cmd/tsconnect: initial scaffolding for Tailscale Connect browser client

Runs a Tailscale client in the browser (via a WebAssembly build of the wasm package) and allows SSH access to machines. The wasm package exports a newIPN function, which returns a simple JS object with methods like start(), login(), logout() and ssh(). The golang.org/x/crypto/ssh package is used for the SSH client. Terminal emulation and QR code renedring is done via NPM packages (xterm and qrcode respectively), thus we also need a JS toolchain that can install and bundle them. Yarn is used for installation, and esbuild handles loading them and bundling for production serving. Updates #3157 Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2022-06-07 14:24:22 -07:00
parent 2a22ea3e83
commit 6f5096fa61
19 changed files with 1509 additions and 0 deletions
@@ -0,0 +1,152 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io"
+	"io/fs"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/andybalholm/brotli"
+	esbuild "github.com/evanw/esbuild/pkg/api"
+	"golang.org/x/sync/errgroup"
+)
+
+func runBuild() {
+	buildOptions, err := commonSetup(prodMode)
+	if err != nil {
+		log.Fatalf("Cannot setup: %v", err)
+	}
+
+	if err := cleanDist(); err != nil {
+		log.Fatalf("Cannot clean dist/: %v", err)
+	}
+
+	buildOptions.Write = true
+	buildOptions.MinifyWhitespace = true
+	buildOptions.MinifyIdentifiers = true
+	buildOptions.MinifySyntax = true
+
+	buildOptions.EntryNames = "[dir]/[name]-[hash]"
+	buildOptions.AssetNames = "[name]-[hash]"
+	buildOptions.Metafile = true
+
+	log.Printf("Running esbuild...\n")
+	result := esbuild.Build(*buildOptions)
+	if len(result.Errors) > 0 {
+		log.Printf("ESBuild Error:\n")
+		for _, e := range result.Errors {
+			log.Printf("%v", e)
+		}
+		log.Fatal("Build failed")
+	}
+	if len(result.Warnings) > 0 {
+		log.Printf("ESBuild Warnings:\n")
+		for _, w := range result.Warnings {
+			log.Printf("%v", w)
+		}
+	}
+
+	// Preserve build metadata so we can extract hashed file names for serving.
+	if err := ioutil.WriteFile("./dist/esbuild-metadata.json", []byte(result.Metafile), 0666); err != nil {
+		log.Fatalf("Cannot write metadata: %v", err)
+	}
+
+	if er := precompressDist(); err != nil {
+		log.Fatalf("Cannot precompress resources: %v", er)
+	}
+}
+
+// cleanDist removes files from the dist build directory, except the placeholder
+// one that we keep to make sure Git still creates the directory.
+func cleanDist() error {
+	log.Printf("Cleaning dist/...\n")
+	files, err := os.ReadDir("dist")
+	if err != nil {
+		return err
+	}
+
+	for _, file := range files {
+		if file.Name() != "placeholder" {
+			if err := os.Remove(filepath.Join("dist", file.Name())); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func precompressDist() error {
+	log.Printf("Pre-compressing files in dist/...\n")
+	var eg errgroup.Group
+	err := fs.WalkDir(os.DirFS("./"), "dist", func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() {
+			return nil
+		}
+		if !compressibleExtensions[filepath.Ext(path)] {
+			return nil
+		}
+		log.Printf("Pre-compressing %v\n", path)
+
+		eg.Go(func() error {
+			return precompress(path)
+		})
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+	return eg.Wait()
+}
+
+var compressibleExtensions = map[string]bool{
+	".js":   true,
+	".css":  true,
+	".wasm": true,
+}
+
+func precompress(path string) error {
+	contents, err := os.ReadFile(path)
+	if err != nil {
+		return err
+	}
+	fi, err := os.Lstat(path)
+	if err != nil {
+		return err
+	}
+
+	err = writeCompressed(contents, func(w io.Writer) (io.WriteCloser, error) {
+		return gzip.NewWriterLevel(w, gzip.BestCompression)
+	}, path+".gz", fi.Mode())
+	if err != nil {
+		return err
+	}
+	return writeCompressed(contents, func(w io.Writer) (io.WriteCloser, error) {
+		return brotli.NewWriterLevel(w, brotli.BestCompression), nil
+	}, path+".br", fi.Mode())
+}
+
+func writeCompressed(contents []byte, compressedWriterCreator func(io.Writer) (io.WriteCloser, error), outputPath string, outputMode fs.FileMode) error {
+	var buf bytes.Buffer
+	compressedWriter, err := compressedWriterCreator(&buf)
+	if err != nil {
+		return err
+	}
+	if _, err := compressedWriter.Write(contents); err != nil {
+		return err
+	}
+	if err := compressedWriter.Close(); err != nil {
+		return err
+	}
+	return os.WriteFile(outputPath, buf.Bytes(), outputMode)
+}