Helm Chart Work Guide

Working on the Astronomer APC Chart

APC is an umbrella chart: templates live at the umbrella level (under templates/ and charts/<chart>/templates/), sub-charts are tightly coupled and not intended to be used standalone, and a single values.yaml controls the entire platform. See docs/architecture.md for the installation modes (unified / control / data), per-mode component inventory, and cross-plane communication.

For testing, use the chart-tests skill — it covers render_chart(), sub-chart values nesting, parametrized tests, and uv run pytest usage.

Template layout

Three filename styles coexist in this repo. When adding a new template, follow whichever style the surrounding chart already uses — we do not retroactively rename existing files.

Style 1 — component-prefixed bare files. Used in single-component sub-charts: alertmanager, external-es-proxy, external-secrets, grafana, kube-state, pgbouncer, prometheus, vector. Filenames are <chart>[-feature]-<k8s_object>.yaml directly under templates/.

charts/alertmanager/templates/alertmanager-statefulset.yaml
charts/prometheus/templates/prometheus-alerts-configmap.yaml
charts/vector/templates/vector-daemonset.yaml