Send Slack Notification when Pod is in crashloopbackoff state
Gianluca
Posted on November 7, 2023
Projectsveltos is a Kubernetes add-on controller that simplifies the deployment and management of add-ons and applications across multiple clusters. It runs in the management cluster and can programmatically deploy and manage add-ons and applications on any cluster in the fleet, including the management cluster itself. Sveltos supports a variety of add-on formats, including Helm charts, raw YAML, Kustomize, Carvel ytt, and Jsonnet.
Projectsveltos though goes beyond managing add-ons and applications across a fleet of #Kubernetes Clusters. It can also proactively monitor cluster health and provide real-time notifications.
For example, Sveltos can be configured to detect pods in a crashloopbackoff state within any of the managed clusters and send immediate #slack notifications alerting administrators to potential issues.
Detect a Pod in crashloopbackoff state
Projectsveltos has two custom resource definitions to achieve this goal:
- HealthCheck defines what to monitor. It accepts a #lua script. Sveltos's monitoring capabilities extend to all Kubernetes resources, including custom resources, ensuring comprehensive oversight of your infrastructure.
- ClusterHealthCheck defines which clusters to monitor and where to send notifications
apiVersion: lib.projectsveltos.io/v1alpha1
kind: HealthCheck
metadata:
name: crashing-pod
spec:
group: ""
version: v1
kind: Pod
script: |
function evaluate()
hs = {}
hs.status = "Healthy"
hs.ignore = true
if obj.status.containerStatuses then
local containerStatuses = obj.status.containerStatuses
for _, containerStatus in ipairs(containerStatuses) do
if containerStatus.state.waiting and containerStatus.state.waiting.reason == "CrashLoopBackOff" then
hs.status = "Degraded"
hs.ignore = false
hs.message = obj.metadata.namespace .. "/" .. obj.metadata.name .. ":" .. containerStatus.state.waiting.message
if containerStatus.lastState.terminated and containerStatus.lastState.terminated.reason then
hs.message = hs.message .. "\nreason:" .. containerStatus.lastState.terminated.reason
end
end
apiVersion: lib.projectsveltos.io/v1alpha1
kind: ClusterHealthCheck
metadata:
name: crashing-pod
spec:
clusterSelector: env=fv
livenessChecks:
- name: crashing-pod
type: HealthCheck
livenessSourceRef:
kind: HealthCheck
apiVersion: lib.projectsveltos.io/v1alpha1
name: crashing-pod
notifications:
- name: slack
type: Slack
notificationRef:
apiVersion: v1
kind: Secret
name: slack
namespace: default
All YAMLs used in this example can be found here
Centralised View
Projectsveltos also offers the ability to display health of the clusters it manages. This information can then be accessed and displayed using Sveltos' CLI in the management cluster.
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The GitHub repo is a great resource for getting started with the project. It contains the code, documentation, and examples. You can also find the latest news and updates on the project on the GitHub repo.
Thank you for reading!
Posted on November 7, 2023
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