LLO K8s

Introduction

K8s Operator developed using the Operator SDK toolkit for Infrastructure Elements that use Kubernetes as its container management framework.

Features

This project aims to follow the Kubernetes Operator pattern. It uses Controllers, which provide a reconcile function responsible for synchronizing resources until the desired state is reached on the cluster. More information can be found via the Kubebuilder Documentation.

The LLO K8s Operator watches for a new ServiceComponentK8s (K8s Custom Resource) deployment in the K8s cluster and then deploys a K8s Deployment and a linked service in the same K8s cluster. When the ServiceComponentK8s is deleted, all the created K8s resources are also deleted.

This operator also updates the status attribute of the ServiceComponent entity in Orion-LD to be compliant with the aerOS lifecycle management of deployed services in the continuum.

User guide

Deploy a K8s Custom Resource of kind ServiceComponentK8s in your K8s cluster:

kubectl apply -f your-sck8s-cr.yaml

This is an example of a ServiceComponentK8s:

apiVersion: llo.aeros-project.eu/v1alpha1
kind: ServiceComponentK8s
metadata:
  labels:
    app.kubernetes.io/name: component-1-of-the-service-1
    app.kubernetes.io/instance: urn_ngsi-ld_Service_1_Component_1
    app.kubernetes.io/part-of: urn_ngsi-ld_Service_1
    app.kubernetes.io/managed-by: aeros-project.eu
    app.kubernetes.io/created-by: urn_ngsi-ld_LowLevelOrchestrator_2
  name: service-1-orion-ld
spec:
  selectedIE: urn:ngsi-ld:InfrastructureElement:continuum-cluster-worker-2
  image: fiware/orion-ld:1.5.1
  ports:
    - number: 1026
      protocol: TCP
  cliArgs:
    - key: -brokerId
      value: test-broker
    - key: -dbhost
      value: service-1-mongo
    - key: -t
      value: 0-255
    - key: -logLevel
      value: DEBUG
    - key: -forwarding
    - key: -experimental
    - key: -wip
      value: entityMaps

To delete the previously created ServiceComponentK8s in the K8s cluster:

kubectl delete -f your-sck8s-cr.yaml

Prerequisities

A K8s cluster is required. The controller will automatically use the current context in your kubeconfig file (i.e. whatever cluster kubectl cluster-info shows).

Installation

All the needed K8s manifests have been packaged into a single YAML file, which is available in the repository.

kubectl apply -f operator-deployment.yaml

You can also create these manifests by running the below command, but some modifications may be needed.

kustomize build config/default > operator-deployment.yaml

This file has also been uploaded to the Common deployments repository. Therefore, you can install it just by running:

curl --header "PRIVATE-TOKEN: <token-from-common-deployments>" https://gitlab.aeros-project.eu/api/v4/projects/65/packages/generic/llo/1.0.1/k8s-operator-sdk-deployment.yaml | kubectl apply -f -

Developer guide

As previously mentioned, this K8s Operator has been developed using the Go-based Operator of the Operator SDK framework. Please, check the official documentation for more information.

Warning

  • The golang version must be 1.21

  • The K8s cluster that is configured as the current context in the kubeconfig file must be reachable

Install the Operator SDK CLI

The official installation guide is available here, but a quick installation guide is included here.

  • Set platform information as environment variables:

export ARCH=$(case $(uname -m) in x86_64) echo -n amd64 ;; aarch64) echo -n arm64 ;; *) echo -n $(uname -m) ;; esac)
export OS=$(uname | awk '{print tolower($0)}')

  • Download the binary for your platform from the Github releases. The latest version is 1.35.0:

export OPERATOR_SDK_VERSION=v1.35.0
export OPERATOR_SDK_DL_URL=https://github.com/operator-framework/operator-sdk/releases/download/${OPERATOR_SDK_VERSION}
curl -LO ${OPERATOR_SDK_DL_URL}/operator-sdk_${OS}_${ARCH}

  • Install the downloaded release binary in the PATH:

chmod +x operator-sdk_${OS}_${ARCH} && sudo mv operator-sdk_${OS}_${ARCH} /usr/local/bin/operator-sdk

Note

Run make –help for more information on all potential make targets

Run the Operator

  1. Generate CRDs and other needed manifests

make manifests

  1. Generate internal operator-sdk code

make generate

  1. Install the CRDs into the cluster:

make install

  1. Run the controller (this will run in the foreground, so switch to a new terminal if you want to leave it running):

make run

Note

You can also run this in one step by running: make install run

  1. Install example Instances of Custom Resources:

kubectl apply -f config/samples/

Generate and upload the Docker image

  1. Build and push your image to the location specified by IMG:

make docker-build docker-push IMG=<some-registry>/aeros-llo-k8s-operator-sdk:tag

To upload the image to the common deployments repo (Docker login is required):

make docker-build docker-push IMG=registry.gitlab.aeros-project.eu/aeros-public/common-deployments/llo/k8s-operator-sdk:1.0.1-mvp

  1. Deploy the controller to the cluster with the image specified by IMG:

make deploy IMG=<some-registry>/aeros-llo-k8s-operator-sdk:tag

To deploy the image to the common deployments repo (Docker login is required):

make deploy IMG=registry.gitlab.aeros-project.eu/aeros-public/common-deployments/llo/k8s-operator-sdk:1.0.1-mvp

Uninstall the Operator

First, undeploy the controller from the cluster:

make undeploy

Then, delete the CRDs from the cluster:

make uninstall

Authors

Universitat Politècnica de València