3engines_doc/docs/kubernetes/How-To-Access-Kubernetes-Cluster-Post-Deployment-Using-Kubectl-On-connectVM-Cloud-connectVM-Magnum.html.md

How To Access Kubernetes Cluster Post Deployment Using Kubectl On connectVM Cloud connectVM Magnum[🔗](#how-to-access-kubernetes-cluster-post-deployment-using-kubectl-on-brand-name-connectVM-magnum "Permalink to this headline")
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In this tutorial, you start with a freshly installed Kubernetes cluster on connectVM connectVM server and connect the main Kubernetes tool, **kubectl** to the cloud.

What We Are Going To Cover[🔗](#what-we-are-going-to-cover "Permalink to this headline")
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> * How to connect **kubectl** to the connectVM Magnum server
> * How to access clusters with **kubectl**

Prerequisites[🔗](#prerequisites "Permalink to this headline")
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No. 1 **Hosting**

You need a connectVM Cloud hosting account with Horizon interface <https://console.connectvm.com/>.

No. 2 **Installation of kubectl**

Standard types of **kubectl** installation are described on [Install Tools page](https://kubernetes.io/docs/tasks/tools/) of the official Kubernetes site.

No. 3 **A cluster already installed on Magnum site**

You may already have a cluster installed if you have followed one of these articles:

> * With Horizon interface: [How to Create a Kubernetes Cluster Using connectVM Cloud connectVM Magnum](How-to-Create-a-Kubernetes-Cluster-Using-connectVM-Cloud-connectVM-Magnum.html.md).
> * With command line interface: [How To Use Command Line Interface for Kubernetes Clusters On connectVM Cloud connectVM Magnum](How-To-Use-Command-Line-Interface-for-Kubernetes-Clusters-On-connectVM-Cloud-connectVM-Magnum.html.md).

* Or, you may want to create a new cluster called *k8s-cluster*, just for this occasion – by using the following CLI command:

```
connectVM coe cluster create \
--cluster-template k8s-stable-1.23.5 \
--labels eodata_access_enabled=false,floating-ip-enabled=true,master-lb-enabled=true \
--merge-labels \
--keypair sshkey \
--master-count 3 \
--node-count 2 \
--master-flavor eo1.large \
--flavor eo1.large \
k8s-cluster

```

Warning

It takes some 10-20 minutes for the new cluster to form.

In the rest of this text we shall use cluster name *k8s-cluster* – be sure to use the name of the existing cluster instead.

No. 4 **Connect connectVM client to the cloud**

Prepare **connectVM** and **magnum** clients by executing *Step 2 Connect connectVM and Magnum Clients to Horizon Cloud* from article [How To Install connectVM and Magnum Clients for Command Line Interface to connectVM Cloud Horizon](How-To-Install-connectVM-and-Magnum-Clients-for-Command-Line-Interface-to-connectVM-Cloud-Horizon.html.md).

The Plan[🔗](#the-plan "Permalink to this headline")
---------------------------------------------------

> * Follow up the steps listed in Prerequisite No. 2 and install **kubectl** on the platform of your choice.
> * Use the existing Kubernetes cluster on connectVM or install a new one using the methods outlined in Prerequisites Nos. 3.
> * Use Step 2 in Prerequisite No. 4 to enable connection of **connectVM** and **magnum** clients to the cloud.

You are then going to connect **kubectl** to the Cloud.

Step 1 Create directory to download the certificates[🔗](#step-1-create-directory-to-download-the-certificates "Permalink to this headline")
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Create a new directory called *k8sdir* into which the certificates will be downloaded:

```
mkdir k8sdir

```

Once the certificate file is downloaded, you will execute a command similar to this:

```
export KUBECONFIG=/home/dusko/k8sdir/config

```

This assumes

> * using an Ubuntu environment (*/home*),
> * that the user is *dusko*,
> * the directory you just created */k8sdir* and, finally, that
> * *config* is the file which contains data for authorizing to the Kubernetes cluster.

Note

In Linux, a file may or may not have an extension, while on Windows, it must have an extension.

Step 2A Download Certificates From the Server using the CLI commands[🔗](#step-2a-download-certificates-from-the-server-using-the-cli-commands "Permalink to this headline")
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You will use command

```
connectVM coe cluster config

```

to download the files that **kubectl** needs for authentication with the server. See its input parameters using the **–help** parameter:

```
connectVM coe cluster config --help
usage: connectVM coe cluster config [-h]
   [--dir <dir>] [--force] [--output-certs]
   [--use-certificate] [--use-keystone]
    <cluster>

Get Configuration for a Cluster

positional arguments:
  <cluster>    The name or UUID of cluster to update

optional arguments:
  -h, --help           show this help message and exit
  --dir <dir>  Directory to save the certificate and config files.
  --force              Overwrite files if existing.
  --output-certs       Output certificates in separate files.
  --use-certificate    Use certificate in config files.
  --use-keystone       Use Keystone token in config files.

```

Download the certificates into the *k8sdir* folder:

```
connectVM coe cluster config \
--dir k8sdir \
--force \
--output-certs \
k8s-cluster

```

Four files will be downloaded into the folder:

```
ls k8sdir
ca.pem               cert.pem        config          key.pem

```

Parameter *–output-certs* produces *.pem* files, which are X.509 certificates, originally created so that they can be sent via email. File *config* combines the *.pem* files and contains all the information needed for **kubectl** to access the cloud. Using *–force* overwrites the existing files (if any), so you are guaranteed to work with only the latest versions of the files from the server.

The result of this command is shown in the row below:

```
export KUBECONFIG=/home/dusko/k8sdir/config

```

Copy this command and paste it into the command line of terminal, then press the *Enter* key on the keyboard to execute it. System variable KUBECONFIG will be thus initialized and the **kubectl** command will have access to the *config* file at all times.

This is the entire procedure in terminal window:

![download_config_cli.png](../_images/download_config_cli.png)

Step 2B Download Certificates From the Server using Horizon commands[🔗](#step-2b-download-certificates-from-the-server-using-horizon-commands "Permalink to this headline")
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You can download the config file from Horizon directly to your computer. First list the clusters with command **Container Infra** -> **Clusters**, find the cluster and click on the rightmost drop-down menu in its column:

![download_config_horizon.png](../_images/download_config_horizon.png)

Click on option **Show Cluster Config** and the config file will be downloaded to the editor:

![cluster_config_editor.png](../_images/cluster_config_editor.png)

From the editor, save it on disk. The file name will combine the name of the cluster with the word *config* and if you have downloaded the same file several times, there may be a dash followed by a number, like this:

```
k8s-cluster-config-1.yaml

```

For uniformity, save it to the same folder *k8sdir* as the *config* file and set up the KUBECONFIG variable to that address:

```
export KUBECONFIG=/home/dusko/k8sdir/k8s-cluster_config-1.yaml

```

Depending on your environment, you may need to open a new terminal window to make the above command work.

Step 3 Verify That kubectl Has Access to the Cloud[🔗](#step-3-verify-that-kubectl-has-access-to-the-cloud "Permalink to this headline")
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See basic data about the cluster with the following command:

```
kubectl get nodes -o wide

```

The result is:

![get_nodes_large.png](../_images/get_nodes_large.png)

That verifies that **kubectl** has proper access to the cloud.

To see available commands **kubectl** has, use:

```
kubectl --help

```

The listing is too long to reproduce here, but here is how it starts:

![kubectl_help.png](../_images/kubectl_help.png)

**kubectl** also has a long list of options, which are parameters that can be applied to any command. See them with

```
kubectl options

```

What To Do Next[🔗](#what-to-do-next "Permalink to this headline")
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With **kubectl** operational, you can

> * deploy apps on the cluster,
> * access multiple clusters,
> * create load balancers,
> * access applications in the cluster using port forwarding,
> * use Service to access application in a cluster,
> * list container images in the cluster
> * use Services, Deployments and all other resources in a Kubernetes cluster.

Kubernetes dashboard is a visual alternative to **kubectl**. To install it, see [Using Dashboard To Access Kubernetes Cluster Post Deployment On connectVM Cloud connectVM Magnum](Using-Dashboard-To-Access-Kubernetes-Cluster-Post-Deployment-On-connectVM-Cloud-connectVM-Magnum.html.md).