depot/web/fup/cmd/serve.go
2021-03-26 21:44:13 +00:00

121 lines
4.8 KiB
Go

// SPDX-FileCopyrightText: 2021 Luke Granger-Brown <depot@lukegb.com>
//
// SPDX-License-Identifier: Apache-2.0
package cmd
import (
"context"
"fmt"
"log"
"net/http"
"os/exec"
"strings"
"github.com/coreos/go-systemd/v22/activation"
"github.com/google/safehtml"
"github.com/spf13/cobra"
"github.com/spf13/viper"
"hg.lukegb.com/lukegb/depot/web/fup/fuphttp"
"hg.lukegb.com/lukegb/depot/web/fup/fupstatic"
"hg.lukegb.com/lukegb/depot/web/fup/minicheddar"
)
func init() {
rootCmd.AddCommand(serveCmd)
serveCmd.Flags().String("root", "http://localhost:8191/", "Application root address.")
viper.BindPFlag("serve.app-root", serveCmd.Flags().Lookup("root"))
viper.SetDefault("serve.app-root", "http://localhost:8191/")
serveCmd.Flags().String("static-root", "/static/", "Root address from which static assets should be referenced.")
viper.BindPFlag("serve.static-root", serveCmd.Flags().Lookup("static-root"))
viper.SetDefault("serve.static-root", "/static/")
serveCmd.Flags().StringP("listen", "l", ":8191", "Bind address for HTTP server.")
viper.BindPFlag("serve.listen", serveCmd.Flags().Lookup("listen"))
viper.SetDefault("serve.listen", ":8191")
serveCmd.Flags().Bool("direct-only", false, "If set, all file serving will be proxied, even if the backend supports signed URLs.")
viper.BindPFlag("serve.direct-only", serveCmd.Flags().Lookup("direct-only"))
viper.SetDefault("serve.direct-only", false)
serveCmd.Flags().String("cheddar-path", "cheddar", "Path to 'cheddar' binary to use for syntax highlighting. If it cannot be found, syntax highlighting and markdown rendering will be disabled.")
viper.BindPFlag("serve.cheddar.path", serveCmd.Flags().Lookup("cheddar-path"))
viper.SetDefault("serve.cheddar.path", "cheddar")
serveCmd.Flags().String("cheddar-address", "", "If non-empty, will be used instead of attempting to spawn a copy of cheddar.")
viper.BindPFlag("serve.cheddar.address", serveCmd.Flags().Lookup("cheddar-address"))
serveCmd.Flags().String("auth-token", "", "If non-empty, this auth token will be required as the Basic Auth password.")
viper.BindPFlag("serve.auth.token", serveCmd.Flags().Lookup("auth-token"))
serveCmd.Flags().String("auth-realm", "fup", "Will be used as the realm for Basic Auth.")
viper.BindPFlag("serve.auth.realm", serveCmd.Flags().Lookup("auth-realm"))
viper.SetDefault("serve.auth.realm", "fup")
}
var (
serveCmd = &cobra.Command{
Use: "serve",
Short: "Serve HTTP",
RunE: func(cmd *cobra.Command, args []string) error {
if !strings.HasSuffix(viper.GetString("serve.app-root"), "/") {
return fmt.Errorf("--root flag (serve.app-root) should end in / (value is %q)", viper.GetString("serve.app-root"))
}
if !strings.HasSuffix(viper.GetString("serve.static-root"), "/") {
return fmt.Errorf("--static-root flag (serve.static-root) should end in / (value is %q)", viper.GetString("serve.static-root"))
}
ctx := context.Background()
highlighter, err := serveCheddar(ctx)
if err != nil {
return fmt.Errorf("spawning cheddar syntax highlighter: %v", err)
}
cfg := &fuphttp.Config{
Templates: fupstatic.Templates,
Static: fupstatic.Static,
StaticRoot: safehtml.TrustedResourceURLFromFlag(cmd.Flag("static-root").Value),
AppRoot: viper.GetString("serve.app-root"),
StorageURL: bucketURL(),
RedirectToBlobstore: !viper.GetBool("serve.direct-only"),
AuthMiddleware: fuphttp.TokenAuthMiddleware(viper.GetString("serve.auth.token"), viper.GetString("serve.auth.realm")),
}
if highlighter != nil {
cfg.Highlighter = highlighter
}
a, err := fuphttp.New(ctx, cfg)
if err != nil {
return fmt.Errorf("constructing application: %w", err)
}
http.Handle("/", a.Handler())
http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.FS(fupstatic.Static))))
log.Printf("Serving on %s", viper.GetString("serve.listen"))
if viper.GetString("serve.listen") == "systemd" {
listeners, err := activation.Listeners()
if err != nil {
return fmt.Errorf("getting systemd socket-activated listeners: %v", err)
}
if len(listeners) != 1 {
return fmt.Errorf("unexpected systemd socket activation fds: got %d; want 1", len(listeners))
}
return http.Serve(listeners[0], nil)
}
return http.ListenAndServe(viper.GetString("serve.listen"), nil)
},
}
)
func serveCheddar(ctx context.Context) (*minicheddar.Cheddar, error) {
if serveCheddarAddr := viper.GetString("serve.cheddar.addr"); serveCheddarAddr != "" {
return minicheddar.Remote(serveCheddarAddr), nil
}
cpath, err := exec.LookPath(viper.GetString("serve.cheddar.path"))
if err != nil {
log.Printf("couldn't find cheddar at %q; disabling syntax highlighting", viper.GetString("serve.cheddar.path"))
return nil, nil
}
return minicheddar.Spawn(ctx, cpath)
}