K8s init container restart itself - kubernetes

Question

I have pod that includes one init container and one app container,
between them there is a volume with shared folder.
My issue is that once a day or even more, the init container run itself and therefore it delete the node modules from the volume, then the main app crash because of missing modules.
The app container is not making any restarts, only the init container.
is anyone familiar with this issue in k8s? why those restarts happens only in the init container?
Thanks :)
edit:
the deployment yaml file -
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
annotations:
deployment.kubernetes.io/revision: "25"
creationTimestamp: "2020-05-19T06:48:18Z"
generation: 25
labels:
apps: ******
commit: ******
name: *******
namespace: fleet
resourceVersion: "24059934"
selfLink: *******
uid: *******
spec:
progressDeadlineSeconds: 600
replicas: 1
revisionHistoryLimit: 10
selector:
matchLabels:
app: *******
strategy:
rollingUpdate:
maxSurge: 1
maxUnavailable: 25%
type: RollingUpdate
template:
metadata:
creationTimestamp: null
labels:
app: *******
commit: *******
revision: *******
spec:
containers:
image: XXXXXXXXXXXX
imagePullPolicy: IfNotPresent
livenessProbe:
failureThreshold: 3
httpGet:
path: /ping
port: http
scheme: HTTP
initialDelaySeconds: 120
periodSeconds: 30
successThreshold: 1
timeoutSeconds: 30
name: *******
ports:
- containerPort: 1880
name: http
protocol: TCP
readinessProbe:
failureThreshold: 20
httpGet:
path: /ping
port: http
scheme: HTTP
initialDelaySeconds: 20
periodSeconds: 5
successThreshold: 1
timeoutSeconds: 30
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /opt/breeze
name: workdir
dnsPolicy: ClusterFirst
imagePullSecrets:
- name: flowregistrykey
initContainers:
image: XXXXXXXXXXXX
imagePullPolicy: IfNotPresent
name: get-flow-json
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /work-dir
name: workdir
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
terminationGracePeriodSeconds: 30
volumes:
- emptyDir: {}
name: workdir
status:
availableReplicas: 1
conditions:
- lastTransitionTime: "2020-06-01T12:30:10Z"
lastUpdateTime: "2020-06-01T12:30:10Z"
message: Deployment has minimum availability.
reason: MinimumReplicasAvailable
status: "True"
type: Available
- lastTransitionTime: "2020-05-19T06:48:18Z"
lastUpdateTime: "2020-06-01T12:45:05Z"
message: ReplicaSet "collection-associator.sandbox.services.collection-8784dcb9d"
has successfully progressed.
reason: NewReplicaSetAvailable
status: "True"
type: Progressing
observedGeneration: 25
readyReplicas: 1
replicas: 1
updatedReplicas: 1
and this image explain the problem-
the pod was created 7 days ago, but the files inside were created today, and there is no node_modules folder - because only the init container run again and not the app container so there was no mpm install

Answer 1

the init container run itself and therefore it delete the node modules from the volume
initContainer is only run when a pod restart. Don't treat it as service or application. It should be a script, a job only for setup before your application.
then the main app crash because of missing modules.
node_modules is not dynamic loading. It's loaded when you npm start
You might want to try livenessProbe.
Many applications running for long periods of time eventually transition to broken states, and cannot recover except by being restarted. Kubernetes provides liveness probes to detect and remedy such situations.
initContainers:
- name: set-delete-time
command: ["/bin/sh","-c"]
args:
- |
# Let's set 3600
echo 3600 > deleteTime
...
containers:
- name: node-app
livenessProbe:
exec:
command:
# If deleteTime > 0 exit 0
# Else /tmp/deleteTime - $periodSeconds > /tmp/deleteTime
- cat
- /tmp/deleteTime
- ...
initialDelaySeconds: 5
periodSeconds: 5