What does this PR do?

Adds DD_GENERIC_RESOURCE_FORCE_SYNC_PERIOD to configure the DatadogGenericResource force-sync interval, matching the existing monitor/dashboard/SLO behavior. The value is resolved once when the DDGR controller starts, logged at info level, and reused during reconciliation.

The configured value must be at least one minute. Non-integer values, 0, and negative values are rejected once during controller startup and fall back to the default 60-minute force-sync period.

Also documents DDGR force sync and the existing DDGR namespace watch environment variable.

Motivation

DatadogGenericResource already force-syncs remote resources every 60 minutes, but unlike related Datadog resource controllers, the interval was not configurable. This makes DDGR behavior easier to tune and easier to validate when remote resources drift from Kubernetes source of truth.

Rejecting values below one minute avoids surprising behavior where 0 or negative durations would force an update on every reconciliation loop.

Additional Notes

DD_GENERIC_RESOURCE_WATCH_NAMESPACE already existed and falls back to WATCH_NAMESPACE; this PR only documents that behavior.

The reconcile tests construct the DDGR reconciler through NewReconciler and then override the resource handlers with mocks, so the production force-sync initialization path is covered without calling real Datadog APIs.

Minimum Agent Versions

Are there minimum versions of the Datadog Agent and/or Cluster Agent required?

• Agent: N/A
• Cluster Agent: N/A

Describe your test plan

Automated validation:

go test -count=1 ./internal/controller/datadoggenericresource

The tests cover valid force-sync configuration, invalid string values, 0, negative values, and an elapsed force-sync period triggering a remote update.

Manual QA:

1. Start the operator with the DDGR controller enabled and an invalid force-sync period:

   DD_GENERIC_RESOURCE_FORCE_SYNC_PERIOD=abc

   Verify the operator logs contain this error once during controller startup:

   {"level":"ERROR","logger":"controllers.DatadogGenericResource","msg":"Invalid value for generic resource force sync period. Defaulting to 60 minutes.","error":"strconv.Atoi: parsing \"abc\": invalid syntax"}

2. Restart the operator with a valid five-minute force-sync period:

   DD_GENERIC_RESOURCE_FORCE_SYNC_PERIOD=5

   Verify the operator logs contain this info log during controller startup:

   {"level":"INFO","logger":"controllers.DatadogGenericResource","msg":"Setting generic resource force sync period","minutes":5}

3. Apply the notebook DDGR sample:

   kubectl apply -f examples/datadoggenericresource/notebook-sample.yaml

   Wait for the resource to be created and record the Datadog notebook ID:

   kubectl get datadoggenericresource ddgr-notebook-sample -o jsonpath='{.status.id}'

4. In the Datadog UI, open that notebook and make a visible edit, for example change the notebook name from Example-Notebook to Example-Notebook edited from UI.

5. Wait at least five minutes, then verify the operator force-sync restored the notebook to the Kubernetes spec from examples/datadoggenericresource/notebook-sample.yaml, including the original notebook name Example-Notebook.

6. Clean up the sample resource:

   kubectl delete -f examples/datadoggenericresource/notebook-sample.yaml

Checklist

• PR has at least one valid label: bug, enhancement, refactoring, documentation, tooling, and/or dependencies
• PR has a milestone or the qa/skip-qa label
• All commits are signed (see: signing commits)