Kubernetes Crashloopbackoff With Minikube

Question

So I am learning about Kubernetes with a guide, I am trying to deploy a MongoDB Pod with 1 replica. This is the deployment config file.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mongodb-deployment
  labels:
    app: mongodb
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mongodb
  template:
    metadata:
      labels:
        app: mongodb
    spec:
      containers:
        - name: mongodb
          image: mongo
          ports:
            - containerPort: 27017
          env:
            - name: MONGO_INITDB_ROOT_USERNAME
              valueFrom:
                secretKeyRef:
                  name: mongodb-secret
                  key: mongo-root-username
            - name: MONGO_INITDB_ROOT_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: mongodb-secret
                  key: mongo-root-password
---
apiVersion: v1
kind: Service
metadata:
  name: mongodb-service
spec:
  selector:
    app: mongodb
  ports:
    - protocol: TCP
      port: 27017
      targetPort: 27017

I also try to deploy a Mongo-Express Pod with almost the same config file, but I keep getting CrashLoopBackOff for both Pods, From the little understanding I have, this is caused by the container failing and restarting in a cycle. I tried going through the events with kubectl get events and I see that a warning with message Back-off restarting failed container keeps occurring. I also tried doing a little digging around and came across a solution that says to add

command: ['sleep']
args: ['infinity']

That fixed the CrashLoopBackOff issue, but when I try to get the logs for the Pod, nothing is displayed on the terminal. Please I need some help and possible explanation as how the command and args seem to fix it, also how do I stop this crash from happening to my Pods and current one, Thank you very much.

Answer 1

Try to figure out what and why it happened, run:

kubectl get pods

and after that

kubectl logs NAME_OF_POD_FROM_PREV_COMMAND

In my case the issue was "WARNING: MongoDB 5.0+ requires a CPU with AVX support, and your current system does not appear to have that!" So I just added image version:

containers:
  - name: mongodb
    image: mongo:4.0