llmgw/internal/config/config_test.go

package config

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"gitea.mynodes.xyz/ilker/llmgw/internal/control/catalog"
)

func write(t *testing.T, content string) string {
	t.Helper()
	p := filepath.Join(t.TempDir(), "server.yaml")
	if err := os.WriteFile(p, []byte(content), 0o600); err != nil {
		t.Fatal(err)
	}
	return p
}

func TestLoadDefaultsWithoutFile(t *testing.T) {
	cfg, err := Load("")
	if err != nil {
		t.Fatal(err)
	}
	if cfg.Listen != ":8080" || cfg.Router.DefaultProfile != "chat" {
		t.Errorf("defaults not applied: %+v", cfg)
	}
}

func TestLoadOverlaysOnDefaults(t *testing.T) {
	// Specifying one field must not blank out its neighbours.
	p := write(t, `
listen: ":9999"
endpoints:
  - id: a
    url: http://127.0.0.1:8000
    models: [m]
`)
	cfg, err := Load(p)
	if err != nil {
		t.Fatal(err)
	}
	if cfg.Listen != ":9999" {
		t.Errorf("listen=%q", cfg.Listen)
	}
	if cfg.Router.ScrapeInterval != 2*time.Second {
		t.Errorf("an unspecified default was lost: %v", cfg.Router.ScrapeInterval)
	}
	if len(cfg.Endpoints) != 1 || cfg.Endpoints[0].ID != "a" {
		t.Errorf("endpoints=%+v", cfg.Endpoints)
	}
}

func TestDurationsParse(t *testing.T) {
	p := write(t, `
router:
  scrape_interval: 500ms
  timeouts:
    idle: 45s
`)
	cfg, err := Load(p)
	if err != nil {
		t.Fatal(err)
	}
	if cfg.Router.ScrapeInterval != 500*time.Millisecond {
		t.Errorf("scrape_interval=%v", cfg.Router.ScrapeInterval)
	}
	if cfg.Router.Timeouts.Idle != 45*time.Second {
		t.Errorf("timeouts.idle=%v", cfg.Router.Timeouts.Idle)
	}
}

func TestEnvOverride(t *testing.T) {
	t.Setenv("LLMGW_ROUTER__RETRIES", "7")
	cfg, err := Load("")
	if err != nil {
		t.Fatal(err)
	}
	if cfg.Router.Retries != 7 {
		t.Errorf("retries=%d, expected the environment to win", cfg.Router.Retries)
	}
}

func TestMissingFileIsAnError(t *testing.T) {
	if _, err := Load("/nonexistent/server.yaml"); err == nil {
		t.Error("expected an error for a missing config file")
	}
}

func TestValidateRejectsBadEndpoints(t *testing.T) {
	cases := []struct {
		name string
		ep   Endpoint
		want string
	}{
		{"no id", Endpoint{URL: "http://x", Models: []string{"m"}}, "id is required"},
		{"no url", Endpoint{ID: "a", Models: []string{"m"}}, "url is required"},
		{"bad scheme", Endpoint{ID: "a", URL: "127.0.0.1:8000", Models: []string{"m"}}, "http://"},
		{"no models", Endpoint{ID: "a", URL: "http://x"}, "at least one model"},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			s := Default()
			s.Endpoints = []Endpoint{c.ep}
			err := s.Validate()
			if err == nil {
				t.Fatal("expected an error")
			}
			if !strings.Contains(err.Error(), c.want) {
				t.Errorf("error %q does not mention %q", err, c.want)
			}
		})
	}
}

func TestValidateRejectsDuplicateEndpointID(t *testing.T) {
	s := Default()
	s.Endpoints = []Endpoint{
		{ID: "a", URL: "http://x", Models: []string{"m"}},
		{ID: "a", URL: "http://y", Models: []string{"m"}},
	}
	if err := s.Validate(); err == nil || !strings.Contains(err.Error(), "twice") {
		t.Errorf("duplicate id not rejected: %v", err)
	}
}

func TestValidateRejectsAliasCollision(t *testing.T) {
	// An alias shadowing another model would silently misroute every request
	// for that model, so it has to fail at load time.
	s := Default()
	s.Models = []catalog.Model{
		{Name: "llama-3.3-70b", Source: "/m", Aliases: []string{"qwen"},
			Profiles: []catalog.Profile{{Name: "p", GPUClass: "h100-80g", TP: 1}}},
		{Name: "qwen", Source: "/m",
			Profiles: []catalog.Profile{{Name: "p", GPUClass: "h100-80g", TP: 1}}},
	}
	err := s.Validate()
	if err == nil || !strings.Contains(err.Error(), "collides") {
		t.Errorf("alias collision not rejected: %v", err)
	}
}

func TestValidateAcceptsDistinctAliases(t *testing.T) {
	s := Default()
	s.Models = []catalog.Model{
		{Name: "llama-3.3-70b", Source: "/m", Aliases: []string{"llama", "llama3"},
			Profiles: []catalog.Profile{{Name: "p", GPUClass: "h100-80g", TP: 1}}},
		{Name: "qwen2.5-32b", Source: "/m", Aliases: []string{"qwen"},
			Profiles: []catalog.Profile{{Name: "p", GPUClass: "h100-80g", TP: 1}}},
	}
	if err := s.Validate(); err != nil {
		t.Errorf("valid aliases rejected: %v", err)
	}
}

func TestAnEmptyConfigurationIsAControlPlane(t *testing.T) {
	// A new cluster has no models and no endpoints. Refusing it as having
	// nothing to serve left a systemd unit restarting every two seconds and
	// nothing listening on 8080 — on the first start anyone ever made.
	var s Server
	if !s.ControlPlaneMode() {
		t.Fatal("a configuration with no endpoints and no models should run a control plane")
	}
}

func TestStaticEndpointsAloneAreRouterOnly(t *testing.T) {
	var s Server
	s.Endpoints = []Endpoint{{ID: "e", URL: "http://127.0.0.1:1"}}
	s.Models = []catalog.Model{{Name: "m"}}
	if s.ControlPlaneMode() {
		t.Error("static endpoints and bare model names are the router-only mode")
	}
	s.Control.Enabled = true
	if !s.ControlPlaneMode() {
		t.Error("control.enabled should run the control plane alongside static endpoints")
	}
}

func TestAModelWithProfilesStillMakesAControlPlane(t *testing.T) {
	// The inference stays, so no existing configuration has to add a flag.
	var s Server
	s.Models = []catalog.Model{{
		Name:     "m",
		Profiles: []catalog.Profile{{Name: "p", Engine: "llamacpp"}},
	}}
	if !s.ControlPlaneMode() {
		t.Error("a declared model with profiles is still a control plane")
	}
}

func TestEnginesDefaultToTheCheckedVersions(t *testing.T) {
	var s Server
	if got := s.WantedEngines()["llamacpp"]; got != DefaultEngines["llamacpp"] {
		t.Errorf("unset config wants llamacpp %q", got)
	}
	s.Engines = map[string]string{"llamacpp": "b11000", "vllm": "0.29.0"}
	got := s.WantedEngines()
	if got["llamacpp"] != "b11000" || got["vllm"] != "0.29.0" {
		t.Errorf("configured versions not taken: %v", got)
	}
	// Empty leaves an engine to be installed by hand.
	s.Engines = map[string]string{"llamacpp": ""}
	if _, ok := s.WantedEngines()["llamacpp"]; ok {
		t.Error("an emptied engine is still wanted")
	}
}