copy supports copying to primary storage with different dest key

Author: leafo

README.md

@@ -54,7 +54,7 @@ zipserver <command> --help    # Show help for a specific command
 |---------|-------------|---------|---------------|
 | `server` | Start HTTP server (default) | n/a | |
 | `extract` | Extract a zip file to storage | Source read, optional target write | `/extract` |
-| `copy` | Copy a file to target storage | Source read, target write | `/copy` |
+| `copy` | Copy a file to target storage or different key | Source read, target or source write | `/copy` |
 | `delete` | Delete files from storage | Target write | `/delete` |
 | `list` | List files in a zip archive | Source read, URL, or local file | `/list` |
 | `slurp` | Download a URL and store it | Source write, or optional target write | `/slurp` |
@@ -157,12 +157,19 @@ curl -X POST "http://localhost:8090/extract" \
 
 ## Copy
 
-Copy a file from primary storage to a target storage (e.g., S3).
+Copy a file from primary storage to a target storage, or to a different key within primary storage.
 
 **CLI:**
 ```bash
+# Copy to a target storage
 zipserver copy --key path/to/file.zip --target s3backup
 
+# Copy to a different key within primary storage (rename/move)
+zipserver copy --key path/to/file.zip --dest-key archive/file.zip
+
+# Copy to target storage with a different destination key
+zipserver copy --key path/to/file.zip --target s3backup --dest-key renamed.zip
+
 # With HTML footer injection
 zipserver copy --key games/123/index.html --target s3backup \
   --html-footer '<script src="/analytics.js"></script>'
@@ -173,6 +180,12 @@ zipserver copy --key games/123/index.html --target s3backup \
 # Sync mode (waits for completion)
 curl "http://localhost:8090/copy?key=path/to/file.zip&target=s3backup"
 
+# Copy within primary storage to a different key
+curl "http://localhost:8090/copy?key=path/to/file.zip&dest_key=archive/file.zip"
+
+# Copy to target with different destination key
+curl "http://localhost:8090/copy?key=path/to/file.zip&target=s3backup&dest_key=renamed.zip"
+
 # Async mode (returns immediately, notifies callback when done)
 curl "http://localhost:8090/copy?key=path/to/file.zip&target=s3backup&callback=http://example.com/done"
 
@@ -183,6 +196,8 @@ curl -X POST "http://localhost:8090/copy" \
   -d "html_footer=<script src=\"/analytics.js\"></script>"
 ```
 
+Either `target` or `dest_key` (or both) must be provided. When copying within the same storage (no `target`), `dest_key` must differ from `key`.
+
 ### HTML Footer Injection for Copy
 
 When copying files, you can inject an HTML snippet at the end of the file using the `html_footer` parameter.

main.go

@@ -51,9 +51,10 @@ var (
 	extractHtmlFooter   = extractCmd.Flag("html-footer", "HTML snippet to append to all index.html files").String()
 
 	// Copy command
-	copyCmd        = app.Command("copy", "Copy a file to target storage")
+	copyCmd        = app.Command("copy", "Copy a file to target storage or different key")
 	copyKey        = copyCmd.Flag("key", "Storage key to copy").Required().String()
-	copyTarget     = copyCmd.Flag("target", "Target storage name").Required().String()
+	copyDestKey    = copyCmd.Flag("dest-key", "Destination key (defaults to source key)").String()
+	copyTarget     = copyCmd.Flag("target", "Target storage name").String()
 	copyBucket     = copyCmd.Flag("bucket", "Expected bucket (optional verification)").String()
 	copyHtmlFooter = copyCmd.Flag("html-footer", "HTML snippet to append to copied file").String()
 
@@ -232,6 +233,7 @@ func runCopy(config *zipserver.Config) {
 
 	params := zipserver.CopyParams{
 		Key:            *copyKey,
+		DestKey:        *copyDestKey,
 		TargetName:     *copyTarget,
 		ExpectedBucket: *copyBucket,
 		HtmlFooter:     *copyHtmlFooter,

zipserver/copy_handler.go

@@ -13,31 +13,40 @@ import (
 
 var copyLockTable = NewLockTable()
 
-// Copy copies a file from primary storage to a target storage
+// Copy copies a file from primary storage to a target storage, or within primary
+// storage if no target is specified. If DestKey is set, the file is written to
+// that key; otherwise it uses the source Key.
 func (o *Operations) Copy(ctx context.Context, params CopyParams) CopyResult {
-	storageTargetConfig := o.config.GetStorageTargetByName(params.TargetName)
-	if storageTargetConfig == nil {
-		return CopyResult{Err: fmt.Errorf("invalid target: %s", params.TargetName)}
+	if err := params.Validate(o.config); err != nil {
+		return CopyResult{Err: err}
 	}
 
-	if storageTargetConfig.Readonly {
-		return CopyResult{Err: fmt.Errorf("target %s is readonly", params.TargetName)}
-	}
-
-	targetBucket := storageTargetConfig.Bucket
-
-	if params.ExpectedBucket != "" && params.ExpectedBucket != targetBucket {
-		return CopyResult{Err: fmt.Errorf("expected bucket does not match target bucket: %s != %s", params.ExpectedBucket, targetBucket)}
-	}
+	destKey := params.DestKeyOrKey()
 
+	// Create source storage (always primary)
 	storage, err := NewGcsStorage(o.config)
 	if err != nil {
 		return CopyResult{Err: fmt.Errorf("failed to create source storage: %v", err)}
 	}
 
-	targetStorage, err := storageTargetConfig.NewStorageClient()
-	if err != nil {
-		return CopyResult{Err: fmt.Errorf("failed to create target storage: %v", err)}
+	var targetStorage Storage
+	var targetBucket string
+	var targetLabel string
+
+	if params.TargetName == "" {
+		// Same-storage copy: reuse source storage for both read and write
+		targetStorage = storage
+		targetBucket = o.config.Bucket
+		targetLabel = "primary"
+	} else {
+		// Cross-storage copy: read from primary, write to target
+		storageTargetConfig := o.config.GetStorageTargetByName(params.TargetName)
+		targetBucket = storageTargetConfig.Bucket
+		targetStorage, err = storageTargetConfig.NewStorageClient()
+		if err != nil {
+			return CopyResult{Err: fmt.Errorf("failed to create target storage: %v", err)}
+		}
+		targetLabel = params.TargetName
 	}
 
 	startTime := time.Now()
@@ -73,23 +82,23 @@ func (o *Operations) Copy(ctx context.Context, params CopyParams) CopyResult {
 	}
 
 	if injected {
-		log.Print("Starting transfer (injected): [", params.TargetName, "] ", targetBucket, "/", params.Key, " ", opts)
+		log.Print("Starting transfer (injected): [", targetLabel, "] ", targetBucket, "/", destKey, " ", opts)
 	} else {
-		log.Print("Starting transfer: [", params.TargetName, "] ", targetBucket, "/", params.Key, " ", opts)
+		log.Print("Starting transfer: [", targetLabel, "] ", targetBucket, "/", destKey, " ", opts)
 	}
-	result, err := targetStorage.PutFile(ctx, targetBucket, params.Key, mReader, opts)
+	result, err := targetStorage.PutFile(ctx, targetBucket, destKey, mReader, opts)
 	if err != nil {
 		return CopyResult{Err: fmt.Errorf("failed to copy file: %v", err)}
 	}
 
 	globalMetrics.TotalCopiedFiles.Add(1)
-	log.Print("Transfer complete: [", params.TargetName, "] ", targetBucket, "/", params.Key,
+	log.Print("Transfer complete: [", targetLabel, "] ", targetBucket, "/", destKey,
 		", bytes read: ", formatBytes(float64(mReader.BytesRead)),
 		", duration: ", mReader.Duration.Seconds(),
 		", speed: ", formatBytes(mReader.TransferSpeed()), "/s")
 
 	return CopyResult{
-		Key:      params.Key,
+		Key:      destKey,
 		Duration: fmt.Sprintf("%.4fs", time.Since(startTime).Seconds()),
 		Size:     mReader.BytesRead,
 		Md5:      result.MD5,
@@ -153,8 +162,9 @@ func notifyError(callbackURL string, err error) error {
 	return notifyCallback(callbackURL, message)
 }
 
-// The copy handler will asynchronously copy a file from primary storage to the
-// storage specified by target
+// The copy handler asynchronously copies a file from primary storage to either:
+// - A target storage (when target is specified)
+// - A different key within primary storage (when only dest_key is specified)
 func copyHandler(w http.ResponseWriter, r *http.Request) error {
 	if err := r.ParseForm(); err != nil {
 		return fmt.Errorf("failed to parse form: %w", err)
@@ -166,21 +176,30 @@ func copyHandler(w http.ResponseWriter, r *http.Request) error {
 	}
 
 	callbackURL := params.Get("callback")
+	targetName := params.Get("target")
+	destKey := params.Get("dest_key")
 
-	targetName, err := getParam(params, "target")
-	if err != nil {
+	expectedBucket, _ := getParam(params, "bucket")
+	htmlFooter := params.Get("html_footer")
+
+	copyParams := CopyParams{
+		Key:            key,
+		DestKey:        destKey,
+		TargetName:     targetName,
+		ExpectedBucket: expectedBucket,
+		HtmlFooter:     htmlFooter,
+	}
+	if err := copyParams.Validate(globalConfig); err != nil {
 		return err
 	}
 
-	storageTargetConfig := globalConfig.GetStorageTargetByName(targetName)
-	if storageTargetConfig == nil {
-		return fmt.Errorf("invalid target: %s", targetName)
+	// Use dest_key for lock if provided, otherwise use key
+	lockDestKey := copyParams.DestKeyOrKey()
+	lockTargetName := targetName
+	if lockTargetName == "" {
+		lockTargetName = "primary"
 	}
-
-	expectedBucket, _ := getParam(params, "bucket")
-	htmlFooter := params.Get("html_footer")
-
-	lockKey := fmt.Sprintf("%s:%s", targetName, key)
+	lockKey := fmt.Sprintf("%s:%s", lockTargetName, lockDestKey)
 
 	hasLock := copyLockTable.tryLockKey(lockKey)
 
@@ -190,13 +209,6 @@ func copyHandler(w http.ResponseWriter, r *http.Request) error {
 	}
 
 	ops := NewOperations(globalConfig)
-	copyParams := CopyParams{
-		Key:            key,
-		TargetName:     targetName,
-		ExpectedBucket: expectedBucket,
-		HtmlFooter:     htmlFooter,
-	}
-
 	// sync codepath
 	if callbackURL == "" {
 		defer copyLockTable.releaseKey(lockKey)