tomcat-openshift

Example to use tomcat docker image in openshift
First look to https://github.com/apache/tomcat/tree/main/modules/stuffed For multi-plaform add :platform like jfclere/tomcat-demo:aarch64 to the docker URL. The tomcat-openshift is just explaining how to use the image in OpenShift and demo it.

mvn install  
podman build -t quay.io/jfclere/tomcat10.1-demo .  
podman push quay.io/jfclere/tomcat10.1-demo  

To test the tomcat-demo localy (java.net.UnknownHostException: tomcat-demo: Name does not resolve is expected):

podman run --rm -p 8080:8080 --env "KUBERNETES_NAMESPACE=tomcat-demo" -it quay.io/jfclere/tomcat10.1-demo  

Testing using an imagestream

kubectl create -f tomcat-imagestream.yaml
kubectl create -f tomcat-app-is.yaml

Testing a new build after pushing the image with podam do:

oc import-image tomcat --confirm --all

connect to openshift using DNSPing

oc new-project tomcat-demo
oc process -f deployment.yaml KUBERNETES_NAMESPACE=`oc project -q` DOCKER_URL=quay.io/jfclere/tomcat10.1-demo | oc create -f -
oc create -f service.yaml  
oc scale --replicas=2 deployment tomcat-demo  
oc create -f route.yaml  

Read the URL for demo:

[jfclere@localhost tomcat-openshift]$ oc get routes
NAME          HOST/PORT                                                             PATH      SERVICES      PORT      TERMINATION   WILDCARD
tomcat-demo   tomcat-demo-tomcat-demo.apps.us-east-1.online-starter.openshift.com             tomcat-demo   http                    None

connect to openshift using KUBEPing: (you need to have the permission to create the serviceaccount)

Change in conf/server.xml DNSMembershipProvide to KubernetesMembershipProvider and rebuild the Docker image:

podman build -t quay.io/jfclere/tomcat-demo10.1 .  
podman push quay.io/jfclere/tomcat-demo10.1  

Create the service account:

oc new-project tomcat-demo
oc policy add-role-to-user view system:serviceaccount:tomcat-demo:default -n tomcat-demo  

Then it is like DNSPing:

oc process -f deployment.yaml KUBERNETES_NAMESPACE=`oc project -q` DOCKER_URL=quay.io/jfclere/tomcat10.1-demo | oc create -f -
oc create -f service.yaml  
oc scale --replicas=2 deployment tomcat-demo  
oc create -f route.yaml  

Using kubernetes

kubectl create namespace tomcat-demo
kubectl config set-context --current --namespace=tomcat-demo
kubectl create -f kube-tomcat-demo.yaml
kubectl create -f service.yaml
kubectl expose deployment tomcat-demo --type=LoadBalancer --name=tomcat-balancer

Note:

root@pc-12 tomcat-openshift]# kubectl get svc
NAME              TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
tomcat-balancer   LoadBalancer   10.100.57.140   <pending>     8080:32567/TCP   4m6s
tomcat-demo       ClusterIP      None            <none>        80/TCP           31m

<pending> is NORMAL, use curl (or browser to port 32567) to test.

Quick demo

The demo assumes that you have a running cluster and registry for the images and the corresponding $HOME/.kube/config and httpd with mod_proxy_balancer runing on the box. It assumes the following boxes, jfcportal for the registry, master for the controlplane and greeen and blue for the nodes.

bash startdemo.sh

Wait until the services are created.

[root@pc-79 tomcat-openshift]# kubectl get svc
NAME              TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
tomcat-balancer   LoadBalancer   10.99.220.176   <pending>     8080:31533/TCP   4m16s
tomcat-demo       ClusterIP      None            <none>        80/TCP           4m17s

Then configure and restart httpd with the port in the /etc/httpd/conf/proxy.conf file:

bash startbrower.sh

Use a browser with json viewer on the box...

Registry

The registry is just a docker image running in a box the nodes and controlplane are able to access:

docker run -d -p 5000:5000 --restart=always --name registry registry:2

And push the tomcat-demo image there, otherwise change the jfcportal:5000/tomcat-demo:2.2 to something like docker.io/jfclere/tomcat-demo