kestrel(agent)

Kestrel is the in-guest agent and default PID1 for initramfs default mode.

Key behavior (see fledge/internal/builder/embed/init.c and agent code):

When used as PID1, it prepares the guest environment and exposes a control socket over vsock.

It can proxy HTTP requests from volantd to workloads running in the guest, enabling fully isolated vsock-only deployments.

The agent receives runtime arguments via the kernel cmdline, encoded by the orchestrator, including:

runtime (pluginspec.RuntimeKey)

api host/port (pluginspec.APIHostKey/APIPortKey)

encoded manifest (pluginspec.CmdlineKey)

For most users, there are no CLI flags to pass directly to kestrel; configuration is provided through the manifest and per-VM config.