Knative CLI Demo On OpenShift 4.11

Requirements:

  • install the kn cli

Install kn cli on linux 

wget https://mirror.openshift.com/pub/openshift-v4/clients/serverless/latest/kn-linux-amd64.tar.gz
tar -zxvf kn-linux-amd64.tar.gz
chmod +x kn-linux-amd64 
sudo mv kn-linux-amd64  /usr/local/bin/kn
kn version

Using Knative Client

Login to OpenShift

oc login --token=CHANGEME --server=https://api.example.com:6443

Create new project

oc new-project serverless-demo

Verify namespace

kn service list --namespace serverless-demo

Create deployment

kn service create echo --image tcij1013/echo:latest

Reterive URL

TESTURL=$(kn service list | grep echo | awk '{print $2}')

Test URL or open in web browser

echo $TESTURL
curl -s $TESTURL

Configure concurrency limits on deployment

Concurrency is nothing more than the number of requests a system can service at any given time and is normally driven by a fixed resource such as CPU.

kn service update echo --concurrency-limit=1

Send traffic to deployment

while true; do sleep 1; curl $TESTURL; echo -e '\n\n\n\n'$(date) hit CTRL-c to stop;done

Change concurrency limit back to zero

kn service update echo --concurrency-limit=0

Set a deployment revision

kn service update echo --revision-name echo-v1
curl -s  $TESTURL

Pass new message to v2 deployment

kn service update echo --revision-name echo-v2 --env MSG="OCP KNATIVE DEMO"
curl -s $TESTURL

Add weight to traffic to spread it between v1 and v2

kn service update echo --traffic echo-v1=50,echo-v2=50
while true; do sleep 1; curl $TESTURL; echo -e '\n\n\n\n'$(date) hit CTRL-c to stop;done

Setup a deployment with a v3 revision see that traffic does not gt sent to this deployment

kn service update echo --revision-name echo-v3 --env MSG="Having fun?"
while true; do sleep 1; curl $TESTURL; echo -e '\n\n\n\n'$(date) hit CTRL-c to stop;done

Delete deployment

kn service delete echo

Links: Knative Tutorial Knative CLI (kn) for use with OpenShift Serverless