Build/Run Helm Manager

Owned by Björn Magnusson
Last updated: Jun 21, 2021
8 min read

Introduction

The helm manager is a service for managing helm charts.  The service provides a REST API for onboarding of charts as well as installation and uninstallation of applications based on these charts.

In addition to the helm manager, a chart repository is used to store the available charts for onboarding and installation.

The Helm manager (and chart repo) can be executed in one of the following deployments:

  • As docker container on a local machine with kubernbetes
  • As kubernetes service and pod on a local machine with kubernetes or in minikube
  • As kubernetes service and pod on a kubernetes cluster

Prerequisites

The following need to be installed, latest version,  on the machine 

  • Kubernetes or minikube including kubectl
  • curl
  • git (if buidling image)
  • maven (if buidling image)
  • docker (for image build and image registry) 
  • helm

Preparation

Clone the nonrtric repo from gerrit and change dir to helm-manager. Make sure to use the correct branch when cloning, use "master" until the branch for D Release is available.

All needed scripts for starting and running the helm manager, in docker or kubernetes are in this directory.

If the Helm Manager shall be installed in a kubernetes cluster the actions below shall be made on a node in cluster.

$ git clone "https://gerrit.o-ran-sc.org/r/nonrtric" -b <branch>

$ cd helm-manager

Build image

There is no need to build the image for the helm manager unless changes are made to the Dockerfile in the current dir.

If no changes are needed, skip this section.

Instruction to build the image, run the command blelow:

$ mvn clean package

The  built image should be named: o-ran-sc/nonrtric-helm-manager:1.0.0-SNAPSHOT. This can be be cah

$ docker images | grep helm

Expected output:

o-ran-sc/nonrtric-helm-manager  1.0.0-SNAPSHOT  56e50ade8c37  3 minutes ago   498MB

Note: Replace the image name in the  docker-hm.sh and helm-manager  if this image shall be used. For the helm-manager.ymal the parameters image and imagePullPolicy shall be configured like this:

    image: o-ran-sc/nonrtric-helm-manager:1.0.0-SNAPSHOT
    imagePullPolicy: Never

Note: Locally built images are not available to a kubernetes cluster unless the image is made available in an image repo accessible from within the cluster.

Create helm chart for test

Create a helm chart for this test. Package the chart into an archive. Run these two commands. The result should be a file named simple-app-0.1.0.tgz.

$ helm create simple-app

$ helm package simple-app


Run in kubernetes

This instruction is valid for running both in a local kubernetes and in a kubernetes ccluster

If running in a local kubernetes, set the env KUBE_HOST to the host of the kubernetes control plane

$ kubectl cluster-info
Kubernetes control plane is running at https://kubernetes.docker.internal:6443
$ KUBE_HOST="kubernetes.docker.internal"

If running in a kubernetes cluster or in minikube, set the env KUBE_HOST to the ip of the kubernetes control plane.

Example
$ kubectl cluster-info
Kubernetes master is running at https://10.2.0.103:6443
$ KUBE_HOST=10.2.0.103

Check if the nonrtric names space exists. If not, create the namespace

$ kubectl get ns nonrtric
$ kubectl create ns nonrtric

Start the chartmuseum service and pod

$ kubectl apply -f kube-cm.yaml

Add the chart, created in the section 'Create helm for test', to the chartmuseum repo. The node port of the chartmuseum service is obtained and env var CM_PORT is assigned that port number.

$ CM_PORT=$(kubectl get svc chartrepo -n nonrtric -o jsonpath='{...ports[?(@.name=="'http'")].nodePort}')
$ curl --data-binary @simple-app-0.1.0.tgz -X POST http://$KUBE_HOST:$CM_PORT/api/charts
{"saved":true}


Create a service account for the helm manager. This example service account bind to the "cluster-admin" role which normally has full permissions to the add/change/read/delete any kubernetes object. It is advisable to bind the service account to a ClusterRole with less permissions if desired.

$ kubectl apply -f helm-manager-sa.yaml
serviceaccount/helm-manager-sa created
clusterrolebinding.rbac.authorization.k8s.io/helm-manager-sa-clusterrolebinding created


Start the helm manager. Four objects will be created. Note that the service is defined as a NodePort. This enables access from outside the cluster and is also a precondition for the test script to work. Change 'type' to 'ClusterIP' in the 'helmmanagerservice' service definition in the file helm-manager.yaml. 

$ kubectl apply -f helm-manager.yaml
service/helmmanagerservice created
pod/helmmanagerservice created
persistentvolume/helm-manager-service-pv created
persistentvolumeclaim/helm-manager-service-pvc created

The chartmuseum repo need to added to helm. This operation must be called with a url accessible from the helm manager pod.

Go into the helm manager container and add the repo.

$ kubectl exec -it helmmanagerservice -n nonrtric -- sh
# helm repo add cm http://chartrepo.nonrtric:8080
"cm" has been added to your repositories
$ exit

The helm manager is now running and configured with a chart repo.

Run the script test.sh to execute the sequence for installing the application 'simpleapp' namespace 'ckhm':

  • Namespace 'ckhm' is created in kubernetes if not existing
  • Onboard chart
  • Install chart
  • Uninstall chart
  • Remove (the onboarded) chart

All operations should report "OK".


$ ./test.sh kube $KUBE_HOST

Example output of the script

Start test
================
Get apps - empty
================
curl -sw %{http_code} http://localhost:32743/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[]}

============
Onboard app
===========
curl -sw %{http_code} http://localhost:32743/helm/charts -X POST -F chart=@simple-app-0.1.0.tgz -F values=@simple-app-values.yaml -F info=<simple-app.json
 Curl OK
  Response: 200
  Body: 

=====================
Get apps - simple-app
=====================
curl -sw %{http_code} http://localhost:32743/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[{"releaseName":"simpleapp","chartName":"simple-app","version":"0.1.0","namespace":"ckhm","repository":"cm"}]}

===========
Install app
===========
curl -sw %{http_code} http://localhost:32743/helm/install -X POST -H Content-Type:application/json -d @simple-app-installation.json
 Curl OK
  Response: 201
  Body: 

=====================
Get apps - simple-app
=====================
curl -sw %{http_code} http://localhost:32743/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[{"releaseName":"simpleapp","chartName":"simple-app","version":"0.1.0","namespace":"ckhm","repository":"cm"}]}

=============================
helm ls to list installed app
=============================
NAME     	NAMESPACE	REVISION	UPDATED                                	STATUS  	CHART           	APP VERSION 
simpleapp	ckhm     	1       	2021-06-01 22:24:12.797624073 +0000 UTC	deployed	simple-app-0.1.0	1.16.0     

==========================================
sleep 30 - give the app some time to start
==========================================
============================
List svc and  pod of the app
============================
NAME                   TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE
simpleapp-simple-app   ClusterIP   10.105.1.129   <none>        80/TCP    30s
NAME                                    READY   STATUS    RESTARTS   AGE
simpleapp-simple-app-858c798f97-k6vsl   1/1     Running   0          30s

========================
Uninstall app simple-app
========================
curl -sw %{http_code} http://localhost:32743/helm/uninstall/simple-app/0.1.0 -X DELETE
 Curl OK
  Response: 204
  Body: 

sleep 10 - give the app some time to remove
=============================================
List svc and  pod of the app - should be gone
=============================================
No resources found in ckhm namespace.
NAME                                    READY   STATUS        RESTARTS   AGE
simpleapp-simple-app-858c798f97-k6vsl   0/1     Terminating   0          41s

=====================
Get apps - simple-app
=====================
curl -sw %{http_code} http://localhost:32743/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[{"releaseName":"simpleapp","chartName":"simple-app","version":"0.1.0","namespace":"ckhm","repository":"cm"}]}

============
Delete chart
===========
curl -sw %{http_code} http://localhost:32743/helm/charts/simple-app/0.1.0 -X DELETE
 Curl OK
  Response: 204
  Body: 

================
Get apps - empty
================
curl -sw %{http_code} http://localhost:32743/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[]}

Test result  All tests ok 
End of test

Cleanup of all created kubernetes object

$ kubectl delete -f helm-manager.yaml
service "helmmanagerservice" deleted
pod "helmmanagerservice" deleted
persistentvolume "helm-manager-service-pv" deleted
persistentvolumeclaim "helm-manager-service-pvc" deleted

$ kubectl delete -f kube-cm.yaml
service "chartrepo" deleted
pod "chartrepo" deleted
persistentvolume "chartrepo-pv" deleted
persistentvolumeclaim "chartrepo-pvc" deleted

$ kubectl delete -f helm-manager-sa.yaml
serviceaccount "helm-manager-sa" deleted
clusterrolebinding.rbac.authorization.k8s.io "helm-manager-sa-clusterrolebinding" deleted


Run in docker with local kubernetes

The helm-manger is possible to run as a docker container. However, a local kubernetes must be running where the application can be installed.

Create a private docker network, unless it already exists,  for the containers to run in.

$ docker network create nonrtric-docker-net

Start the chartmuseum container in a separate window. This will be used as a chart repository. Make note of the port, 8222, which will be available on local host. Charts uploaded to the chartmuseum container will be availed in the mounted dir 'charts' on your host.

$ ./docker-cm.sh
docker-cm.sh 
docker run \
	--rm \
	-it \
    -p 8222:8080 \
    --name chartmuseum \
    --network nonrtric-docker-net \
    -e DEBUG=1 \
    -e STORAGE=local \
    -e STORAGE_LOCAL_ROOTDIR=/charts \
    -v $(pwd)/charts:/charts \
    ghcr.io/helm/chartmuseum:v0.13.1

Add the chart, created in the section 'Create helm for test', to the repo

$ curl --data-binary "@simple-app-0.1.0.tgz" -X POST http://localhost:8222/api/charts
{"saved":true}


Start the helm manager in a separate window. Make note of the port, 8112, which will be available on local host. This is the port to the Helm manager REST API.

$ ./docker-hm.sh
docker-hm.sh 
docker run \
    --rm  \
    -it \
    -p 8112:8083  \
    --name helmmanagerservice \
    --network nonrtric-docker-net \
    -v $(pwd)/mnt/database:/var/helm-manager/database \
    -v ~/.kube:/root/.kube \
    -v ~/.helm:/root/.helm \
    -v ~/.config/helm:/root/.config/helm \
    -v ~/.cache/helm:/root/.cache/helm \
    -v $(pwd)/config/KubernetesParticipantConfig.json:/opt/app/helm-manager/src/main/resources/config/KubernetesParticipantConfig.json \
    -v $(pwd)/config/application.yaml:/opt/app/helm-manager/src/main/resources/config/application.yaml \
    nexus3.o-ran-sc.org:10004/o-ran-sc/nonrtric-helm-manager:1.0.0-SNAPSHOT

The chartmusem repo need to added to helm. This operation must be called with a url accessible from the helm manager container.

Go into the helm manager container and add the repo.

$ docker exec -it helmmanagerservice sh
# helm repo add cm http://chartmuseum:8080
"cm" has been added to your repositories
$ exit


The helm manager is now running and configured with a chart repo.

Run the script test.sh to execute the sequence for installing the application 'simpleapp' namespace 'ckhm':

  • Namespace 'ckhm' is created in kubernetes if not existing
  • Onboard chart
  • Install chart
  • Uninstall chart
  • Remove (the onboarded) chart

All operations should report "OK".

$ ./test.sh docker

Expected oputput:

Start test
================
Get apps - empty
================
curl -sw %{http_code} http://localhost:8112/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[]}

============
Onboard app
===========
curl -sw %{http_code} http://localhost:8112/helm/charts -X POST -F chart=@simple-app-0.1.0.tgz -F values=@simple-app-values.yaml -F info=<simple-app.json
 Curl OK
  Response: 200
  Body: 

=====================
Get apps - simple-app
=====================
curl -sw %{http_code} http://localhost:8112/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[{"releaseName":"simpleapp","chartName":"simple-app","version":"0.1.0","namespace":"ckhm","repository":"cm"}]}

===========
Install app
===========
curl -sw %{http_code} http://localhost:8112/helm/install -X POST -H Content-Type:application/json -d @simple-app-installation.json
 Curl OK
  Response: 201
  Body: 

=====================
Get apps - simple-app
=====================
curl -sw %{http_code} http://localhost:8112/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[{"releaseName":"simpleapp","chartName":"simple-app","version":"0.1.0","namespace":"ckhm","repository":"cm"}]}

=============================
helm ls to list installed app
=============================
NAME     	NAMESPACE	REVISION	UPDATED                                	STATUS  	CHART           	APP VERSIO 
simpleapp	ckhm     	1       	2021-06-01 16:31:30.255849815 +0000 UTC	deployed	simple-app-0.1.0	1.16.0     

==========================================
sleep 30 - give the app some time to start
==========================================
============================
List svc and  pod of the app
============================
NAME                   TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
simpleapp-simple-app   ClusterIP   10.102.209.44   <none>        80/TCP    31s
NAME                                    READY   STATUS    RESTARTS   AGE
simpleapp-simple-app-858c798f97-vm6hd   1/1     Running   0          31s

========================
Uninstall app simple-app
========================
curl -sw %{http_code} http://localhost:8112/helm/uninstall/simple-app/0.1.0 -X DELETE
 Curl OK
  Response: 204
  Body: 

sleep 10 - give the app some time to remove
=============================================
List svc and  pod of the app - should be gone
=============================================
No resources found in ckhm namespace.
No resources found in ckhm namespace.

=====================
Get apps - simple-app
=====================
curl -sw %{http_code} http://localhost:8112/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[{"releaseName":"simpleapp","chartName":"simple-app","version":"0.1.0","namespace":"ckhm","repository":"cm"}]}

============
Delete chart
===========
curl -sw %{http_code} http://localhost:8112/helm/charts/simple-app/0.1.0 -X DELETE
 Curl OK
  Response: 204
  Body: 

================
Get apps - empty
================
curl -sw %{http_code} http://localhost:8112/helm/charts
 Curl OK
  Response: 200
  Body: {"charts":[]}

Test result  All tests ok 
End of test