Configuring Core Dump

Scenario

Before creating or updating a pod, you can use the system.cci.io/coredump annotation to set the core_pattern of the kernel, so that you can use generated core dump files to locate the cause of the pod failure.

How to Use

When creating a pod, the core dump configuration (system.cci.io/coredump : '{"core_pattern": "/var/cores/core.%h.%e.%p.%t," max_size": 2048}') can be added to the annotations field. If the maximum size is not specified, the default value is 1024. Core dump will be used in the pod.

Constraints

The value of the system.cci.io/core_pattern field in the request must start with /var/, and the file path cannot contain vertical bars (|).
The configured path must exist in the container. You are advised to mount volumes to store core dump files persistently.

Creating a Pod Using ccictl

You can add an annotation to the workload to control whether to enable core dump for a pod.

apiVersion: cci/v2
kind: Deployment
metadata:
  annotations:
    description: ''
  labels: {}
  name: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      annotations:
        vm.cci.io/pod-size-specs: 2.00_4.0
        resource.cci.io/pod-size-specs: 2.00_4.0
        metrics.alpha.kubernetes.io/custom-endpoints: '[{api:'''',path:'''',port:'''',names:''''}]'
        system.cci.io/coredump: "{\"core_pattern\": \"/var/cores/core.%h.%e.%p.%t\",\"max_size\": 1024}"    # Enable core dump.
        log.stdoutcollection.kubernetes.io: '{"collectionContainers": ["container-0"]}'
      labels:
        app: nginx
    spec:
      containers:
        - image: library/nginx:stable-alpine-perl
          name: container-0
          resources:
            limits:
              cpu: 2000m
              memory: 4096Mi
            requests:
              cpu: 2000m
              memory: 4096Mi
          command: []
          lifecycle: {}
      dnsPolicy: ''
      imagePullSecrets:
        - name: imagepull-secret
      dnsConfig: {}
  minReadySeconds: 0
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 0
      maxUnavailable: 1