feat: Apply orb policies

[jajeffries]

This pull request refactors the MQTT message handling logic in the Fleet configuration manager to improve modularity, testability, and separation of concerns. The primary change is the introduction of a new Messaging struct that encapsulates all message dispatching and handling logic, decoupling it from the core MQTT connection code. This also results in updated method signatures, improved dependency injection (notably for the policy manager), and more comprehensive unit tests with mock implementations.

Refactoring and Modularity Improvements:

• Introduced a new Messaging struct in from_rpc.go to handle all MQTT message dispatching and processing, moving logic out of MQTTConnection and improving separation of concerns. The Messaging struct now manages group membership and agent policy messages, and is injected with a PolicyManager dependency for better testability and modularity.
• Updated MQTTConnection to include a messaging field and delegate message-related logic (capabilities, group memberships, and policy updates) to the Messaging struct. This includes changes to the constructor and method signatures to pass the PolicyManager and agent ID where needed. [1] [2] [3] [4] [5]

API and Interface Changes:

• Changed the signature of NewMQTTConnection to require a PolicyManager and updated all usages accordingly. The Connect method now also takes the agentID as a separate parameter and passes it through to message handlers. [1] [2] [3]
• Added new helper methods to MQTTConnection for subscribing and publishing to topics, which are now passed as function parameters to the message handlers for improved decoupling.

Testing Improvements:

• Added comprehensive mock implementations of the PolicyManager interface in both connection_test.go and from_rpc_test.go, enabling more robust and isolated unit tests for message handling logic. [1] [2]
• Updated existing tests to use the new Messaging struct and mock dependencies, ensuring that message dispatching and handler logic are properly exercised and validated. [1] [2] [3]

Other Notable Changes:

• Improved error handling and logging throughout the message dispatching process, including explicit logging for unknown message types and unmarshalling failures.
• Cleaned up imports and removed unused dependencies, such as encoding/json where no longer needed.

These changes collectively make the Fleet configuration manager's MQTT handling more modular, maintainable, and testable, laying the groundwork for future enhancements.

References:
[1] [2] [3] [4] [5] [6]

[github-actions]

Go test coverage

STATUS	ELAPSED	PACKAGE	COVER	PASS	FAIL	SKIP
🟢 PASS	0.01s	github.com/netboxlabs/orb-agent/agent	0.0%	0	0	0
🟢 PASS	0.01s	github.com/netboxlabs/orb-agent/agent/backend	0.0%	0	0	0
🟢 PASS	5.03s	github.com/netboxlabs/orb-agent/agent/backend/devicediscovery	76.0%	3	0	0
🟢 PASS	0.01s	github.com/netboxlabs/orb-agent/agent/backend/mocks	0.0%	0	0	0
🟢 PASS	8.04s	github.com/netboxlabs/orb-agent/agent/backend/networkdiscovery	76.2%	7	0	0
🟢 PASS	4.02s	github.com/netboxlabs/orb-agent/agent/backend/opentelemetryinfinity	75.9%	2	0	0
🟢 PASS	3.02s	github.com/netboxlabs/orb-agent/agent/backend/pktvisor	65.6%	2	0	0
🟢 PASS	8.04s	github.com/netboxlabs/orb-agent/agent/backend/snmpdiscovery	75.8%	7	0	0
🟢 PASS	5.03s	github.com/netboxlabs/orb-agent/agent/backend/worker	76.0%	3	0	0
🟢 PASS	1.01s	github.com/netboxlabs/orb-agent/agent/config	100.0%	6	0	0
🟢 PASS	31.18s	github.com/netboxlabs/orb-agent/agent/configmgr	51.5%	13	0	0
🟢 PASS	4.41s	github.com/netboxlabs/orb-agent/agent/configmgr/fleet	54.3%	54	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	31.77s	github.com/netboxlabs/orb-agent/agent/secretsmgr	48.9%	54	0	0
🟢 PASS	1.01s	github.com/netboxlabs/orb-agent/agent/version	100.0%	1	0	0

Total coverage: 58.8%

[github-actions]

🎉 This PR is included in version 2.5.0 🎉

The release is available on GitHub release

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[github-actions]

🎉 This PR is included in version 2.5.0 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀