# Copyright 2019 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


# Deploy this DaemonSet to enable kdump on the COS nodes with the
# "cloud.google.com/gke-kdump-enabled=true" label.
#
# WARNING: Enabling kdump requires node reboot. Therefore, in order to avoid
# disrupting your workloads, it is recommended to create a new node pool with
# the "cloud.google.com/gke-kdump-enabled=true" label in your cluster,
# deploy the DaemonSet to enable kdump in that node pool, and then migrate
# your workloads to the new node pool.

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: enable-kdump
  namespace: kube-system
spec:
  selector:
    matchLabels:
      name: enable-kdump
  updateStrategy:
    type: RollingUpdate
  template:
    metadata:
      labels:
        name: enable-kdump
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: cloud.google.com/gke-accelerator
                    operator: In
                    values:
                      - nvidia-h100-80gb
      tolerations:
        - operator: "Exists"
      volumes:
        - name: host
          hostPath:
            path: /
      initContainers:
        - name: enable-kdump
          image: ubuntu
          command:
            - /bin/bash
            - -c
            - |
              function verify_base_image {
                local id="$(grep "^ID=" /host/etc/os-release)"
                if [[ "${id#*=}" != "cos" ]]; then
                  echo "This kdump feature switch is designed to run on Container-Optimized OS only"
                  exit 0
                fi
              }
              function check_kdump_feature {
                chroot /host /usr/sbin/kdump_helper show
              }
              function enable_kdump_feature_and_reboot_if_needed {
                chroot /host /usr/sbin/kdump_helper enable
                local -r is_enabled=$(chroot /host /usr/sbin/kdump_helper show | grep "kdump enabled" | sed -rn "s/kdump enabled: (.*)/\1/p")
                local -r is_ready=$(chroot /host /usr/sbin/kdump_helper show | grep "kdump ready" | sed -rn "s/kdump ready: (.*)/\1/p")
                if [[ "${is_enabled}" == "true" && "${is_ready}" == "false" ]]; then
                  echo "kdump is enabled. Rebooting for it to take effect."
                  chroot /host systemctl reboot
                fi
              }
              verify_base_image
              check_kdump_feature
              enable_kdump_feature_and_reboot_if_needed
          resources:
            requests:
              memory: 5Mi
              cpu: 5m
          securityContext:
            privileged: true
          volumeMounts:
            - name: host
              mountPath: /host
      containers:
        - image: gke.gcr.io/pause:3.8@sha256:880e63f94b145e46f1b1082bb71b85e21f16b99b180b9996407d61240ceb9830
          name: pause
      nodeSelector:
        "gke-kdump-enabled": "true"
        "cloud.google.com/gke-os-distribution": "cos"
