fix: emit CH_* ClickHouse connection keys in the clickhouse chart

[NitinKumar004]

Description

The ClickHouse chart's per-service connection ConfigMap/Secret emitted MySQL-style DB_* keys, which the consuming service doesn't read — so an app attaching to this chart got no usable connection.

This switches them to the CH_* keys the service reads (which it combines into GoFr's ClickHouse Hosts, see gofr.dev/docs/datasources/clickhouse):

Key	Location	Value
CH_HOST	ConfigMap	<release>-clickhouse
CH_PORT	ConfigMap	9000 (native TCP)
CH_USER	ConfigMap	provisioned user
CH_DATABASE	ConfigMap	the database
CH_PASSWORD	Secret	provisioned password

The consumer forms CH_HOST:CH_PORT as GoFr's Hosts. CH_USER lives in the ConfigMap (not sensitive); CH_PASSWORD in the Secret. Upgrade-preservation reads CH_USER from the existing ConfigMap and CH_PASSWORD from the existing Secret, so credentials stay stable across upgrades.

Chart bumped to v0.0.2, re-packaged, index regenerated.

Type of Change

• Bug fix (connection keys didn't match the consuming service)

Testing (local minikube)

With services: [{name: aggregator, database: zopnight_aggregator}]:

init pod: Succeeded
ConfigMap: CH_HOST=ch-clickhouse  CH_PORT=9000  CH_USER=aggregator_vuzo  CH_DATABASE=zopnight_aggregator
Secret keys: CH_PASSWORD
GoFr Hosts (CH_HOST:CH_PORT): ch-clickhouse:9000
connect with CH_USER/CH_PASSWORD/CH_DATABASE -> aggregator_vuzo
helm upgrade -> CH_USER preserved, CH_PASSWORD preserved

• helm lint passes; docs/index.yaml digest matches docs/clickhouse-v0.0.2.tgz

Checklist

• helm lint passes
• Verified end-to-end on a local cluster (incl. upgrade preservation)
• README Connection Config updated

[NitinKumar004]

Added upgrade-safety in 560362f: the credential-preservation lookup now falls back to the legacy DB_USER/DB_PASSWORD secret keys, so upgrading an existing release across the DB_*→GoFr key rename preserves the generated user/password (no rotation, no orphaned ClickHouse user).

Verified on minikube: installed published v0.0.1 (DB_* keys) → upgraded to this v0.0.2 → same user/password preserved and the original user still authenticates (currentUser()=aggregator_l0or, currentDatabase()=zopnight_aggregator).

[arunesh-j]

LGTM ✅

Fixes the connection-key mismatch from v0.0.1 (emitted MySQL-style DB_* keys that the consuming ClickHouse service doesn't read):

• ConfigMap now emits CH_HOST / CH_PORT / CH_USER / CH_DATABASE; Secret emits CH_PASSWORD. No lingering DB_* refs.
• Upgrade-preservation is correct for the new layout: CH_USER read back from the existing ConfigMap (plaintext), CH_PASSWORD from the existing Secret (b64dec); init SQL uses the same $username/$password.
• Object names are unchanged, so the #288 envFrom wiring keeps working.
• helm lint passes; version bumped 0.0.1 → 0.0.2; packaging correct (docs/clickhouse-v0.0.2.tgz digest matches index.yaml: 2681560f…).

Note (non-blocking): the CH_* names are a contract with the consuming service code (outside this repo) — GoFr's public docs example uses unprefixed HOSTS/USERNAME/PASSWORD/DATABASE, so worth a final confirm that the service template reads CH_* and joins CH_HOST:CH_PORT into GoFr's Hosts.

Approving.