Stage 1. Pod not scheduled
During the launch, Pods go through a sequence of execution stages. The first stage is to assign a Node on which the Pod should launch. This validator detects a condition when a Pod is not yet scheduled to run on a Node. There are numerous reasons why Pods can be stuck in the scheduling stage. The reasons can be combinations of insufficient cluster resources, suboptimal node selectors, node affinity, pod affinity and anti-affinity, PodOverhead, node taints, and tolerations. There is also a NodeRestriction admission controller available as a plugin which can restrict scheduling of certain workloads on certain nodes. Refer to the links below for details on troubleshooting Pod scheduling failures.
Affected Resources: Pod
Example
kind: Pod
...
status:
conditions:
- type: PodScheduled
status: "False"
lastProbeTime: null
lastTransitionTime: 2022-01-01T00:00:00Z
Resolution
Resolution Examples
# Node Selector
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx
nodeSelector:
disktype: ssd
# Node Affinity
apiVersion: v1
kind: Pod
metadata:
name: with-node-affinity
spec:
affinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
nodeSelectorTerms:
- matchExpressions:
- key: kubernetes.io/e2e-az-name
operator: In
values:
- e2e-az1
- e2e-az2
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 1
preference:
matchExpressions:
- key: another-node-label-key
operator: In
values:
- another-node-label-value
containers:
- name: with-node-affinity
image: k8s.gcr.io/pause:2.0
# Pod Affinity and Anti-Affinity
apiVersion: v1
kind: Pod
metadata:
name: with-pod-affinity
spec:
affinity:
podAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: security
operator: In
values:
- S1
topologyKey: topology.kubernetes.io/zone
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
podAffinityTerm:
labelSelector:
matchExpressions:
- key: security
operator: In
values:
- S2
topologyKey: topology.kubernetes.io/zone
containers:
- name: with-pod-affinity
image: k8s.gcr.io/pause:2.0
# PodOverhead
---
kind: RuntimeClass
apiVersion: node.k8s.io/v1
metadata:
name: kata-fc
handler: kata-fc
overhead:
podFixed:
memory: "120Mi"
cpu: "250m"
---
apiVersion: v1
kind: Pod
metadata:
name: test-pod
spec:
runtimeClassName: kata-fc
containers:
- name: busybox-ctr
image: busybox
stdin: true
tty: true
resources:
limits:
cpu: 500m
memory: 100Mi
- name: nginx-ctr
image: nginx
resources:
limits:
cpu: 1500m
memory: 100Mi
# Taints and Tolerations
apiVersion: v1
kind: Pod
metadata:
name: nginx
labels:
env: test
spec:
containers:
- name: nginx
image: nginx
imagePullPolicy: IfNotPresent
tolerations:
- key: "example-key"
operator: "Exists"
effect: "NoSchedule"
Learn More
Need other validation rules?
Please let us know if there are other built-in validation rules you would like to see in Kubevious to detect misconfigurations and violations to best practices. Optionally, you can provide your details so we can reach out to you with follow-up questions.