Feature request: Additive extraArgs for Velero server and node-agent

[kaovilai]

Problem

All three current mechanisms for configuring Velero server args are full overrides, not additive:

1. Operator defaults (Layer A) — built from individual DPA spec fields (logLevel, itemOperationSyncFrequency, resourceTimeout, etc.)
2. spec.configuration.velero.args (Layer B) — replaces ALL Layer A defaults. Code explicitly says "we are overriding args, so recreate args from scratch"
3. oadp.openshift.io/unsupported-velero-server-args annotation + ConfigMap (Layer C) — replaces everything from both Layer A and Layer B

Customers who need to add a single extra flag (e.g., a custom timeout or debug option) must reproduce the entire default args list in their override, which is fragile and version-dependent. If the operator adds new default flags in an upgrade, the customer's override silently drops them.

This gap was surfaced in OADP-7829 (support case 04410122).

Proposed solution

Add extraArgs field to VeleroConfig (and NodeAgentConfig for symmetry) that appends to the operator-computed defaults rather than replacing them:

spec:
  configuration:
    velero:
      extraArgs:
        some-custom-flag: "value"
        another-flag: "true"
    nodeAgent:
      extraArgs:
        some-node-agent-flag: "value"

Behavior

• extraArgs is applied after all operator defaults (and after args if set)
• If the same flag appears in both defaults and extraArgs, extraArgs value wins (last-writer-wins dedup by flag name)
• When the unsupported-args annotation is present, it still takes highest priority (existing behavior)
• extraArgs is a map[string]string — keys are flag names (without -- prefix), values are flag values

Implementation scope

• API: Add ExtraArgs map[string]string to VeleroConfig and NodeAgentConfig in api/v1alpha1/dataprotectionapplication_types.go
• Controller: Add mergeExtraArgs() helper called at end of customizeVeleroContainer() and node-agent equivalent
• Tests: Unit tests for merge logic, deduplication, and interaction with existing args field

Risks and mitigations

Risk	Mitigation
Duplicate flags	mergeExtraArgs deduplicates by flag name, extraArgs wins
Overriding operator-critical flags	Document which flags should not be overridden; optionally log warning
Interaction with args field	extraArgs applies after args, composable. Document precedence
Invalid flag names	Velero validates at startup (same as ConfigMap approach)

Note

Responses generated with Claude