refactor: move remaining api packages to core (#1731)

* core 1

* api/openai/files fix

* core 2 - core/config

* move over core api.go and tests to the start of core/http

* move over localai specific endpoints to core/http, begin the service/endpoint split there

* refactor big chunk on the plane

* refactor chunk 2 on plane, next step: port and modify changes to request.go

* easy fixes for request.go, major changes not done yet

* lintfix

* json tag lintfix?

* gitignore and .keep files

* strange fix attempt: rename the config dir?

core/http/endpoints/localai/metrics.go

@@ -0,0 +1,43 @@
+package localai
+
+import (
+	"time"
+
+	"github.com/go-skynet/LocalAI/core/services"
+	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/middleware/adaptor"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+func LocalAIMetricsEndpoint() fiber.Handler {
+
+	return adaptor.HTTPHandler(promhttp.Handler())
+}
+
+type apiMiddlewareConfig struct {
+	Filter         func(c *fiber.Ctx) bool
+	metricsService *services.LocalAIMetricsService
+}
+
+func LocalAIMetricsAPIMiddleware(metrics *services.LocalAIMetricsService) fiber.Handler {
+	cfg := apiMiddlewareConfig{
+		metricsService: metrics,
+		Filter: func(c *fiber.Ctx) bool {
+			return c.Path() == "/metrics"
+		},
+	}
+
+	return func(c *fiber.Ctx) error {
+		if cfg.Filter != nil && cfg.Filter(c) {
+			return c.Next()
+		}
+		path := c.Path()
+		method := c.Method()
+
+		start := time.Now()
+		err := c.Next()
+		elapsed := float64(time.Since(start)) / float64(time.Second)
+		cfg.metricsService.ObserveAPICall(method, path, elapsed)
+		return err
+	}
+}