The data shipper must be runnable by the Elastic agent. This issue captures the shipper side work for elastic/elastic-agent#214.

The shipper executable must implement the Elastic agent V2 control protocol, defined here: https://github.com/elastic/elastic-agent-client. Note that the control protocol is being updated as part of the Agent V2 architecture in elastic/elastic-agent-client#29. The control protocol features to be implemented must be coordinated with the control plane team.

While we should use the V2 protocol in the final version of the shipper, initial prototyping can be done using the V1 implementation to unblock progress while the control plane team finalizes the V2 protocol:

• Prototype running the shipper under agent using the V1 protocol #46
• Provide the relevant subset of the agent policy to the shipper as its configuration elastic-agent#617

This issue is considered complete when:

• A test proves that the Elastic agent can successfully start and monitor the data shipper, including logs, metrics, and runtime health.
• A test proves that the Elastic agent can upgrade the data shipper.
• A test proves that the Elastic agent can detect when the shipper is unhealthy or stopped.