Generated best practices file (#1592)

Co-authored-by: qodo-merge-pro[bot] <151058649+qodo-merge-pro[bot]@users.noreply.github.com>

Author: qodo-code-review[bot]

best_practices.md

@@ -0,0 +1,164 @@
+
+<b>Pattern 1: Add complete, runnable examples in docs and example manifests by including required dependent resources (for example, Secrets or CRDs) with safe placeholder values so users can apply them out-of-the-box.</b>
+
+Example code before:
+```
+# examples/orchestrator.yaml
+apiVersion: rhdh.redhat.com/v1alpha4
+kind: Backstage
+metadata:
+  name: orchestrator
+spec:
+  application:
+    extraEnvs:
+      secrets:
+        - name: backend-auth-secret
+# Secret referenced above is missing
+```
+
+Example code after:
+```
+# examples/orchestrator.yaml
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: backend-auth-secret
+stringData:
+  BACKEND_SECRET: "dummy-not-secret"
+---
+apiVersion: rhdh.redhat.com/v1alpha4
+kind: Backstage
+metadata:
+  name: orchestrator
+spec:
+  application:
+    extraEnvs:
+      secrets:
+        - name: backend-auth-secret
+```
+
+<details><summary>Examples for relevant past discussions:</summary>
+
+- https://github.com/redhat-developer/rhdh-operator/pull/1567#discussion_r2315417933
+- https://github.com/redhat-developer/rhdh-operator/pull/1219#discussion_r2163204987
+</details>
+
+
+___
+
+<b>Pattern 2: When introducing optional features controlled by CR fields, implement idempotent create-or-update logic, register required schemes, add RBAC, and gate behavior on CRD presence; also document enabling/disabling and lifecycle management.</b>
+
+Example code before:
+```
+// creates ServiceMonitor with server-side apply (SSA)
+err := c.Patch(ctx, sm, client.Apply, applyOpts)
+// no scheme registration or RBAC for ServiceMonitor
+```
+
+Example code after:
+```
+// register monitoring v1 scheme and add RBAC for servicemonitors
+controllerutil.CreateOrUpdate(ctx, c, sm, func() error {
+  sm.Spec = desiredSpec
+  return controllerutil.SetControllerReference(owner, sm, scheme)
+})
+// check CRD exists if needed; reconcile create/update/delete on spec.monitoring.enabled
+```
+
+<details><summary>Examples for relevant past discussions:</summary>
+
+- https://github.com/redhat-developer/rhdh-operator/pull/1374#discussion_r2248149438
+- https://github.com/redhat-developer/rhdh-operator/pull/1374#discussion_r2253372015
+- https://github.com/redhat-developer/rhdh-operator/pull/1499#discussion_r2284826017
+</details>
+
+
+___
+
+<b>Pattern 3: Preserve autoscaling compatibility by omitting or commenting out hard-coded replicas in Deployment/StatefulSet templates and add explicit comments explaining the omission.</b>
+
+Example code before:
+```
+spec:
+  replicas: 1
+  template:
+    spec: {}
+```
+
+Example code after:
+```
+spec:
+  # replicas: 1  # Intentionally omitted to allow HPA or custom scaling control.
+  template:
+    spec: {}
+```
+
+<details><summary>Examples for relevant past discussions:</summary>
+
+- https://github.com/redhat-developer/rhdh-operator/pull/1284#discussion_r2156758328
+- https://github.com/redhat-developer/rhdh-operator/pull/1284#discussion_r2157238898
+</details>
+
+
+___
+
+<b>Pattern 4: Keep documentation synchronized with implementation changes, specifying versions, defaults, namespaces, and merge semantics to avoid user confusion when behavior evolves.</b>
+
+Example code before:
+```
+# docs/configuration.md
+From version 0.7.0, dynamic plugins are overridden by the CR.
+```
+
+Example code after:
+```
+# docs/configuration.md
+Before 0.8.0 the Operator replaced defaults; since 0.8.0 it merges defaults with the user ConfigMap (non-deep merge).
+Resources are created in the same namespace as the Backstage CR unless stated otherwise.
+```
+
+<details><summary>Examples for relevant past discussions:</summary>
+
+- https://github.com/redhat-developer/rhdh-operator/pull/1486#discussion_r2288776329
+- https://github.com/redhat-developer/rhdh-operator/pull/1551#discussion_r2301210631
+- https://github.com/redhat-developer/rhdh-operator/pull/1551#discussion_r2301214220
+- https://github.com/redhat-developer/rhdh-operator/pull/1323#discussion_r2179583371
+</details>
+
+
+___
+
+<b>Pattern 5: Harden shell scripts by enabling strict modes, quoting variables and arrays, validating required env vars, avoiding brittle traps, and removing unused variables to satisfy ShellCheck and prevent runtime errors.</b>
+
+Example code before:
+```
+#!/bin/bash
+for db in ${!allDB[@]}; do
+  echo Copying database: $db
+done
+trap "rm -f $tmpFile" EXIT
+```
+
+Example code after:
+```
+#!/bin/bash
+set -euo pipefail
+: "${TO_PSW:?TO_PSW environment variable not set}"
+for db in "${allDB[@]}"; do
+  echo "Copying database: ${db}"
+done
+trap 'rm -f "$tmpFile" || true' EXIT
+```
+
+<details><summary>Examples for relevant past discussions:</summary>
+
+- https://github.com/redhat-developer/rhdh-operator/pull/1305#discussion_r2175117965
+- https://github.com/redhat-developer/rhdh-operator/pull/1305#discussion_r2175123942
+- https://github.com/redhat-developer/rhdh-operator/pull/1305#discussion_r2175338254
+- https://github.com/redhat-developer/rhdh-operator/pull/1305#discussion_r2188582064
+- https://github.com/redhat-developer/rhdh-operator/pull/1305#discussion_r2188591953
+</details>
+
+
+___