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Obmondo K8s Agent

This agent runs inside the Kubernetes cluster and pulls the metrics about the cluster from the Prometheus API. These metrics are then forwarded to our Obmondo API.

Adding K8s Agent to your cluster​

The agent depends upon :

  • a TLS secret certificate obmondo-clientcert which can be found in most of our customer clusters under monitoring namespace.
  • a docker config secret for pulling the docker image from our gitlab repo

To create the TLS secret :

# connect to the k8s cluster you want to deploy agent on
# get the tls.crt and tls.key from the existing secret into a local file

$ kubectl get secret obmondo-clientcert -n monitoring --template="{{index .data \"tls.crt\" | base64decode}}" > tls.crt
$ kubectl get secret obmondo-clientcert -n monitoring --template="{{index .data \"tls.key\" | base64decode}}" > tls.key

# verify the issuer using openssl
$ openssl x509 -in tls.crt -noout -text

# create the new secret and seal it using kubeseal
$ kubectl create secret tls k8s-agent-tls -n obmondo --dry-run=client --key="tls.key" --cert="tls.crt" -o yaml | kubeseal --controller-namespace system --controller-name sealed-secrets > k8s-agent-tls.yaml

To create the docker secret :

# create a access token in obmondo-k8s-agent gitlab repo
# with read_registry permission, or ask Ashish to provide the token

# connect to the K8s cluster you want to deploy agent on
$ kubectl create secret --namespace obmondo --dry-run=client docker-registry <secret-name> --docker-server=registry.obmondo.com --docker-username="oauth" --docker-password="<access-token>" -o yaml | kubeseal --controller-namespace system --controller-name sealed-secrets -o yaml > my-registry-access-token.yaml

Create an application file for ArgoCD

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: obmondo-k8s-agent
  namespace: argocd
  finalizers:
  - resources-finalizer.argocd.argoproj.io
spec:
  destination:
    server: https://kubernetes.default.svc
    namespace: obmondo
  project: default
  source:
    path: argocd-helm-charts/obmondo-k8s-agent
    repoURL: https://gitlab.enableit.dk/kubernetes/kubeaid.git
    targetRevision: HEAD
    helm:
      valueFiles:
      - values.yaml
      - /path/to/override/values.yaml
  syncPolicy:
    syncOptions:
    - CreateNamespace=true

Override the default access token of Helm chart by specifying it in the values file for ArgoCD

imagePullSecrets:
  - name: 'my-registry-access-token'