[network metrics] instance network interface schema

This is related to the ongoing work in [plumbing instance/guest
metrics](oxidecomputer/propolis#742) through to an
oximeter producer in propolis.

Includes:
- Rewriting the comment for `trait Target` in Oximeter to not being prepped for deprecation,
  as it does come in handy for custom needs
- The main differentiating field among instance network information here is `interface_id`, which is
  exposed to propolis via the client's `NetworkInterfaceRequest`. We currently match the `nic.slot` to the `port.slot` to pass which of the
  requested nics `interface_id` uuids are part of the request.

illumos-utils/src/opte/illumos.rs

@@ -56,6 +56,9 @@ pub enum Error {
 
     #[error("Can't attach new ephemeral IP {0}, currently have {1}")]
     ImplicitEphemeralIpDetach(IpAddr, IpAddr),
+
+    #[error("No matching NIC found for port {0} at slot {1}.")]
+    NoNicforPort(String, u32),
 }
 
 /// Delete all xde devices on the system.

oximeter/instruments/src/kstat/link.rs

@@ -19,7 +19,7 @@ use oximeter::Sample;
 
 oximeter::use_timeseries!("sled-data-link.toml");
 
-// Helper function to extract the same kstat metrics from all link targets.
+/// Helper function to extract the same kstat metrics from all link targets.
 fn extract_link_kstats<T>(
     target: &T,
     named_data: &Named,

oximeter/oximeter/schema/instance-network-interface.toml

@@ -0,0 +1,70 @@
+format_version = 1
+
+[target]
+name = "instance_network_interface"
+description = "A network interface attached to a virtual machine instance"
+authz_scope = "project"
+versions = [
+    { version = 1, fields = [ "interface_id", "instance_id", "project_id", "silo_id" ] },
+]
+
+[fields.interface_id]
+type = "uuid"
+description = "The ID of the network interface"
+
+[fields.instance_id]
+type = "uuid"
+description = "The ID of the virtual machine instance this network interface is attached to"
+
+[fields.project_id]
+type = "uuid"
+description = "The ID of the project containing the virtual machine instance this network interface is attached to"
+
+[fields.silo_id]
+type = "uuid"
+description = "The ID of the silo containing the virtual machine instance this network interface is attached to"
+
+[[metrics]]
+name = "bytes_sent"
+description = "Total number of bytes sent on the network interface"
+units = "bytes"
+datum_type = "cumulative_u64"
+versions = [
+    { added_in = 1, fields = [] }
+]
+
+[[metrics]]
+name = "bytes_received"
+description = "Total number of bytes received on the network interface"
+units = "bytes"
+datum_type = "cumulative_u64"
+versions = [
+    { added_in = 1, fields = [] }
+]
+
+[[metrics]]
+name = "packets_sent"
+description = "Total number of packets sent on the network interface"
+units = "count"
+datum_type = "cumulative_u64"
+versions = [
+    { added_in = 1, fields = [] }
+]
+
+[[metrics]]
+name = "packets_received"
+description = "Total number of packets received on the network interface"
+units = "count"
+datum_type = "cumulative_u64"
+versions = [
+    { added_in = 1, fields = [] }
+]
+
+[[metrics]]
+name = "packets_dropped"
+description = "Number of packets dropped on the RX queue of the network interface"
+units = "count"
+datum_type = "cumulative_u64"
+versions = [
+    { added_in = 1, fields = [] }
+]

oximeter/types/src/traits.rs

@@ -23,12 +23,14 @@ use std::num::NonZeroU8;
 use std::ops::Add;
 use std::ops::AddAssign;
 
-/// The `Target` trait identifies a source of metric data by a sequence of fields.
-///
-/// A target is a single source of metric data, identified by a sequence of named and typed field
-/// values. Users can write a single struct definition and derive this trait. The methods here
-/// provide some introspection into the struct, listing its fields and their values. The struct
-/// definition can be thought of as a schema, and an instance of that struct as identifying an
+/// The `Target` trait identifies a source of metric data by a sequence of
+/// fields.
+///
+/// A target is a single source of metric data, identified by a sequence of
+/// named and typed field values. Users can write a single struct definition and
+/// derive this trait. The methods here provide some introspection into the
+/// struct, listing its fields and their values. The struct definition can be
+/// thought of as a schema, and an instance of that struct as identifying an
 /// individual target.
 ///
 /// Target fields may have one of a set of supported types:
@@ -85,10 +87,11 @@ use std::ops::AddAssign;
 /// }
 /// ```
 ///
-/// **Important:** Deriving this trait is deprecated, and will be removed in the
-/// future. Instead, define your timeseries schema through the TOML format
-/// described in [the crate documentation](crate), and use the code
-/// generated by the `use_timeseries` macro.
+/// **Important:** Typically, you should define your timeseries schema through
+/// the TOML format described in [the crate documentation](crate), and use the
+/// code generated by the `use_timeseries` macro. However, if you need to handle
+/// custom sampling logic and must define custom field definitions not published
+/// as part of the target schema, you can implement this trait.
 pub trait Target {
     /// Return the name of the target, which is the snake_case form of the struct's name.
     fn name(&self) -> &'static str;

sled-agent/src/instance.rs

@@ -676,11 +676,28 @@ impl InstanceRunner {
     ) -> Result<(), Error> {
         let nics = running_zone
             .opte_ports()
-            .map(|port| propolis_client::types::NetworkInterfaceRequest {
-                name: port.name().to_string(),
-                slot: propolis_client::types::Slot(port.slot()),
+            .map(|port| {
+                self.requested_nics
+                    .iter()
+                    // We expect to match NIC slots to OPTE port slots.
+                    // Error out if we can't find a NIC for a port.
+                    .position(|nic| nic.slot == port.slot())
+                    .ok_or(Error::Opte(
+                        illumos_utils::opte::Error::NoNicforPort(
+                            port.name().into(),
+                            port.slot().into(),
+                        ),
+                    ))
+                    .map(|pos| {
+                        let nic = &self.requested_nics[pos];
+                        propolis_client::types::NetworkInterfaceRequest {
+                            interface_id: nic.id,
+                            name: port.name().to_string(),
+                            slot: propolis_client::types::Slot(port.slot()),
+                        }
+                    })
             })
-            .collect();
+            .collect::<Result<Vec<_>, _>>()?;
 
         let migrate = match migrate {
             Some(params) => {