Deploying an Application Through the Helm v2 Client

Prerequisites

Installing Helm v2

1. Download the Helm client from the VM connected to the cluster.

   wget https://get.helm.sh/helm-v2.17.0-linux-amd64.tar.gz
   
   

2. Decompress the Helm package.

   tar -xzvf helm-v2.17.0-linux-amd64.tar.gz
   
   

3. Copy Helm to the system path, for example, /usr/local/bin/helm.

   mv linux-amd64/helm /usr/local/bin/helm
   
   

4. RBAC is enabled on the Kubernetes API server. Create the service account name tiller for the tiller and assign cluster-admin, a system ClusterRole, to the tiller. Create a tiller resource account as follows:

   vim tiller-rbac.yaml
   
   

   File content:

   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: tiller
     namespace: kube-system
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: ClusterRoleBinding
   metadata:
     name: tiller
   roleRef:
     apiGroup: rbac.authorization.k8s.io
     kind: ClusterRole
     name: cluster-admin
   subjects:
     - kind: ServiceAccount
       name: tiller
       namespace: kube-system
   
   

5. Deploy the tiller resource account.

   kubectl apply -f tiller-rbac.yaml
   
   

6. Initialize the Helm and deploy the pod of tiller.

   helm init --service-account tiller --skip-refresh
   
   

7. Query the status.

   kubectl get pod -n kube-system -l app=helm
   
   

   Command output:

   NAME                             READY   STATUS    RESTARTS   AGE
   tiller-deploy-7b56c8dfb7-fxk5g   1/1     Running   1          23h
   
   

8. Query the Helm version.

   helm version
   
   

   Command output:

   Client: &version.Version{SemVer:"v2.17.0", GitCommit:"a690bad98af45b015bd3da1a41f6218b1a451dbe", GitTreeState:"clean"}
   Server: &version.Version{SemVer:"v2.17.0", GitCommit:"a690bad98af45b015bd3da1a41f6218b1a451dbe", GitTreeState:"clean"}
   
   

Installing the Helm Chart

You can obtain the required chart in the stable directory at https://github.com/helm/charts, download the chart, and upload it to the node.

1. Download and decompress the obtained chart. Generally, the chart is in ZIP format.

   unzip chart.zip
   
   

2. Install the Helm chart.

   helm install aerospike/
   
   

3. After the installation is complete, run the helm list command to check the status of the chart releases.

Common Issues

• The following error message is displayed after the Helm version command is executed:

  Client:
  &version.Version{SemVer:"v2.17.0",
  GitCommit:"a690bad98af45b015bd3da1a41f6218b1a451dbe", GitTreeState:"clean"}
  E0718 11:46:10.132102    7023 portforward.go:332] an error occurred
  forwarding 41458 -> 44134: error forwarding port 44134 to pod
  d566b78f997eea6c4b1c0322b34ce8052c6c2001e8edff243647748464cd7919, uid : unable
  to do port forwarding: socat not found.
  Error: cannot connect to Tiller
  
  

  The preceding information is displayed because the socat is not installed. Run the following command to install the socat:

  yum install socat -y
  
  

• Socat has been installed. When you check the Helm version, the error message "Error: cannot connect to Tiller" is displayed.

  helm version
  
  

  Error information:

  Client: &version.Version{SemVer:"v3.3.0", GitCommit:"021cb0ac1a1b2f888144ef5a67b8dab6c2d45be6", GitTreeState:"clean"}
  Error: cannot connect to Tiller
  
  

  The Helm chart reads the configuration certificate in .Kube/config and communicates with Kubernetes. The preceding error indicates that the kubectl configuration is incorrect. In this case, reconnect the cluster to kubectl. For details, see Procedure.

• Storage fails to be created after you have connected to cloud storage services.

  This issue may be caused by the annotation field in the created PVC. Change the chart name and install the chart again.

• If kubectl is not properly configured, the error message "Error: Kubernetes cluster unreachable..." will be displayed when you install Helm.

  Example:

  helm install prometheus/ --generate-name
  
  

  Error information:

  WARNING: This chart is deprecated
  Error: Kubernetes cluster unreachable: Get "http://localhost:8080/version?timeout=32s": dial tcp [::1]:8080: connect: connection refused
  
  

  Solution: Configure kubeconfig for the node. For details, see Procedure.