feat: add openteletry metrics support for each backend

[leoparente]

This pull request introduces support for OpenTelemetry (OTLP) metrics endpoints across multiple backend components (deviceDiscoveryBackend, networkDiscoveryBackend, workerBackend, and pktvisorBackend). It replaces the previous host/port configuration for OTLP with HTTP and gRPC endpoint URLs, ensuring more flexibility and consistency in configuration. Key changes include adding new fields for OTLP endpoints, updating configuration logic, and modifying startup commands to include OTLP-related options.

OpenTelemetry (OTLP) Integration:

• Added a new diodeOtelEndpoint field to the deviceDiscoveryBackend, networkDiscoveryBackend, and workerBackend structs to store the gRPC OTLP endpoint. Updated their Configure methods to set this field based on the common.Otel.Grpc configuration and log the endpoint being used. Modified the Start methods to append the --otel-endpoint option to the startup arguments if the endpoint is configured. (device_discovery.go: [1] [2] [3]; network_discovery.go: [4] [5] [6]; worker.go: [7] [8] [9]

• Updated the pktvisorBackend to parse and validate the OTLP HTTP endpoint URL (common.Otel.HTTP) instead of using separate host and port fields. Extracted and logged the host and port from the URL during configuration. (pktvisor.go: [1] [2]

Configuration Schema Updates:

• Replaced the host and port fields in the BackendCommons.Otel configuration with grpc and http fields to support full endpoint URLs for OTLP metrics. (types.go: agent/config/types.goL71-R72)

[github-actions]

Go test coverage

STATUS	ELAPSED	PACKAGE	COVER	PASS	FAIL	SKIP
🟢 PASS	0.24s	github.com/netboxlabs/orb-agent/agent	0.0%	0	0	0
🟢 PASS	0.24s	github.com/netboxlabs/orb-agent/agent/backend	0.0%	0	0	0
🟢 PASS	4.03s	github.com/netboxlabs/orb-agent/agent/backend/devicediscovery	76.5%	2	0	0
🟢 PASS	0.01s	github.com/netboxlabs/orb-agent/agent/backend/mocks	0.0%	0	0	0
🟢 PASS	4.03s	github.com/netboxlabs/orb-agent/agent/backend/networkdiscovery	76.3%	2	0	0
🟢 PASS	4.02s	github.com/netboxlabs/orb-agent/agent/backend/otel	76.4%	2	0	0
🟢 PASS	3.02s	github.com/netboxlabs/orb-agent/agent/backend/pktvisor	65.6%	2	0	0
🟢 PASS	4.03s	github.com/netboxlabs/orb-agent/agent/backend/worker	72.8%	2	0	0
🟢 PASS	1.01s	github.com/netboxlabs/orb-agent/agent/config	100.0%	6	0	0
🟢 PASS	1.05s	github.com/netboxlabs/orb-agent/agent/configmgr	49.4%	9	0	0
🟢 PASS	1.01s	github.com/netboxlabs/orb-agent/agent/policies	100.0%	15	0	0
🟢 PASS	1.02s	github.com/netboxlabs/orb-agent/agent/policymgr	70.3%	10	0	0
🟢 PASS	2.49s	github.com/netboxlabs/orb-agent/agent/secretsmgr	45.7%	45	0	0
🟢 PASS	1.01s	github.com/netboxlabs/orb-agent/agent/version	100.0%	1	0	0

Total coverage: 59.7%

[jajeffries]

Looks good!