Diagnostics

Step 9 turns vine into an operator-facing tool instead of a Zig-only runtime.

The current diagnostics commands are:

• vine status
• vine peers
• vine routes
• vine sessions
• vine counters
• vine snapshot
• vine ping <overlay-ip>

These commands are config-driven and are meant to answer different questions:

• status: is the node configured correctly and what overlay identity is it using?
• peers: which peers and prefixes are configured?
• routes: which overlay prefixes point at which peers?
• sessions: which session class is preferred for each peer?
• counters: are packets failing, missing routes, or falling back to relay?
• snapshot: dump the major sections together
• ping: which peer and session would carry traffic to a given overlay IP?

Diagnostics support two explicit output modes:

• --format text
• --format json

Use text for shell-driven inspection and JSON for machine parsing.

The counters surface currently includes:

• packets_sent
• packets_received
• route_misses
• session_failures
• fallback_transitions
• relay_usage

relay_usage is especially useful when a deployment is technically working but direct paths are not being selected as often as expected.

Example:

vine status --format text -c /etc/libvine/vine.toml
vine sessions --format json -c /etc/libvine/vine.toml
vine ping --format text -c /etc/libvine/vine.toml 10.42.9.7

This is still a lightweight diagnostics layer, but it is now good enough to inspect peer ownership, route intent, preferred transport paths, and relay dependence without reading the Zig code.