Optional DRU support

The optional ZOO-Kernel DRU support gives you the opportunity to use OGC API - Processes - Part 2: Deploy, Replace, Undeploy draft specificatoin. It means that your server will provide new end-points to setup a new process, update an existing one, or delete a deployed (mutable) process.

The DRU support is designed to perform the processing function on a Kubernetes cluster using the Calrissian, a Common Workflow Language runner for Kubernetes. Calrissian uses CWL, an open standard defining Command Line Tools and Workflow classes, over Kubernetes that enables the implementation of each step in a workflow as a container. It provides simple, flexible mechanisms for specifying constraints between the steps in a workflow and artifact management for linking the output of any step as an input to subsequent steps.

Installation on a Minikube Cluster

Follow the steps described below in order to activate the ZOO-Project optional DRU support.

Be sure you have all the prerequisistes setup before starting the installation.

For deploying the ZOO-Project for developing and testing purposes (e.g. on local machine), please proceed to the section Installation on a Minikube Cluster.

For building the ZOO-Project docker image using the project source code, please proceed to the section Building the docker image (for developper).

Prerequisites

Installation on a Minikube Cluster

ZOO-Project DRU Helm chart

The current helm chart is available from here: https://github.com/ZOO-Project/charts.git. You will need to clone this repository and make the following modifications to it.

git clone https://github.com/ZOO-Project/charts.git
Create a dedicated namespace for the ZOO-Project

This namespace will be reserved for the operation of the ZOO-Project in order to separate the ZOO-Project proper execution from its processings job on Kubernetes.

For instance, let’s create a zoo-project-dru namespace.

kubectl create ns zoo
Deploy using Helm

The ZOO-Project with DRU support is setup via helm specifying an optional “release name”.

For instance, we will install the ZOO-Project with the name zoo-project-dru.

helm upgrade --install zoo-project-dru zoo-project-dru -f zoo-project-dru/values_minikube.yaml -n zoo

Release "zoo-project-dru" does not exist. Installing it now.
NAME: zoo-project-dru
LAST DEPLOYED: Wed Jan 24 09:52:52 2024
NAMESPACE: zoo
STATUS: deployed
REVISION: 1
NOTES:
1. Get the application URL by running these commands:
  export POD_WS_NAME=$(kubectl get pods --namespace zoo -l "app.kubernetes.io/name=zoo-project-dru-websocketd,app.kubernetes.io/instance=zoo-project-dru-websocketd" -o jsonpath="{.items[0].metadata.name}")
  export CONTAINER_WS_PORT=$(kubectl get pod --namespace zoo $POD_WS_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
  echo "Visit ws://127.0.0.1:8888 to use your application"
  kubectl --namespace zoo port-forward $POD_WS_NAME 8888:$CONTAINER_WS_PORT &
  export POD_NAME=$(kubectl get pods --namespace zoo -l "app.kubernetes.io/name=zoo-project-dru,app.kubernetes.io/instance=zoo-project-dru" -o jsonpath="{.items[0].metadata.name}")
  export CONTAINER_PORT=$(kubectl get pod --namespace zoo $POD_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
  echo "Visit http://127.0.0.1:8080 to use your application"
  kubectl --namespace zoo port-forward $POD_NAME 8080:$CONTAINER_PORT

Note

💡 detailed information of all the chart parameter is available in the chart README

Check that service is available

kubectl get service zoo-project-dru-service --namespace zoo

Should return something like:

NAME                      TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
zoo-project-dru-service   ClusterIP   10.104.248.111   <none>        80/TCP    8m

Get the application URL by running these commands:

export POD_WS_NAME=$(kubectl get pods --namespace zoo -l "app.kubernetes.io/name=zoo-project-dru-websocketd,app.kubernetes.io/instance=zoo-project-dru-websocketd" -o jsonpath="{.items[0].metadata.name}")
export CONTAINER_WS_PORT=$(kubectl get pod --namespace zoo $POD_WS_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
echo "Visit ws://127.0.0.1:8888 to use your application"
kubectl --namespace zoo port-forward $POD_WS_NAME 8888:$CONTAINER_WS_PORT &
export POD_NAME=$(kubectl get pods --namespace zoo -l "app.kubernetes.io/name=zoo-project-dru,app.kubernetes.io/instance=zoo-project-dru" -o jsonpath="{.items[0].metadata.name}")
export CONTAINER_PORT=$(kubectl get pod --namespace zoo $POD_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
echo "Visit http://127.0.0.1:8080 to use your application"
kubectl --namespace zoo port-forward $POD_NAME 8080:$CONTAINER_PORT

At this step, the ZOO-Project-DRU deployment using helm chart should be accesible from this address: http://127.0.0.1:8080/ogc-api/api.html.

Remove ZOO-Project-DRU from Minikube

In case you want to remove the ZOO-Project-DRU from your Minikube, you can use the commands bellow.

helm uninstall zoo-project-dru -n zoo && \
kubectl delete pvc data-zoo-project-dru-postgresql-0 \
                   data-zoo-project-dru-rabbitmq-0 \
                   redis-data-zoo-project-dru-redis-master-0\
                   redis-data-zoo-project-dru-redis-replicas-0\
                   -n zoo
Building the docker image (for developper)

For a developper it may be convenient to test a new functionality on Minikube. To do so, use the following commands to build a dedicated ZOO-Project (with DRU support enabled) binary image to be used to deploy using helm.

In case you have modified the ZOO-Project source code and want to test it on your Minikube, you can then update the Dockerfile to use a modified copy of the ZOO-Project located in the ZPGIT directory by commenting line 83 and uncommenting line 84.

eval $(minikube docker-env)
docker build . -t zoo-project/zoo-project-dru:myversion-X.Y.Z

To ensure that helm will use this specific image during the deployment, you can change the following values from the zoo-project-dru/values.yaml file.

Replace the following (for both zookernel and zoofpm):

pullPolicy: IfNotPresent

By:

pullPolicy: Never

Also, make sure to update the tag for both zoofpm and zookernel images to the one defined during the docker build command used to build the docker image locally.

Now you can deploy on Minikube as defined here: Deploy using Helm