Kubernetes manifest builder and explainer

Build holds a bundle — the objects you are writing together, shown as chips along the top. + Add… adds a kind (Deployment, StatefulSet, DaemonSet, Job, CronJob, Service of any type, Ingress, ConfigMap, Secret, PersistentVolumeClaim, HorizontalPodAutoscaler v2, NetworkPolicy, ServiceAccount); a new Service takes its selector and ports from the workload in the bundle, a new autoscaler targets it. Examples… loads ready-made bundles. Paste YAML… loads manifests (several, separated by ---, or a kind: List from kubectl get -o yaml) into the form, dropping status and server-set metadata.

For workloads the form covers the containers (pick one, or add a sidecar or init container): image, command and args, ports, environment — a value can be secret:NAME/KEY, configmap:NAME/KEY, field:metadata.name or resource:limits.memory — requests and limits with the resulting QoS class, the three probes, volumes and mounts, the security context, and pod settings such as the service account, node selector and tolerations. While Keep the pod labels and the selector in step is ticked, editing the labels also updates the pod template’s labels and spec.selector.

The YAML on the right updates as you type, for this object or the whole bundle. Click any line — or a ? beside a field — to read that field’s documentation, as kubectl explain prints it. Checks lists errors (what the API server would reject: a selector that does not match the template, a probe on a port name the container lacks, a CPU request above its limit, memory written as 128m, a CronJob name over 52 characters, a day of week of 7), warnings and, when ticked, tips — and checks across the bundle: a Service whose selector matches no pod or whose targetPort name does not exist, an Ingress backend port the Service lacks, an autoscaler using CPU utilization on containers with no CPU request. Click a finding to jump to the field. Lint in devops-yaml opens the bundle in the Compose and Kubernetes checker.

⛶ Full screen (or F when you are not typing) gives the Build form and the YAML the whole screen, side by side (stacked on a phone), each scrolling on its own — the browser’s full screen where it is allowed, otherwise a full-window layer (iPhone). Escape leaves.

Explain browses the field docs for a kind: click into fields as with kubectl explain deployment.spec.template.spec, or search names and descriptions. The docs are a subset of the OpenAPI spec of Kubernetes v1.37.1 (api/openapi-spec/swagger.json): every field of the kinds above except status, managedFields, ephemeral containers and deprecated volume plugins, with long descriptions shortened. They load on first use.

Units & QoS converts and checks a quantity: CPU in cores or millicores (0.5 = 500m), memory and storage in bytes and in decimal (k, M, G) and binary (Ki, Mi, Gi) units, and catches the usual mistakes (128m, 1GB, 512 Mi). 1G is 1,000,000,000 bytes; 1Gi is 1,073,741,824. The QoS calculator takes the requests and limits of each container and names the class the pod gets, following Kubernetes' own rules: requests default to limits; Guaranteed needs CPU and memory limits on every container equal to the requests; BestEffort has no CPU or memory requests or limits at all; everything else is Burstable.

Probes draws a timeline of a startup, readiness or liveness probe: when checks run, how long a failure takes to act on, and what happens then (removed from endpoints, or restarted). It uses the kubelet’s defaults for anything left out.

Schedule explains a CronJob schedule in words and lists the next ten runs in any time zone. It follows the CronJob controller’s parser (robfig/cron): five fields, day of week 0–6, ? as *, the @daily-style macros, and the rule that when both day fields are restricted a day matches if either does.

Related: Compose, Kubernetes and cron checker, kubectl helper (commands, selectors, JSONPath, RBAC), container dashboard, cron expression tool, YAML and JSON converter.

Share link copies a link to what the open tab shows. On Build that is the bundle (packed into ?s=, Secret values removed), or ?example=… while it is an unchanged example. Put the tab after #: build, explain, units, probes or schedule.

More: ?q=1G&res=memory#units (1G versus 1Gi), ?probe=startup&period=10&failure=30#probes (a 300-second start budget), ?cron=0 0 1 (the day-of-month OR day-of-week rule), ?kind=Deployment&field=spec.strategy.rollingUpdate#explain.