The WildFly Operator for Kubernetes provides easy monitoring and configuration for Java applications deployed on WildFly application server using the Source-to-Image (S2I) template for WildFly.
Once installed, the WildFly Operator provides the following features:
-
Create/Destroy: Easily launch an application deployed on WildFly
-
Simple Configuration: Configure the fundamentals of WildFly-based application including number of nodes, application image, etc.
The operator acts on the following Custom Resource Definitions (CRDs):
-
WildFlyServer, which defines a WildFly deployment. TheSpecandStatusof this resources are defined in the API documentation.
The examples require that Minikube is installed and running.
# install WildFlyServer CRD
$ kubectl apply -f deploy/crds/wildfly.org_wildflyservers_crd.yaml
# Install all resources for the WildFly Operator
$ kubectl apply -f deploy/operator.yamlAn example of a custom resource of WildFlyServer is described in quickstart-cr.yaml:
apiVersion: wildfly.org/v1alpha1
kind: WildFlyServer
metadata:
name: quickstart
spec:
applicationImage: "quay.io/wildfly-quickstarts/wildfly-operator-quickstart:18.0"
replicas: 2
storage:
volumeClaimTemplate:
spec:
resources:
requests:
storage: 3Gi|
Note
|
It is based on the S2I application image jmesnil/wildfly-operator-quickstart:18.0 that provides a simple Java Web application wildfly-operator-quickstart on top of WildFly 18.0.0.Final which returns the IP address of its host: $ curl http://localhost:8080/
{"ip":"172.17.0.3"}This simple application illustrates that successive calls will be load balanced across the various pods that runs the application. |
$ kubectl create -f deploy/crds/quickstart-cr.yaml
wildflyserver.wildfly.org/quickstart createdOnce the application is deployed, it can be accessed through a load balancer:
$ curl $(minikube service quickstart-loadbalancer --url)
{"ip":"172.17.0.7"}
$ curl $(minikube service quickstart-loadbalancer --url)
{"ip":"172.17.0.8"}
$ curl $(minikube service quickstart-loadbalancer --url)
{"ip":"172.17.0.7"}As illustrated above, calls to the application are load balanced across the pods that runs the application image (as we can see from the different IP addresses).
The WildFly operator describes the deployed application with $ kubectl describe wildflyserver quickstart:
Name: quickstart
Namespace: default
Labels: <none>
Annotations: <none>
API Version: wildfly.org/v1alpha1
Kind: WildFlyServer
Metadata:
Creation Timestamp: 2019-04-09T08:49:24Z
Generation: 1
Resource Version: 7954
Self Link: /apis/wildfly.org/v1alpha1/namespaces/default/wildflyservers/quickstart
UID: 5feb0fd3-5aa4-11e9-af00-7a65e1e4ff53
Spec:
Application Image: quay.io/wildfly-quickstarts/wildfly-operator-quickstart:18.0
Bootable Jar: false
Replicas: 2
Storage:
Volume Claim Template:
Spec:
Resources:
Requests:
Storage: 3Gi
Status:
Pods:
Name: quickstart-0
Pod IP: 172.17.0.7
Name: quickstart-1
Pod IP: 172.17.0.8
Events: <none>The Status section is updated with the 2 pods names containing the application image.
You can modify this custom resource spec to scale up its replicas from 2 to 3:
$ kubectl edit wildflyserver quickstart
# Change the `replicas: 2` spec to `replicas: 3` and save
wildflyserver.wildfly.org/quickstart editedThe deployment will be updated to scale up to 3 Pods and the resource Status will be updated accordingly:
$ kubectl describe wildflyserver quickstartName: quickstart
Namespace: default
Labels: <none>
Annotations: <none>
API Version: wildfly.org/v1alpha1
Kind: WildFlyServer
Metadata:
Creation Timestamp: 2019-04-09T08:49:24Z
Generation: 2
Resource Version: 8137
Self Link: /apis/wildfly.org/v1alpha1/namespaces/default/wildflyservers/quickstart
UID: 5feb0fd3-5aa4-11e9-af00-7a65e1e4ff53
Spec:
Application Image: quay.io/wildfly-quickstarts/wildfly-operator-quickstart:18.0
Bootable Jar: false
Replicas: 3
Storage:
Volume Claim Template:
Spec:
Resources:
Requests:
Storage: 3Gi
Status:
Pods:
Name: quickstart-0
Pod IP: 172.17.0.7
Name: quickstart-1
Pod IP: 172.17.0.8
Name: quickstart-2
Pod IP: 172.17.0.9
Events: <none>You can then remove this custom resource and its assocated resources:
$ kubectl delete wildflyserver quickstart
wildflyserver.wildfly.org "quickstart" deletedThe examples can also be installed in OpenShift and requires a few additional steps.
The instructions requires that Minishift is installed and running.
Deploying the operator and its resources by executing the following commands:
$ oc login -u system:admin
$ oc adm policy add-cluster-role-to-user cluster-admin developer
$ oc apply -f deploy/crds/wildfly_v1alpha1_wildflyserver_crd.yaml
$ oc apply -f deploy/operator.yaml
$ oc login -u developerAfter installing the WildFlyServer resource from deploy/crds/quickstart-cr.yaml, you have to create a route to expose it from OpenShift:
$ oc expose svc/quickstart-loadbalancer
route.route.openshift.io/quickstart-loadbalancer exposedThis will expose the service from OpenShift. To know the URL of the exposed service, run:
$ oc get route quickstart-loadbalancer --template='{{ .spec.host }}'This will display the host of the route (on my local machine, it displays quickstart-loadbalancer-myproject.192.168.64.16.nip.io).
The application can then be accessed by running:
$ curl "http://$(oc get route quickstart-loadbalancer --template='{{ .spec.host }}')"
{"ip":"172.17.0.9"}-
Add the source under
$GOPATH:$ git clone https://github.com/wildfly/wildfly-operator.git $GOPATH/src/github.com/wildfly/wildfly-operator -
Change to the source directory.
$ cd $GOPATH/src/github.com/wildfly/wildfly-operator -
Review the available build targets.
$ make -
Run any build target. For example, compile and build the WildFly Operator with:
$ make build
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent