Move cloud specific logic out of plugins

[reubenmiller]

Is your feature request related to a problem? Please describe.

The following plugins assume that the cloud backend is Cumulocity IoT.

• c8y-log-plugin
• c8y-configuration-plugin
• c8y-firmware-plugin (a PoC of this conversion can be seen here)

It would be very beneficial (and a cleaner overall design) if all cloud specific logic was moved out of the plugins and to the associated mappers. This would leave a plugin that could be usable for different clouds. A good reference is the Software Management feature in the tedge-agent which provides tedge/commands topics to handle requests and responses related software management in a cloud agnostic manner.

Describe the solution you'd like

The following points should be covered:

• Move cloud specific logic from the non-mapper plugins (e.g. c8y-*) to the mapper
• Rename the c8y-* plugins to tedge-* once all cloud specific logic has been moved. Ignore the c8y-firmware-plugin as it will be migrated at a later point in time.

Describe alternatives you've considered

Additional context

One specific challenged that will need to be addressed is how to handle cloud specific HTTP downloads/uploads. As this generally requires a cloud specific authorization. The actual implementation of a cloud specific downloader/uploader could be implemented in a different issue/PR and then used by this issue.

This is also related to the topic of subscribing to Cumulocity JSON operations via the devicecontrol/notifications #1718 topic which sends the operations as JSON instead of Cumulocity SmartREST.

Subtasks

• Add root.topic and device.topic to tedge config Add mqtt.topic_root and mqtt.device_topic_id options #2231
• Make log plugin usable for different clouds #2048
• Make configuration plugin usable for different clouds #2098
• tedge-firmware-plugin -> Postpone, as it needs more refinement how to support firmware installation itself (exact command to install firmware, reboot, ...)

[reubenmiller]

The following plugins have been migrated to a generic implementation with no cloud-specific logic:

• c8y-configuration-plugin -> tedge-configuration-plugin
• c8y-log-plugin -> tedge-log-plugin

The system tests have been updated to use the these new plugins.

• tedge-configuration-plugin
  • configuration_operation.robot
• tedge-log-plugin
  • log_operation.robot
  • log_operation_child.robot

[reubenmiller]

QA has thoroughly checked the feature and here are the results:

• Test for ticket exists in the test suite.
• QA has tested the bug and could not reproduce it anymore.