Api/middleware/instance.go

package middleware

import (
	"context"
	"fmt"
	"github.com/labstack/echo/v4"
	"net/http"
)

func InstanceId() echo.MiddlewareFunc {
	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(c echo.Context) error {
			s := c.Request().Header.Get("X-Instance-ID")
			if s == "" {
				return echo.NewHTTPError(http.StatusForbidden, "missing or malformed instance id")
			}

			value := context.WithValue(c.Request().Context(), keyInstanceId, s)
			c.SetRequest(c.Request().WithContext(value))
			return next(c)
		}
	}
}

func GetInstanceId(ctx context.Context) (*string, error) {
	id, ok := ctx.Value(keyInstanceId).(string)
	if !ok {
		return nil, fmt.Errorf("missing or malformed instance id")
	}

	return &id, nil
}