Implemented a web server to browse a repository (snapshots, files)

The code is pretty bad and unorganized, I am very new at Go.

But it works!
This commit is contained in:
Alex Duchesne 2024-04-02 17:55:28 -04:00 committed by Alexander Neumann
parent faffd15d13
commit 3541a3a1bf
2 changed files with 281 additions and 0 deletions

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Enhancement: Implement web server to browse snapshots
Currently the canonical way of browsing a repository's snapshots to view
or restore files is `mount`. Unfortunately `mount` depends on fuse which
is not available on all operating systems.
The new `restic serve` command presents a web interface to browse a
repository's snapshots. It allows to view and download files individually
or as a group (as a tar archive) from snapshots.
https://github.com/restic/restic/pull/4276
https://github.com/restic/restic/issues/60

268
cmd/restic/cmd_serve.go Normal file
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package main
import (
"context"
"html/template"
"net/http"
"sort"
"strings"
"time"
"github.com/spf13/cobra"
"github.com/restic/restic/internal/dump"
"github.com/restic/restic/internal/errors"
"github.com/restic/restic/internal/fs"
"github.com/restic/restic/internal/restic"
"github.com/restic/restic/internal/walker"
)
var cmdServe = &cobra.Command{
Use: "serve",
Short: "runs a web server to browse a repository",
Long: `
The serve command runs a web server to browse a repository.
`,
DisableAutoGenTag: true,
RunE: func(cmd *cobra.Command, args []string) error {
return runWebServer(cmd.Context(), serveOptions, globalOptions, args)
},
}
type ServeOptions struct {
Listen string
}
var serveOptions ServeOptions
func init() {
cmdRoot.AddCommand(cmdServe)
cmdFlags := cmdServe.Flags()
cmdFlags.StringVarP(&serveOptions.Listen, "listen", "l", "localhost:3080", "set the listen host name and `address`")
}
type fileNode struct {
Path string
Node *restic.Node
}
func listNodes(ctx context.Context, repo restic.Repository, tree restic.ID, path string) ([]fileNode, error) {
var files []fileNode
err := walker.Walk(ctx, repo, tree, nil, func(_ restic.ID, nodepath string, node *restic.Node, err error) (bool, error) {
if err != nil || node == nil {
return false, err
}
if fs.HasPathPrefix(path, nodepath) {
files = append(files, fileNode{nodepath, node})
}
if node.Type == "dir" && !fs.HasPathPrefix(nodepath, path) {
return false, walker.ErrSkipNode
}
return false, nil
})
return files, err
}
func runWebServer(ctx context.Context, opts ServeOptions, gopts GlobalOptions, args []string) error {
if len(args) > 0 {
return errors.Fatal("this command does not accept additional arguments")
}
repo, err := OpenRepository(ctx, gopts)
if err != nil {
return err
}
if !gopts.NoLock {
var lock *restic.Lock
lock, ctx, err = lockRepo(ctx, repo)
defer unlockRepo(lock)
if err != nil {
return err
}
}
err = repo.LoadIndex(ctx)
if err != nil {
return err
}
funcMap := template.FuncMap{
"FormatTime": func(time time.Time) string { return time.Format(TimeFormat) },
}
indexPage := template.Must(template.New("index").Funcs(funcMap).Parse(indexPageTpl))
treePage := template.Must(template.New("tree").Funcs(funcMap).Parse(treePageTpl))
http.HandleFunc("/tree/", func(w http.ResponseWriter, r *http.Request) {
snapshotID, curPath, _ := strings.Cut(r.URL.Path[6:], "/")
curPath = "/" + strings.Trim(curPath, "/")
_ = r.ParseForm()
sn, err := restic.FindSnapshot(ctx, repo.Backend(), repo, snapshotID)
if err != nil {
http.Error(w, "Snapshot not found: "+err.Error(), http.StatusNotFound)
return
}
files, err := listNodes(ctx, repo, *sn.Tree, curPath)
if err != nil || len(files) == 0 {
http.Error(w, "Path not found in snapshot", http.StatusNotFound)
return
}
if r.Form.Get("action") == "dump" {
var tree restic.Tree
for _, file := range files {
for _, name := range r.Form["name"] {
if name == file.Node.Name {
tree.Nodes = append(tree.Nodes, file.Node)
}
}
}
if len(tree.Nodes) > 0 {
filename := strings.ReplaceAll(strings.Trim(snapshotID+curPath, "/"), "/", "_") + ".tar.gz"
w.Header().Set("Content-Disposition", "attachment; filename=\""+filename+"\"")
// For now it's hardcoded to tar because it's the only format that supports all node types correctly
if err := dump.New("tar", repo, w).DumpTree(ctx, &tree, "/"); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
return
}
}
if len(files) == 1 && files[0].Node.Type == "file" {
if err := dump.New("zip", repo, w).WriteNode(ctx, files[0].Node); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
return
}
var rows []treePageRow
for _, item := range files {
if item.Path != curPath {
rows = append(rows, treePageRow{"/tree/" + snapshotID + item.Path, item.Node.Name, item.Node.Type, item.Node.Size, item.Node.ModTime})
}
}
sort.SliceStable(rows, func(i, j int) bool {
return strings.ToLower(rows[i].Name) < strings.ToLower(rows[j].Name)
})
sort.SliceStable(rows, func(i, j int) bool {
return rows[i].Type == "dir" && rows[j].Type != "dir"
})
parent := "/tree/" + snapshotID + curPath + "/.."
if curPath == "/" {
parent = "/"
}
if err := treePage.Execute(w, treePageData{snapshotID + ": " + curPath, parent, rows}); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
})
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
var rows []indexPageRow
for sn := range FindFilteredSnapshots(ctx, repo.Backend(), repo, &restic.SnapshotFilter{}, nil) {
rows = append(rows, indexPageRow{"/tree/" + sn.ID().Str() + "/", sn.ID().Str(), sn.Time, sn.Hostname, sn.Tags, sn.Paths})
}
sort.Slice(rows, func(i, j int) bool {
return rows[i].Time.After(rows[j].Time)
})
if err := indexPage.Execute(w, indexPageData{"Snapshots", rows}); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
})
http.HandleFunc("/style.css", func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Cache-Control", "max-age=300")
_, _ = w.Write([]byte(stylesheetTxt))
})
Printf("Now serving the repository at http://%s\n", opts.Listen)
Printf("When finished, quit with Ctrl-c here.\n")
return http.ListenAndServe(opts.Listen, nil)
}
type indexPageRow struct {
Link string
ID string
Time time.Time
Host string
Tags []string
Paths []string
}
type indexPageData struct {
Title string
Rows []indexPageRow
}
type treePageRow struct {
Link string
Name string
Type string
Size uint64
Time time.Time
}
type treePageData struct {
Title string
Parent string
Rows []treePageRow
}
const indexPageTpl = `<html>
<head>
<link rel="stylesheet" href="/style.css">
<title>{{.Title}} :: restic</title>
</head>
<body>
<h1>{{.Title}}</h1>
<table>
<thead><tr><th>ID</th><th>Time</th><th>Host</th><th>Tags</th><th>Paths</th></tr></thead>
<tbody>
{{range .Rows}}
<tr><td><a href="{{.Link}}">{{.ID}}</a></td><td>{{.Time | FormatTime}}</td><td>{{.Host}}</td><td>{{.Tags}}</td><td>{{.Paths}}</td></tr>
{{end}}
</tbody>
</table>
</body>
</html>`
const treePageTpl = `<html>
<head>
<link rel="stylesheet" href="/style.css">
<title>{{.Title}} :: restic</title>
</head>
<body>
<h1>{{.Title}}</h1>
<form method="post">
<table>
<thead><tr><th><input type="checkbox" onclick="document.querySelectorAll('.content input[type=checkbox]').forEach(cb => cb.checked = this.checked)"></th><th>Name</th><th>Type</th><th>Size</th><th>Date modified</th></tr></thead>
<tbody class="content">
{{if .Parent}}<tr><td></td><td><a href="{{.Parent}}">..</a></td><td>parent</td><td></td><td></tr>{{end}}
{{range .Rows}}
<tr><td><input type="checkbox" name="name" value="{{.Name}}"></td><td><a class="{{.Type}}" href="{{.Link}}">{{.Name}}</a></td><td>{{.Type}}</td><td>{{.Size}}</td><td>{{.Time | FormatTime}}</td></td></tr>
{{end}}
</tbody>
<tbody class="actions">
<tr><td colspan="100"><button name="action" value="dump" type="submit">Download selection</button></td></tr>
</tbody>
</table>
</form>
</body>
</html>`
const stylesheetTxt = `
h1,h2,h3 {text-align:center; margin: 0.5em;}
table {margin: 0 auto;border-collapse: collapse; }
thead th {text-align: left; font-weight: bold;}
tbody.content tr:hover {background: #eee;}
tbody.content a.file:before {content: '\1F4C4'}
tbody.content a.dir:before {content: '\1F4C1'}
tbody.actions td {padding:.5em;}
table, td, tr, th { border: 1px solid black; padding: .1em .5em;}
`