added k8s guide for managed VM

docs/managed_victoriametrics/how-to-monitor-k8s.md

@@ -0,0 +1,121 @@
+# Kubernetes Monitoring with Managed VictoriaMetrics
+
+Monitoring kubernetes cluster is necessary to build SLO/SLI, to analyze performance and cost-efficiency of your workloads. 
+
+To enable enable kubernetes cluster monitoring, we will be collecting metrics about cluster performance and utilization from kubernetes components like `kube-api-server`, `kube-controller-manager`, `kube-scheduler`, `kube-state-metrics`,  `etcd`, `core-dns`, `kubelet` and `kube-proxy`. We will also install some recording rules, alert rules and dashboards to provide visibility of cluster performance, as well as alerting for cluster metrics.
+For node resource utilization we will be collecting metrics from `node-exporter`. We will also install dashboard and alerts for node related metrics
+
+For workloads monitoring in kubernetes cluster we will have [VictoriaMetrics Operator](https://docs.victoriametrics.com/operator/VictoriaMetrics-Operator.html). It enables us to define scrape jobs using kubernetes CRDs [VMServiceScrape](https://docs.victoriametrics.com/operator/design.html#vmservicescrape), [VMPodScrape](https://docs.victoriametrics.com/operator/design.html#vmpodscrape). To add alerts or recording rules for workloads we can use [VMRule](https://docs.victoriametrics.com/operator/design.html#vmrule) CRD
+
+## Installation
+
+In this guide we will be using [victoria-metrics-k8s-stack](https://github.com/VictoriaMetrics/helm-charts/tree/master/charts/victoria-metrics-k8s-stack) helm chart
+
+This chart will install `VMOperator`, `VMAgent`, `NodeExporter`, `kube-state-metrics`, `grafana` and some service scrape configurations to start monitoring kuberentes cluster components
+
+### Prerequisites
+- Active Managed VictoriaMetrics instance. You can learn how to signup for Managed VictoriaMetrics [here](https://docs.victoriametrics.com/managed-victoriametrics/quickstart.html#how-to-register). 
+- Access to your kubernetes cluster
+- Helm binary. You can find installation [here]https://helm.sh/docs/intro/install/()
+
+### Installation steps
+Install the Helm chart in a custom namespace
+
+
+1. Create a unique Kubernetes namespace, for example monitoring
+```
+kubectl create namespace monitoring
+```
+2. Create kubernetes-secrets with token to access your dbaas deployment
+```
+kubectl --namespace monitoring create secret generic dbaas-write-access-token --from-literal=bearerToken=your-token
+
+kubectl --namespace monitoring create secret generic dbaas-read-access-token --from-literal=bearerToken=your-token
+```
+
+> You can find your access token on the "Access" tab of your deployment
+> ![access tijen](./k8s-monitoring-access-token.png)
+
+
+3. Set up a Helm repository using the following commands:
+```
+helm repo add grafana https://grafana.github.io/helm-charts
+helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
+helm repo add vm https://victoriametrics.github.io/helm-charts
+helm repo update
+```
+
+4. Create a YAML file of Helm values called dbaas.yaml with following content
+```yaml
+externalVM:
+  read:
+    url: 
+    bearerTokenSecret:
+      name: dbaas-write-access-token
+      key: bearerToken
+  write:
+    url: 
+    bearerTokenSecret:
+      name: dbaas-read-access-token
+      key: bearerToken
+
+vmsingle:
+  enabled: false
+
+vmcluster:
+  enabled: false
+
+vmalert:
+  enabled: true
+  spec:
+    evaluationInterval: 15s
+
+vmagent:
+  enabled: true
+
+  spec:
+    scrapeInterval: 30s
+    externalLabels:
+      cluster: cluster-name
+
+# dependencies  
+# Grafana dependency chart configuration. For possible values refer to https://github.com/grafana/helm-charts/tree/main/charts/grafana#configuration
+grafana:
+  enabled: true
+```
+
+5. Install VictoriaMetrics-k8s-stack helm chart
+
+```
+helm --namespace monitoring install vm vm/victoria-metrics-k8s-stack -f dbaas.yaml -n monitoring
+```
+
+### Connect to grafana and create your datasource
+
+> If you are using external grafana, you can skip steps 1-3 and you will need to import dashboards that can be found here manually
+
+
+1. Get grafana password
+```
+kubectl --namespace monitoring get secret vm-grafana  -o jsonpath="{.data.admin-password}" | base64 -d
+```
+2. Connect to grafana
+```
+kubectl --namespace monitoring port-forward service/vm-grafana 3000:80
+```
+3. Open grafana in your browser http://localhost:3000/datasources
+   
+   Use admin as username and password from previous step
+
+4. Click on add datasource
+   
+   Choose VictoriaMetrics or Prometheus as datasource type. Make sure you made this datasource as default for dashboards to work.
+
+![datasource](./k8s-monitoring-datasource.png)
+
+> You can find token and URL in your deployment, on access tab
+
+### Test it
+
+You should be able to see data that was sent to your dbaas using VMAgent dashboard http://localhost:3000/d/G7Z9GzMGz/victoriametrics-vmagent/
+You also will be able to see bunch of kuberentes dashboards in your grafana