many fixes

cmd/tailpaste:
- better handle the error cases from web

cmd/web:
- Implement list of pastes
- Add contextual navbar for paste list and meta help
- Add error page rendering
- Add paginated paste listing
- Add created_at column
- Make paster information less janky on per-paste views

Signed-off-by: Xe Iaso <xe@tailscale.com>

cmd/tailpaste/main.go

@@ -61,7 +61,7 @@ func main() {
 	q.Set("filename", filepath.Base(*fname))
 	q.Set("content", string(data))
 
-	req, err := http.NewRequest(http.MethodPost, u.String(), strings.NewReader(q.Encode))
+	req, err := http.NewRequest(http.MethodPost, u.String(), strings.NewReader(q.Encode()))
 	if err != nil {
 		log.Fatalf("can't make HTTP request: %v", err)
 	}

cmd/web/main.go

@@ -12,8 +12,10 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"text/template"
+	"time"
 
 	"github.com/google/uuid"
 	"github.com/tailscale/sqlite"
@@ -68,8 +70,7 @@ func (s *Server) TailnetIndex(w http.ResponseWriter, r *http.Request) {
 
 	ui, err := upsertUserInfo(r.Context(), s.db, s.lc, r.RemoteAddr)
 	if err != nil {
-		log.Printf("%s: error fetching user info: %v", r.RemoteAddr, err)
+			s.ShowError(w, r, err, http.StatusInternalServerError)
-		http.Error(w, "can't fetch user info", http.StatusBadRequest)
 		return
 	}
 
@@ -147,6 +148,7 @@ func (s *Server) TailnetSubmitPaste(w http.ResponseWriter, r *http.Request) {
 	q := `
 INSERT INTO pastes
     ( id
+    , created_at
     , user_id
     , filename
     , data
@@ -156,19 +158,20 @@ VALUES
     , ?2
     , ?3
     , ?4
+    , ?5
     )`
 
 	_, err = s.db.ExecContext(
 		r.Context(),
 		q,
 		id,
+		time.Now(),
 		userInfo.UserProfile.ID,
 		fname,
 		data,
 	)
 	if err != nil {
-		log.Printf("%s: %v", r.RemoteAddr, err)
+			s.ShowError(w, r, err, http.StatusInternalServerError)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 
@@ -184,6 +187,126 @@ VALUES
 
 }
 
+func (s *Server) TailnetPasteIndex(w http.ResponseWriter, r *http.Request) {
+	userInfo, err := upsertUserInfo(r.Context(), s.db, s.lc, r.RemoteAddr)
+	if err != nil {
+			s.ShowError(w, r, err, http.StatusInternalServerError)
+		return
+	}
+
+	_ = userInfo
+
+	type JoinedPasteInfo struct {
+		ID                string `json:"id"`
+		Filename          string `json:"fname"`
+		CreatedAt         string `json:"created_at"`
+		PasterDisplayName string `json:"created_by"`
+	}
+
+	q := `
+SELECT p.id
+     , p.filename
+     , p.created_at
+     , u.display_name
+FROM pastes p
+INNER JOIN users u
+  ON p.user_id = u.id
+LIMIT 25
+OFFSET ?1
+`
+
+	uq := r.URL.Query()
+	page := uq.Get("page")
+	if page == "" {
+		page = "0"
+	}
+
+	pageNum, err := strconv.Atoi(page)
+	if err != nil {
+		log.Printf("%s: invalid ?page: %s: %v", r.RemoteAddr, page, err)
+		pageNum = 0
+	}
+
+	rows, err := s.db.Query(q, clampToZero(pageNum))
+	if err != nil {
+			s.ShowError(w, r, err, http.StatusInternalServerError)
+		return
+	}
+
+	jpis := make([]JoinedPasteInfo, 0, 25)
+
+	defer rows.Close()
+	for rows.Next() {
+		jpi := JoinedPasteInfo{}
+
+		err := rows.Scan(&jpi.ID, &jpi.Filename, &jpi.CreatedAt, &jpi.PasterDisplayName)
+		if err != nil {
+			s.ShowError(w, r, err, http.StatusInternalServerError)
+			return
+		}
+
+		jpis = append(jpis, jpi)
+	}
+
+	if len(jpis) == 0 {
+
+	}
+
+	var prev, next *int
+
+	if pageNum != 0 {
+		i := pageNum - 1
+		prev = &i
+	}
+	if len(jpis) == 25 {
+		i := pageNum + 1
+		next = &i
+	}
+
+	err = s.tmpls.ExecuteTemplate(w, "listpaste.tmpl", struct {
+		UserInfo *tailcfg.UserProfile
+		Title    string
+		Pastes   []JoinedPasteInfo
+		Prev     *int
+		Next     *int
+		Page     int
+	}{
+		UserInfo: userInfo.UserProfile,
+		Title:    "Pastes",
+		Pastes:   jpis,
+		Prev:     prev,
+		Next:     next,
+		Page:     pageNum,
+	})
+	if err != nil {
+		log.Printf("%s: %v", r.RemoteAddr, err)
+	}
+}
+
+func (s *Server) ShowError(w http.ResponseWriter, r *http.Request, err error, code int) {
+	w.Header().Set("Content-Type", "text/html")
+	w.WriteHeader(code)
+
+	log.Printf("%s: %v", r.RemoteAddr, err)
+
+	if err := s.tmpls.ExecuteTemplate(w, "error.tmpl", struct {
+		Title, Error string
+		UserInfo     any
+	}{
+		Title: "Oh noes!",
+		Error: err.Error(),
+	}); err != nil {
+		log.Printf("%s: %v", r.RemoteAddr, err)
+	}
+}
+
+func clampToZero(i int) int {
+	if i <= 0 {
+		return 0
+	}
+	return i
+}
+
 func (s *Server) ShowPost(w http.ResponseWriter, r *http.Request) {
 	ui, _ := upsertUserInfo(r.Context(), s.db, s.lc, r.RemoteAddr)
 	var up *tailcfg.UserProfile
@@ -208,6 +331,7 @@ func (s *Server) ShowPost(w http.ResponseWriter, r *http.Request) {
 
 	q := `
 SELECT p.filename
+     , p.created_at
      , p.data
      , u.id
      , u.login_name
@@ -220,11 +344,11 @@ WHERE p.id = ?1`
 
 	row := s.db.QueryRowContext(r.Context(), q, id)
 	var fname, data, userID, userLoginName, userDisplayName, userProfilePicURL string
+	var createdAt string
 
-	err := row.Scan(&fname, &data, &userID, &userLoginName, &userDisplayName, &userProfilePicURL)
+	err := row.Scan(&fname, &createdAt, &data, &userID, &userLoginName, &userDisplayName, &userProfilePicURL)
 	if err != nil {
-		log.Printf("%s: looking up %s: %v", r.RemoteAddr, id, err)
+		s.ShowError(w, r, fmt.Errorf("can't find paste %s: %w", id, err), http.StatusInternalServerError)
-		http.Error(w, fmt.Sprintf("can't find paste %s: %v", id, err), http.StatusInternalServerError)
 		return
 	}
 
@@ -252,6 +376,7 @@ WHERE p.id = ?1`
 	err = s.tmpls.ExecuteTemplate(w, "showpaste.tmpl", struct {
 		UserInfo            *tailcfg.UserProfile
 		Title               string
+		CreatedAt           string
 		PasterDisplayName   string
 		PasterProfilePicURL string
 		ID                  string
@@ -259,6 +384,7 @@ WHERE p.id = ?1`
 	}{
 		UserInfo:            up,
 		Title:               fname,
+		CreatedAt:           createdAt,
 		PasterDisplayName:   userDisplayName,
 		PasterProfilePicURL: userProfilePicURL,
 		ID:                  id,
@@ -309,6 +435,7 @@ func main() {
 	tailnetMux := http.NewServeMux()
 	tailnetMux.Handle("/static/", http.FileServer(http.FS(staticFiles)))
 	tailnetMux.HandleFunc("/paste/", srv.ShowPost)
+	tailnetMux.HandleFunc("/paste/list", srv.TailnetPasteIndex)
 	tailnetMux.HandleFunc("/api/post", srv.TailnetSubmitPaste)
 	tailnetMux.HandleFunc("/", srv.TailnetIndex)
 

cmd/web/schema.sql

@@ -4,6 +4,7 @@ PRAGMA journal_mode=WAL;
 -- Paste data
 CREATE TABLE IF NOT EXISTS pastes
   ( id TEXT PRIMARY KEY NOT NULL
+  , created_at TEXT NOT NULL -- RFC 3339 timestamp
   , user_id TEXT NOT NULL
   , filename TEXT NOT NULL
   , data TEXT NOT NULL

cmd/web/tmpl/base.tmpl

@@ -9,7 +9,7 @@
     <body id="top">
         <main>
             <nav>
-                <a href="/">Paste</a>
+                <a href="/">Paste</a>{{if .UserInfo}} - <a href="/paste/list">List</a> - <a href="/help">Help</a>{{end}}
                 {{if .UserInfo}}<div class="right">{{.UserInfo.DisplayName}} <img style="width:32px;height:32px" src="{{.UserInfo.ProfilePicURL}}" /></div>{{end}}
             </nav>
 

cmd/web/tmpl/create.tmpl

@@ -6,4 +6,8 @@
   <input type="text" id="filename" name="filename" value="filename.txt" />
   <input type="submit" value="Submit" />
 </form>
+
+<br />
+<br />
+<a href="/paste/list">See all pastes</a>
 {{template "footer" .}}

cmd/web/tmpl/error.tmpl

@@ -0,0 +1,9 @@
+{{template "header" .}}
+Oh noes! There was an error when trying to do this thing:
+
+<code><pre>
+{{.Error}}
+</code></pre>
+
+This is almost certainly not what was anticipated, and if you think you are seeing this in error, please contact your administrator or Tailscale support for help with the program itself.
+{{template "footer" .}}

cmd/web/tmpl/listpaste.tmpl

@@ -0,0 +1,11 @@
+{{template "header" .}}
+
+<ul>
+    {{range .Pastes}}
+    <li><a href="/paste/{{.ID}}">{{.Filename}}</a> - {{.CreatedAt}} - {{.PasterDisplayName}}</li>
+    {{end}}
+</ul>
+
+<p>{{if .Prev}}<a href="/paste/list?page={{.Prev}}">Prev</a> - {{end}} Page {{.Page}} {{if .Next}} - <a href="/paste/list?page={{.Next}}">Next</a>{{end}}</p>
+
+{{template "footer" .}}

cmd/web/tmpl/notfound.tmpl

@@ -1,3 +1,3 @@
 {{template "header" .}}
-<p>The URL you requested could not be found. Please check your URL and hang up to try your call again.
+<p>The URL you requested could not be found. Please check your URL and hang up to try your call again.</p>
 {{template "footer" .}}

cmd/web/tmpl/showpaste.tmpl

@@ -1,6 +1,8 @@
 {{template "header" .}}
 
-<div class="right">{{.PasterDisplayName}} <img style="width:32px;height:32px" src="{{.PasterProfilePicURL}}" /></div>
+<div class="right"><img style="width:32px;height:32px" src="{{.PasterProfilePicURL}}" /></div>
+
+<p>Created at {{.CreatedAt}} by {{.PasterDisplayName}}</p>
 
 <pre><code>
 {{.Data}}