -z "${USERNAME+x}" ]; then
    read -p 'Username: ' USERNAME
fi
if [ -z "${PASSWORD+x}" ]; then
    read -sp 'Password: ' PASSWORD
fi

echo -e "\nAttempting to find the K8s API Server and token"
# K8s server API
K8S_API=$( oc whoami --show-server )
# Try to get token from  
TOKEN=$( oc whoami --show-token )

# If using kubeadmin default cert authentication we need differnet way to obtain token
if [ $TOKEN == ""]; then
    echo "Obtaining token by authentication instead"
    # Identify API endpoint for the OAUTH authorization server
    AUTH_ENDPOINT=$( oc get --raw '/.well-known/oauth-authorization-server' | jq -r .authorization_endpoint )
    # Do user/pass authentication to obtain token
    URL_WTOKEN=$( curl -ks -u $USERNAME:$PASSWORD -o /dev/null -w "%{redirect_url}\n" "$AUTH_ENDPOINT?client_id=openshift-challenging-client&response_type=token" )
    # extract token from URL
    TOKEN=$( echo $URL_WTOKEN | sed "s/^.*access_token=//" | sed "s/&.*//" )
fi

for a in {1..100}; do 
    # endpoint to test -- Update as needed
    TEST_ENDPOINT="$K8S_API/api/v1/nodes"
    #
    curl -k -H "Authorization: Bearer $TOKEN" -so /dev/null \
    -w "HTTP:%{http_code}  DNS:%{time_namelookup}s  CONNECT:%{time_connect}s  START:%{time_starttransfer}s  TOTAL:%{time_total}s  SPEED:%{speed_download}Bps\n" \
    "$TEST_ENDPOINT";
sleep 1 ; done

Hi, this script looks good. Excuse the question, but how do I interpret the following result:

HTTP:200 DNS:0.002376s CONNECT:0.003067s START:1.210093s TOTAL:1.218507s SPEED:314605.000Bps

I know that HTTP: 200 is fine. This protocol is up but the others I do not know how to interpret. I mean, what I understand is that from my notebook it makes queries but DNS, CONNECT, START, TOTAL and SPEED through the apiserver service. Thanks in advance.

The results are like this: <http-code>,<how long it took to do the dns resolution>,<how long it took to establish the connection>,<after the connection was stablished when it started the transfer>,<total time to complete transfer>,<speed in Bps experience during the transfer>

For more details refer to the variables available for the -w of the curl command in the man page https://curl.se/docs/manpage.html

Amazing! Thanks a lot for you answer.