Override the defaults

This guide shows you how to change the package defaults for a single cluster without restating the whole configuration. The DefaultableConfig groups, versions, retention, storage, replicas, and resources, all ship with values in DEFAULT_CONFIG. mergeConfig deep-merges your input over them, so you set only the keys you want to change.

How the deep-merge works

mergeConfig accepts a MonitoringConfigInput, which is the required cluster values plus a DeepPartial of the defaultable groups. For each defaultable group, it merges your partial over the default at every nesting level. Keys you omit keep their default value.

This means a single nested key is enough. You do not need to repeat the surrounding object.

Override resources for one component

Raise the Prometheus memory limit and leave every other resource at its default.

const config = mergeConfig({
  // required cluster values ...
  resources: {
    prometheus: {
      limits: { memory: '6000Mi' },
    },
  },
});

Only resources.prometheus.limits.memory changes. The Prometheus CPU limit, its requests, and every other component keep their defaults.

Override retention

Keep raw metrics longer and shorten log retention.

const config = mergeConfig({
  // required cluster values ...
  retention: {
    prometheusS3Raw: 60,
    loki: '336h',
  },
});

Override storage and replicas

Grow the Prometheus volume and run a single Alertmanager for a small cluster.

const config = mergeConfig({
  // required cluster values ...
  storage: { prometheus: '30Gi' },
  replicas: { alertmanager: 1 },
});

Use another storage class

Every PVC of the stack requests the StorageClass named longhorn by default. Set storage.className to the class your cluster provides, or to an empty string to use the cluster’s default class.

const config = mergeConfig({
  // required cluster values ...
  storage: { className: 'fast-ssd' },
});

Set the class before the first deployment. On a running stack, the existing PVCs keep their class; only PVCs created afterward use the new one.

Pin a chart version

The versions group accepts either a pinned version or the string latest. Pin a chart to a known-good release.

const config = mergeConfig({
  // required cluster values ...
  versions: { loki: '7.0.0' },
});

When a version is latest, the construct omits the version field and lets the Helm controller resolve the newest chart.

Important

Pin chart and image versions for any cluster you care about reproducing. Leaving a version at latest makes the synthesized output depend on when the Helm controller runs.

Next steps

• Configuration options — the complete list of fields and defaults.

See also

• Retention and downsampling — how the retention values relate.