From bfeddd25d108b40bc63bff6f53a64a434ed80102 Mon Sep 17 00:00:00 2001
From: Jamie Holdstock <jholdstock@decred.org>
Date: Fri, 12 Jun 2020 14:32:29 +0100
Subject: [PATCH] Download db backup from admin page.

---
 database/database.go        | 16 ++++++++++++++++
 webapi/admin.go             | 14 ++++++++++++--
 webapi/templates/admin.html |  7 +++++--
 webapi/templates/login.html |  2 +-
 webapi/webapi.go            |  1 +
 5 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/database/database.go b/database/database.go
index 0f4c4ba..146a09c 100644
--- a/database/database.go
+++ b/database/database.go
@@ -6,7 +6,9 @@ import (
 	"crypto/rand"
 	"encoding/binary"
 	"fmt"
+	"net/http"
 	"os"
+	"strconv"
 	"sync"
 	"time"
 
@@ -247,3 +249,17 @@ func (vdb *VspDatabase) GetCookieSecret() ([]byte, error) {
 
 	return cookieSecret, err
 }
+
+// BackupDB streams a backup of the database over an http response writer.
+func (vdb *VspDatabase) BackupDB(w http.ResponseWriter) error {
+	w.Header().Set("Content-Type", "application/octet-stream")
+	w.Header().Set("Content-Disposition", `attachment; filename="vspd.db"`)
+
+	err := vdb.db.View(func(tx *bolt.Tx) error {
+		w.Header().Set("Content-Length", strconv.Itoa(int(tx.Size())))
+		_, err := tx.WriteTo(w)
+		return err
+	})
+
+	return err
+}
diff --git a/webapi/admin.go b/webapi/admin.go
index 7a99bdf..32d7b4d 100644
--- a/webapi/admin.go
+++ b/webapi/admin.go
@@ -14,8 +14,8 @@ func adminPage(c *gin.Context) {
 	})
 }
 
-// ticketSearch is the handler for "POST /admin/ticket". The "hash" param will
-// be used to retrieve a ticket from the database.
+// ticketSearch is the handler for "POST /admin/ticket". The hash param will be
+// used to retrieve a ticket from the database.
 func ticketSearch(c *gin.Context) {
 	hash := c.PostForm("hash")
 
@@ -59,6 +59,16 @@ func adminLogout(c *gin.Context) {
 	setAdminStatus(nil, c)
 }
 
+// downloadDatabaseBackup is the handler for "GET /backup". A binary
+// representation of the whole database is generated and returned to the client.
+func downloadDatabaseBackup(c *gin.Context) {
+	err := db.BackupDB(c.Writer)
+	if err != nil {
+		log.Errorf("Error backing up database: %v", err)
+		c.String(http.StatusInternalServerError, "Error backing up database")
+	}
+}
+
 // setAdminStatus stores the authentication status of the current session and
 // redirects the client to GET /admin.
 func setAdminStatus(admin interface{}, c *gin.Context) {
diff --git a/webapi/templates/admin.html b/webapi/templates/admin.html
index 6c126e1..bfc10f1 100644
--- a/webapi/templates/admin.html
+++ b/webapi/templates/admin.html
@@ -4,13 +4,16 @@
 
 <section>
     <h3>Admin</h3>
+
+    <a class="btn btn-primary" href="/admin/backup" download>Backup Database</a>
+
     <form class="my-2" action="/admin/logout" method="post">
-        <button type="submit">Logout</button>
+        <button class="btn btn-primary" type="submit">Logout</button>
     </form>
 
     <form class="my-2" action="/admin/ticket" method="post">
         <input type="text" name="hash" size="64" minlength="64" maxlength="64" required placeholder="Ticket hash">
-        <button type="submit">Search</button>
+        <button class="btn btn-primary" type="submit">Search</button>
     </form>
 
     {{ with .SearchResult }}
diff --git a/webapi/templates/login.html b/webapi/templates/login.html
index f9263ab..b86f080 100644
--- a/webapi/templates/login.html
+++ b/webapi/templates/login.html
@@ -4,7 +4,7 @@
     <h3>Login</h3>
     <form action="/admin" method="post">
         <input type="password" name="password" required placeholder="Enter password">
-        <button type="submit">Login</button>
+        <button class="btn btn-primary" type="submit">Login</button>
     </form>
 
     {{ if .IncorrectPassword }}
diff --git a/webapi/webapi.go b/webapi/webapi.go
index a352b29..9aef5ee 100644
--- a/webapi/webapi.go
+++ b/webapi/webapi.go
@@ -207,6 +207,7 @@ func router(debugMode bool, cookieSecret []byte, dcrd rpc.DcrdConnect, wallets r
 	)
 	admin.GET("", adminPage)
 	admin.POST("/ticket", ticketSearch)
+	admin.GET("/backup", downloadDatabaseBackup)
 	admin.POST("/logout", adminLogout)
 
 	// These API routes access dcrd and the voting wallets, and they need