From a0bd7d865087b75519403bf9ff0b84de7aa028fa Mon Sep 17 00:00:00 2001
From: Catherine <whitequark@whitequark.org>
Date: Wed, 17 Sep 2025 13:13:58 +0000
Subject: [PATCH] Implement migration from v1 data layout.

---
 src/main.go     | 16 ++++++++
 src/manifest.go |  2 +-
 src/migrate.go  | 97 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/update.go   |  2 +-
 4 files changed, 115 insertions(+), 2 deletions(-)
 create mode 100644 src/migrate.go

diff --git a/src/main.go b/src/main.go
index 36eedb5..d8cb00b 100644
--- a/src/main.go
+++ b/src/main.go
@@ -5,6 +5,7 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"os"
 )
 
 var backend Backend
@@ -26,6 +27,7 @@ func main() {
 	var err error
 
 	configPath := flag.String("config", "config.toml", "path to configuration file")
+	migrateV1Path := flag.String("migrate-v1", "", "path to v1 data directory to upload")
 	flag.Parse()
 
 	if err := ReadConfig(*configPath); err != nil {
@@ -55,6 +57,20 @@ func main() {
 		log.Fatalln("unknown backend:", config.Backend.Type)
 	}
 
+	if *migrateV1Path != "" {
+		root, err := os.OpenRoot(*migrateV1Path)
+		if err != nil {
+			log.Fatalln("migrate v1:", err)
+		}
+
+		err = MigrateFromV1(root)
+		if err != nil {
+			log.Fatalln("migrate v1:", err)
+		}
+
+		log.Println("migrate v1 ok")
+	}
+
 	log.Println("ready")
 
 	if config.Caddy != (ListenConfig{}) {
diff --git a/src/manifest.go b/src/manifest.go
index c0bf482..508c12b 100644
--- a/src/manifest.go
+++ b/src/manifest.go
@@ -103,7 +103,7 @@ const ManifestSizeMax int = 1048576
 
 // Accepts a manifest with inline files, returns a manifest with external files after writing
 // file contents and the manifest itself to the storage.
-func StoreManifest(backend Backend, name string, manifest *Manifest) (*Manifest, error) {
+func StoreManifest(name string, manifest *Manifest) (*Manifest, error) {
 	extManifest := ExternalizeFiles(manifest)
 	extManifestData := EncodeManifest(extManifest)
 	if len(extManifestData) > ManifestSizeMax {
diff --git a/src/migrate.go b/src/migrate.go
new file mode 100644
index 0000000..ab0bdbb
--- /dev/null
+++ b/src/migrate.go
@@ -0,0 +1,97 @@
+package main
+
+import (
+	"fmt"
+	"io/fs"
+	"log"
+	"os"
+	"path/filepath"
+)
+
+func readToManifest(root *os.Root) (*Manifest, error) {
+	manifest := Manifest{}
+	manifest.Tree = make(map[string]*Entry)
+	err := fs.WalkDir(root.FS(), ".", func(path string, dirEntry fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+
+		manifestEntry := Entry{}
+		if dirEntry.IsDir() {
+			manifestEntry.Type = Type_Directory
+		} else if dirEntry.Type().IsRegular() {
+			data, err := root.ReadFile(path)
+			if err != nil {
+				return err
+			}
+			manifestEntry.Type = Type_InlineFile
+			manifestEntry.Size = int64(len(data))
+			manifestEntry.Data = data
+		} else if dirEntry.Type().Type() == fs.ModeSymlink {
+			target, err := root.Readlink(path)
+			if err != nil {
+				return err
+			}
+			manifestEntry.Type = Type_Symlink
+			manifestEntry.Size = int64(len(target))
+			manifestEntry.Data = []byte(target)
+		} else {
+			log.Println("migrate v1: illegal %s/%s", root.Name(), path)
+		}
+		if path == "." {
+			path = ""
+		}
+		manifest.Tree[path] = &manifestEntry
+		return nil
+	})
+	return &manifest, err
+}
+
+type ReadDirLinkFS interface { // aaaaahh!!! Why is Go like this!!
+	fs.ReadDirFS
+	fs.ReadLinkFS
+}
+
+func MigrateFromV1(root *os.Root) error {
+	data := root.FS().(ReadDirLinkFS)
+
+	domainDirEntries, err := data.ReadDir("www")
+	if err != nil {
+		return err
+	}
+
+	for _, domainDirEntry := range domainDirEntries {
+		domain := domainDirEntry.Name()
+		if !domainDirEntry.IsDir() {
+			return fmt.Errorf("migrate v1: www/%s: not a directory", domain)
+		}
+
+		projectDirEntries, err := data.ReadDir(filepath.Join("www", domain))
+		if err != nil {
+			return err
+		}
+
+		for _, projectDirEntry := range projectDirEntries {
+			projectName := projectDirEntry.Name()
+			if projectDirEntry.Type().Type() != fs.ModeSymlink {
+				return fmt.Errorf("migrate v1: www/%s/%s: not a symlink", domain, projectName)
+			}
+
+			treeRoot, err := root.OpenRoot(filepath.Join("www", domain, projectName))
+			if err != nil {
+				return err
+			}
+
+			manifest, err := readToManifest(treeRoot)
+			if err != nil {
+				return fmt.Errorf("migrate v1: read %s/%s: %w", domain, projectName, err)
+			}
+
+			_, err = StoreManifest(fmt.Sprintf("%s/%s", domain, projectName), manifest)
+			if err != nil {
+				return fmt.Errorf("migrate v1: store %s/%s: %w", domain, projectName, err)
+			}
+		}
+	}
+	return nil
+}
diff --git a/src/update.go b/src/update.go
index 0b38cab..e6dc69f 100644
--- a/src/update.go
+++ b/src/update.go
@@ -41,7 +41,7 @@ func Update(
 		err = fmt.Errorf("update timeout")
 	} else if err == nil {
 		oldManifest, _ = backend.GetManifest(webRoot)
-		newManifest, err = StoreManifest(backend, webRoot, fetchManifest)
+		newManifest, err = StoreManifest(webRoot, fetchManifest)
 		if err == nil {
 			if oldManifest == nil {
 				outcome = UpdateCreated