# Kubernetes Monitoring

This manual is for Kubernetes with minikub on a virtual machine running the Linux Ubuntu operating system.

## Quickstart

**Step 1 - Preparation**

Minikube must be running with Kubernetes version <=v1.23.0 and the Kubernetes API must be exposed.

The recommended way to expose the API is to redirect the API port (default is `8443`). This can be done with the following command:

```bash
minikube start --kubernetes-version=v1.23.0 --ports=8443:8443
```

**Step 2 - Installation**

In Kubernetes, you must install kube-state-metrics and cAdvisor (cAdvisor is integrated into kubelet by default).

**Step 3 - kube-state-metrics**

For the purposes of the instructions, we used the example provided [here](https://github.com/RevDeBug/kube-state-metrics.git).

After downloading the entire folder to the virtual machine with Kubernetes, we type the following command:

```bash
kubectl apply -f path_to_folder
```

**Step 4 - Data collector**

The next step is to add a data collector to collect data from Kubernetes and send it to the OAP.

Download:

* [permissions file](https://github.com/RevDeBug/feature-kubernetes-monitor/blob/main/permissions.yaml)
* [open-telemetry file](https://github.com/RevDeBug/feature-kubernetes-monitor/blob/main/open-telemetry.yaml)

Then set the RevDeBug server address in the open-telemetry file - `REVDEBUG_SERVER_NAME`.

Then in the same file name your cluster k8s (in two places) - `YOUR_CLUSTER_NAME`.

**Step 5 - Running**

Run the deployment of these files after by:

```bash
kubectl apply -f path_to_folder_where_they_are_both_files
```

**Step 6 - Setup**

You need to copy the contents of the `.kube/config` file for Linux the full path is `/home/your_user/.kube/config`

{% code title="config" %}

```yaml
apiVersion: v1
clusters:
- cluster:
    certificate-authority: /home/ubuntu/.minikube/ca.crt
    extensions:
    - extension:
        last-update: Thu, 16 Mar 2023 12:22:22 UTC
        provider: minikube.sigs.k8s.io
        version: v1.29.0
      name: cluster_info
    server: https://my_k8s_adress:8443
  name: minikube
contexts:
- context:
    cluster: minikube
    extensions:
    - extension:
        last-update: Thu, 16 Mar 2023 12:22:22 UTC
        provider: minikube.sigs.k8s.io
        version: v1.29.0
      name: context_info
    namespace: default
    user: minikube
  name: minikube
current-context: minikube
kind: Config
preferences: {}
users:
- name: minikube
  user:
    client-certificate: /home/ubuntu/.minikube/profiles/minikube/client.crt
    client-key: /home/ubuntu/.minikube/profiles/minikube/client.key
```

{% endcode %}

Then copy the 3 certificates whose paths are given in the config file:&#x20;

* `/home/ubuntu/.minikube/ca.crt`
* `/home/ubuntu/.minikube/profiles/minikube/client.crt`
* `/home/ubuntu/.minikube/profiles/minikube/client.key`

In the next step, switch to the server with RevDeBug:

* Go to the `/var/revdebug/apm-oap/config/k8s` folder - if the folder does not exist then create it.
* Create a new file starting with config, e.g. `config-cluster1`, `config-name`.
* Next, create a folder where we will keep the previously downloaded keys, for example: `name_your_folder_with_certs`.
* In the `config-your_name` file, we paste the contents of our config from minikub.
* We are adjusting the verifier paths to the RevDeBug container:&#x20;

```
certificate-authority: /revdebug/config/k8s/name_of_folder_with_cert/ca.crt
client-certificate: /revdebug/config/k8s/name_of_folder_with_cert/client.crt
client-key: /revdebug/config/k8s/name_of_folder_with_cert/client.key
```

* We adjust the Kubernetes address - by default, there is an internal API set the address of your Kubernetes/Port API that we exposed at the beginning. Important: always **https**.

```yaml
apiVersion: v1
clusters:
- cluster:
    certificate-authority: /revdebug/config/k8s/name_of_folder_with_cert/ca.crt
    extensions:
    - extension:
        last-update: Thu, 16 Mar 2023 12:22:22 UTC
        provider: minikube.sigs.k8s.io
        version: v1.29.0
      name: cluster_info
    server: https://my_k8s_adress:8443
  name: minikube
contexts:
- context:
    cluster: minikube
    extensions:
    - extension:
        last-update: Thu, 16 Mar 2023 12:22:22 UTC
        provider: minikube.sigs.k8s.io
        version: v1.29.0
      name: context_info
    namespace: default
    user: minikube
  name: minikube
current-context: minikube
kind: Config
preferences: {}
users:
- name: minikube
  user:
    client-certificate:  /revdebug/config/k8s/name_of_folder_with_cert/client.crt
    client-key: /revdebug/config/k8s/name_of_folder_with_cert/client.ke

```

**Step 7 - Environment variables**

Go to the folder with docker-compose on the RevDeBug server. Add the following variables to the `.env` file:

* `SW_OTEL_RECEIVER_ENABLED_HANDLERS="oc"`
* `SW_OTEL_RECEIVER=default`
* `SW_OTEL_RECEIVER_ENABLED_OC_RULES=k8s-cluster,k8s-node,k8s-service`

{% hint style="info" %}
If you have virtual machine monitoring set up then do not remove `SW_OTEL_RECEIVER_ENABLED_OC_RULES:vm,oap` just add more rules after the comma.
{% endhint %}

**Step 8 - Down/up RevDeBug compose**

```bash
docker compose -p revdebug up -d
```

If you want to enable Kubernetes monitoring option, please contact <sales@revdebug.com>