memos/server/frontend/frontend.go

package frontend

import (
	"embed"
	"io/fs"
	"net/http"
	"strings"

	"github.com/labstack/echo/v4"
	"github.com/labstack/echo/v4/middleware"

	"github.com/usememos/memos/internal/util"
)

//go:embed dist
var embeddedFiles embed.FS

//go:embed dist/index.html
var rawIndexHTML string

func Serve(e *echo.Echo) {
	// Use echo static middleware to serve the built dist folder
	// refer: https://github.com/labstack/echo/blob/master/middleware/static.go
	e.Use(middleware.StaticWithConfig(middleware.StaticConfig{
		Skipper:    defaultAPIRequestSkipper,
		HTML5:      true,
		Filesystem: getFileSystem("dist"),
	}))

	assetsGroup := e.Group("assets")
	assetsGroup.Use(middleware.GzipWithConfig(middleware.GzipConfig{
		Skipper: defaultAPIRequestSkipper,
		Level:   5,
	}))
	assetsGroup.Use(func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(c echo.Context) error {
			c.Response().Header().Set(echo.HeaderCacheControl, "max-age=31536000, immutable")
			return next(c)
		}
	})
	assetsGroup.Use(middleware.StaticWithConfig(middleware.StaticConfig{
		Skipper:    defaultAPIRequestSkipper,
		HTML5:      true,
		Filesystem: getFileSystem("dist/assets"),
	}))

	registerRoutes(e)
}

func registerRoutes(e *echo.Echo) {
	e.GET("/m/:memoID", func(c echo.Context) error {
		indexHTML := strings.ReplaceAll(rawIndexHTML, "<!-- memos.metadata -->", "<meta name=\"memos-memo-id\" content=\""+c.Param("memoID")+"\">"+"\n")
		return c.HTML(http.StatusOK, indexHTML)
	})
}

func getFileSystem(path string) http.FileSystem {
	fs, err := fs.Sub(embeddedFiles, path)
	if err != nil {
		panic(err)
	}
	return http.FS(fs)
}

func defaultAPIRequestSkipper(c echo.Context) bool {
	path := c.Request().URL.Path
	return util.HasPrefixes(path, "/api", "/memos.api.v2")
}