k8s-restart-helper.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: restart-helper
---
# Allows the service account to:
#
# - Get namespaces.
# - Get/patch our deployments and statefulsets, to allow the
#   "restart rollout" command to work.
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: restart-helper
rules:
  - apiGroups: [ "" ]
    resources: [ "namespaces" ]
    verbs: [ "get" ]
  - apiGroups: [ "apps", "extensions" ]
    resources: [ "deployments", "statefulsets" ]
    verbs: [ "get", "patch" ]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: restart-helper
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: restart-helper
subjects:
  - kind: ServiceAccount
    name: restart-helper
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: restart-helper
  labels:
    app: restart-helper
spec:
  replicas: 1
  template:
    metadata:
      annotations:
        # Increase to force a restart
        bump: bump-1
      name: restart-helper
      labels:
        app: restart-helper
    spec:
      # Binds to the previously created service account
      serviceAccountName: restart-helper
      containers:
        - name: restart-helper
          image: alpine:3.14.0
          imagePullPolicy: IfNotPresent
          # The port needs to be the same as the one defined in
          # qvalet configuration
          ports:
            - containerPort: 7055
              name: http
          readinessProbe:
            httpGet:
              port: 7055
              path: /healthz
              scheme: HTTP
          command:
            - sh
            - -c
            - |
              set -ex

              QVALET_VERSION="v2.0.0"

              QVALET="/qvalet"
              KUBECTL="/kubectl"

              # Download the required tools
              wget -O "$QVALET" "https://github.com/cmaster11/qvalet/releases/download/$QVALET_VERSION/qvalet-linux-amd64"
              wget -O "$KUBECTL" "https://dl.k8s.io/release/$(wget -O- https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

              chmod +x "$QVALET"
              chmod +x "$KUBECTL"

              # Defines the configuration for qvalet
              cat << EOF > /config.yaml
              listeners:

                "/restart/:type/:name":

                  log: all
                  return: output

                  # Command to run, and list of arguments
                  command: "$KUBECTL"
                  args:
                    - rollout
                    - restart
                    - "{{ .type }}/{{ .name }}"
              EOF

              # By using `exec`, we replace the current process with
              # qvalet one, which allows the program to receive all
              # system signals. Necessary for graceful shutdown
              exec $QVALET
      restartPolicy: Always
  selector:
    matchLabels:
      app: restart-helper
---
apiVersion: v1
kind: Service
metadata:
  name: restart-helper
spec:
  selector:
    app: restart-helper
  ports:
    - port: 7055
      name: http
---
# Uncomment to use the default ingress resource type
#apiVersion: networking.k8s.io/v1
#kind: Ingress
#metadata:
#  name: restart-helper
#spec:
#  rules:
#    - host: myhost.mydomain.com
#      http:
#        paths:
#          - path: /
#            pathType: Prefix
#            backend:
#              service:
#                name: restart-helper
#                port:
#                  number: 7055