Static Pods
Static Pods
Static pods are run directly by the kubelet bypassing the Kubernetes API server checks and validations.
Most of the time DaemonSet is a better alternative to static pods, but some workloads need to run
before the Kubernetes API server is available or might need to bypass security restrictions imposed by the API server.
See Kubernetes documentation for more information on static pods.
Configuration
Static pod definitions are specified in the Talos machine configuration:
machine:
pods:
- apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx
Talos renders static pod definitions to the kubelet manifest directory (/etc/kubernetes/manifests), kubelet picks up the definition and launches the pod.
Talos accepts changes to the static pod configuration without a reboot.
Usage
Kubelet mirrors pod definition to the API server state, so static pods can be inspected with kubectl get pods, logs can be retrieved with kubectl logs, etc.
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-talos-default-master-2 1/1 Running 0 17s
If the API server is not available, status of the static pod can also be inspected with talosctl containers --kubernetes:
$ talosctl containers --kubernetes
NODE NAMESPACE ID IMAGE PID STATUS
172.20.0.3 k8s.io default/nginx-talos-default-master-2 k8s.gcr.io/pause:3.6 4886 SANDBOX_READY
172.20.0.3 k8s.io └─ default/nginx-talos-default-master-2:nginx docker.io/library/nginx:latest
...
Logs of static pods can be retrieved with talosctl logs --kubernetes:
$ talosctl logs --kubernetes default/nginx-talos-default-master-2:nginx
172.20.0.3: 2022-02-10T15:26:01.289208227Z stderr F 2022/02/10 15:26:01 [notice] 1#1: using the "epoll" event method
172.20.0.3: 2022-02-10T15:26:01.2892466Z stderr F 2022/02/10 15:26:01 [notice] 1#1: nginx/1.21.6
172.20.0.3: 2022-02-10T15:26:01.28925723Z stderr F 2022/02/10 15:26:01 [notice] 1#1: built by gcc 10.2.1 20210110 (Debian 10.2.1-6)
Troubleshooting
Talos doesn’t perform any validation on the static pod definitions.
If the pod isn’t running, use kubelet logs (talosctl logs kubelet) to find the problem:
$ talosctl logs kubelet
172.20.0.2: {"ts":1644505520281.427,"caller":"config/file.go:187","msg":"Could not process manifest file","path":"/etc/kubernetes/manifests/talos-default-nginx-gvisor.yaml","err":"invalid pod: [spec.containers: Required value]"}
Resource Definitions
Static pod definitions are available as StaticPod resources combined with Talos-generated control plane static pods:
$ talosctl get staticpods
NODE NAMESPACE TYPE ID VERSION
172.20.0.3 k8s StaticPod default-nginx 1
172.20.0.3 k8s StaticPod kube-apiserver 1
172.20.0.3 k8s StaticPod kube-controller-manager 1
172.20.0.3 k8s StaticPod kube-scheduler 1
Talos assigns ID <namespace>-<name> to the static pods specified in the machine configuration.
On control plane nodes status of the running static pods is available in the StaticPodStatus resource:
$ talosctl get staticpodstatus
NODE NAMESPACE TYPE ID VERSION READY
172.20.0.3 k8s StaticPodStatus default/nginx-talos-default-master-2 2 True
172.20.0.3 k8s StaticPodStatus kube-system/kube-apiserver-talos-default-master-2 2 True
172.20.0.3 k8s StaticPodStatus kube-system/kube-controller-manager-talos-default-master-2 3 True
172.20.0.3 k8s StaticPodStatus kube-system/kube-scheduler-talos-default-master-2 3 True