Files
netbird/proxy/internal/middleware/builtin/cost_meter/factory.go

99 lines
3.5 KiB
Go

package cost_meter
import (
"bytes"
"encoding/json"
"fmt"
"github.com/netbirdio/netbird/proxy/internal/llm/pricing"
"github.com/netbirdio/netbird/proxy/internal/middleware"
"github.com/netbirdio/netbird/proxy/internal/middleware/builtin"
)
// Config is the on-wire configuration for the middleware, synthesized by
// management (buildCostMeterConfigJSON). The proxy has no embedded price
// list: this payload is the only pricing source, and updates arrive as
// ordinary mapping pushes that rebuild the chain (and with it this
// middleware instance) — no per-request fetches, no reload loops.
type Config struct {
Pricing *PricingConfig `json:"pricing"`
}
// PricingConfig carries the full pricing table:
// - Defaults: parser surface ("openai"/"anthropic"/"bedrock") ->
// normalized model id -> rates, matched against llm.provider +
// llm.model.
// - Providers: provider record id -> normalized model id -> rates,
// matched against the llm.resolved_provider_id metadata llm_router
// stamps. Entries arrive fully materialized (management folds default
// cache rates in at synth time), so lookup order is simply
// per-record first, defaults second.
type PricingConfig struct {
Defaults map[string]map[string]pricing.EntryJSON `json:"defaults"`
Providers map[string]map[string]pricing.EntryJSON `json:"providers"`
}
// Factory builds cost_meter instances from raw config bytes.
type Factory struct{}
// ID returns the registry identifier.
func (Factory) ID() string { return ID }
// New constructs a middleware instance. Empty, null, and {} configs are
// accepted for backward compatibility with a management server that
// predates config-delivered pricing — the instance then skips every cost
// computation (unknown_model) and a warning is logged once at build time.
// Non-empty rawConfig that fails to unmarshal, or a table carrying a
// non-finite / negative rate, is rejected so misconfigurations surface at
// chain build time.
func (Factory) New(rawConfig []byte) (middleware.Middleware, error) {
cfg, err := decodeConfig(rawConfig)
if err != nil {
return nil, err
}
if cfg.Pricing == nil {
if logger := builtin.Context().Logger; logger != nil {
logger.Warnf("cost_meter: no pricing table in middleware config; management predates config-delivered pricing — every request will record cost.skipped=unknown_model ($0)")
}
return newMiddleware(mustEmptyTable(), nil), nil
}
defaults, err := pricing.NewTable(cfg.Pricing.Defaults)
if err != nil {
return nil, fmt.Errorf("cost_meter pricing defaults: %w", err)
}
perRecord, err := pricing.NewEntries(cfg.Pricing.Providers)
if err != nil {
return nil, fmt.Errorf("cost_meter per-provider pricing: %w", err)
}
return newMiddleware(defaults, perRecord), nil
}
// mustEmptyTable returns a valid empty table. NewTable on a nil map cannot
// fail; the panic guard documents that invariant.
func mustEmptyTable() *pricing.Table {
t, err := pricing.NewTable(nil)
if err != nil {
panic(fmt.Sprintf("cost_meter: empty pricing table must build: %v", err))
}
return t
}
// decodeConfig accepts empty, null, and {} configs, returning a
// zero-value Config. Non-empty payloads must parse cleanly.
func decodeConfig(rawConfig []byte) (Config, error) {
var cfg Config
if len(bytes.TrimSpace(rawConfig)) == 0 {
return cfg, nil
}
if err := json.Unmarshal(rawConfig, &cfg); err != nil {
return cfg, fmt.Errorf("decode config: %w", err)
}
return cfg, nil
}
func init() {
builtin.Register(Factory{})
}