Application Checklist for Kubernetes
By
bltd2a1894de5aec444
June 25,
2019
Find out what the best practices are for running applications in Kubernetes with this convenient application checklist.
Last week we did a run down of what you need for a production ready cluster. In this part 2 we’ll outline a checklist of best practices for applications running in Kubernetes.
If any of these topics interest you, and you are in London, we’re also running a workshop called “Production Ready Kubernetes”. Sign up here.
Application Checklist for Kubernetes
These are the areas that need attention before running your cluster in production.
| What is it | Why you need it | Options | |
|---|---|---|---|
| Readiness Check | Endpoints for Kubernetes to monitor your application lifecycle. | Allows Kubernetes to restart or stop traffic to a pod. Readiness failure is transient and tells Kubernetes to route traffic elsewhere Readiness failure is useful for startup and load management | Read: Resilient apps with Liveness and Readiness probes. |
| Liveness check | Endpoints for Kubernetes to monitor your application lifecycle. | Liveness failure is for telling Kubernetes to restart the pod. | Read: Resilient apps with Liveness and Readiness probes. |
| Metric instrumentation | Code and libraries used in your code to expose metrics. | Allows measuring operation of application and enables many more advanced use cases. | Prometheus, New Relic, Datadog and others. Read: Monitoring Kubernetes with Prometheus. |
| Dashboards | View of metrics. | You need to make sense out of the data. | Grafana Weave Cloud |
| Playbooks/Runbooks | Rich guides for your engineers on how-to operate the system and fault find when things go wrong. | Nobody is at their sharpest at 03:00 AM. Knowledge deteriorates over time | Confluence Markdown files Weave Cloud Notebooks |
| Limits and requests | Explicit resource allocation for pods. | Allows Kubernetes to make good scheduling decisions. | Read: Kubernetes Pod Resource Limitations and Quality of Service. |
| Labels and annotations | Metadata held by Kubernetes. | Makes workload management easier and allows other tools to work with standard Kubernetes definitions. | Read: Labels and Selectors in Kubernetes. |
| Alerts | Automated notifications on defined trigger. | You need to know when your service degrades. | Prometheus & Alertmanager. Read: Labels in Prometheus alerts: think twice before using them. |
| Structured logging output | Output logs in a machine readable format to facilitate searching & indexing. | Trace what went wrong when something does. | ELK stack (Elasticsearch, Logstash and Kibana). Many commercial offerings. |
| Tracing instrumentation | Instrumentation to send request processing details to a collection service. | Sometimes the only way of figuring out where latency is coming from | Zipkin, Lightstep, Appdash, Tracer, Jaeger |
| Graceful shutdowns | Applications respond to SIGTERM correctly. | This is how Kubernetes will tell your application to end. | Read: 10 tips for Building and Managing Containers |
| Graceful dependency (w. Readiness check) | Applications don’t assume dependencies are available. Wait for other services before reporting ready. | Avoid headaches that come with a service order requirement. | Read: 10 tips for Building and Managing Containers |
| Configmaps | Define a configuration file for your application in Kubernetes using configmaps. | Easy to reconfigure an app without rebuilding, allows config to be versioned. | Read: Best Practices for Designing and Building Containers for Kubernetes |
| Label the docker images with the code commit SHA. | Makes tracing image to code trivial. | Locked down runtime context | Read: Introduction to Kubernetes Security |
| Locked down runtime context | Use deliberately secure configuration for application runtime context. | Reduces attack surface, makes privileges explicit. | Read: Continuous Security for GitOps |
