chart: make replicas, livenessProbe, and readinessProbe configurable#1644
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teemow wants to merge 1 commit into
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chart: make replicas, livenessProbe, and readinessProbe configurable#1644teemow wants to merge 1 commit into
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The chart hardcoded `replicas: 1` and the liveness/readiness probe
parameters in the Deployment template, with no values knob to override
them. That worked when Backstage installs were small and a 10s
initialDelaySeconds liveness was generous, but plugin-heavy installs
(BWI portal, etc.) take 60-120s to register all plugins on a cold
start and get killed mid-init by the default liveness; operators
working around this had no choice but to hand-patch the live
Deployment after every chart upgrade, which is reverted on the next
HelmRelease reconcile.
Add three new value knobs:
- `replicas` (integer, default 1) -- the same default as before; only
safe to bump when backing the install with an RWX volume or
external Postgres database. Documented on the value.
- `readinessProbe` (object, default {}) -- merged over the chart's
default readiness probe, so callers can override individual fields
(e.g. just `initialDelaySeconds`) without restating the entire
probe shape.
- `livenessProbe` (object, default {}) -- same merge semantics for
the liveness probe.
Defaults are unchanged so existing installs render identically.
Co-authored-by: Cursor <cursoragent@cursor.com>
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The chart hardcoded
replicas: 1and the liveness/readiness probe parameters in the Deployment template, with no values knob to override them.That worked when Backstage installs were small and a 10s
initialDelaySecondsliveness was generous, but plugin-heavy installs (BWI portal, etc.) take 60-120s to register all plugins on a cold start and get killed mid-init by the default liveness. Operators working around this had no choice but to hand-patch the live Deployment after every chart upgrade -- which is reverted on the next HelmRelease reconcile.Changes
replicas(integer, default 1). Same default as before; only safe to bump when backing the install with an RWX volume or external Postgres database. Documented on the value.readinessProbe(object, default{}). Merged over the chart's default readiness probe viamergeOverwrite, so callers can override individual fields (e.g. justinitialDelaySeconds) without restating the entire probe shape.livenessProbe(object, default{}). Same merge semantics.Defaults are unchanged so existing installs render identically.
Verification
helm lint helm/backstagecleanhelm template ... --set replicas=2 --set livenessProbe.initialDelaySeconds=120 --set livenessProbe.failureThreshold=10 --set readinessProbe.initialDelaySeconds=60renders the expected Deployment withreplicas: 2, the chart's defaulthttpGetprobe paths/ports preserved, and the overridden timing fields applied.Why now
The BWI bundle (
giantswarm/bwibwi-backstage) ships an SQLite-PVC-backed Backstage and reconciles via Flux. Every bundle release reverts hand-patched probe overrides on the live Deployment, and Backstage's plugin-heavy cold start exceeds the default 10s liveness, leaving the new pod inCrashLoopBackOff. With these knobs the bundle can setlivenessProbe.initialDelaySeconds: 120, failureThreshold: 10andreadinessProbe.initialDelaySeconds: 60, failureThreshold: 20once and have it survive reconciliation.Made with Cursor