kube-slack

kube-slack is a monitoring service for Kubernetes. When a pod has failed, it will publish a message in Slack channel.

Installation

A Helm chart is available

1. Create an incoming webhook:
   1. In the Slack interface, click on the gears button (Channel Settings) near the search box.
   2. Select "Add an app or integration"
   3. Search for "Incoming WebHooks"
   4. Click on "Add configuration"
   5. Select the channel you want the bot to post to and submit.
   6. You can customize the icon and name if you want.
   7. Take note of the "Webhook URL". This will be something like https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX
2. (optional) If your kubernetes uses RBAC, you should apply the following manifest as well:

---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: kube-slack
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get", "watch", "list"]
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: kube-slack
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: kube-slack
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: kube-slack
subjects:
  - kind: ServiceAccount
    name: kube-slack
    namespace: kube-system

Load this Deployment into your Kubernetes. Make sure you set SLACK_URL to the Webhook URL and uncomment serviceAccountName if you use RBAC

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: kube-slack
  namespace: kube-system
spec:
  replicas: 1
  revisionHistoryLimit: 3
  template:
    metadata:
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ""
      name: kube-slack
      labels:
        app: kube-slack
    spec:
     # Uncomment serviceAccountName if you use RBAC.
     # serviceAccountName: kube-slack
      containers:
      - name: kube-slack
        image: willwill/kube-slack:v4.2.0
        env:
        - name: SLACK_URL
          value: https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX
        resources:
          requests:
            memory: 30M
            cpu: 5m
      tolerations:
      - effect: NoSchedule
        key: node-role.kubernetes.io/master
      - key: CriticalAddonsOnly
        operator: Exists

3. To test, try creating a failing pod. The bot should announce in the channel after 15s with the status ErrImagePull. Example of failing image:

apiVersion: v1
kind: Pod
metadata:
  name: kube-slack-test
spec:
  containers:
  - image: willwill/inexisting
    name: kube-slack-test

Additionally, the following environment variables can be used:

• TICK_RATE: How often to update in milliseconds. (Default to 15000 or 15s)
• FLOOD_EXPIRE: Repeat notification after this many milliseconds has passed after status returned to normal. (Default to 60000 or 60s)
• NOT_READY_MIN_TIME: Time to wait after pod become not ready before notifying. (Default to 60000 or 60s)
• METRICS_CPU: Enable/disable metric alerting on cpu (Default true)
• METRICS_MEMORY: Enable/disable metric alerting on memory (Default true)
• METRICS_PERCENT: Set percentage threshold on metric alerts (Default 80)
• METRICS_REQUESTS: If no metrics limit defined, alert if the pod utilization is more than the resource request amount (this may be very noisy, Default false).
• KUBE_USE_KUBECONFIG: Read Kubernetes credentials from active context in ~/.kube/config (default off)
• KUBE_USE_CLUSTER: Read Kubernetes credentials from pod (default on)
• KUBE_NAMESPACES_ONLY: Monitor a list of specific namespaces, specified either as json array or as a string of comma seperated values (foo_namespace,bar_namespace).
• SLACK_CHANNEL: Override channel to send
• SLACK_USERNAME: Override username to send
• SLACK_PROXY: URL of HTTP proxy used to connect to Slack
• RECOVERY_ALERT: Set to false to disable alert on pod recovery

Annotations

Pods can be marked with the following annotations:

• kube-slack/ignore-pod: Ignore all errors from this pod
• kube-slack/slack-channel: Name of slack channel to notify (eg. #monitoring)

License

MIT License