Skip to content

fix: stream ZIP downloads directly to response to prevent OOM #369

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
sridhar-3009 wants to merge 1 commit into
base: main
Choose a base branch
from
+15 −22
Open

fix: stream ZIP downloads directly to response to prevent OOM #369

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
37 changes: 15 additions & 22 deletions backend/pkg/server/services/flow_files.go
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,6 @@
package services

import (
"bytes"
"context"
"errors"
"fmt"
Expand Down Expand Up @@ -547,43 +546,37 @@ func (s *FlowFileService) DownloadFlowFile(c *gin.Context) {
}

// Single directory → ZIP with paths relative to that directory (backward-compat).
// The archive is buffered so an explicit Content-Length can be set; this allows
// clients (including Swagger UI) to recognise and download the file correctly.
// Written directly to the response writer to avoid buffering the entire archive
// in memory, which can OOM the server for large directories.
if len(entries) == 1 && entries[0].info.IsDir() {
name := filepath.Base(entries[0].localPath)
var buf bytes.Buffer
if err := flowfiles.ZipDirectory(&buf, entries[0].localPath); err != nil {
c.Header("Content-Type", "application/zip")
c.Header("Content-Disposition", mime.FormatMediaType("attachment", map[string]string{
"filename": name + ".zip",
}))
c.Status(http.StatusOK)
if err := flowfiles.ZipDirectory(c.Writer, entries[0].localPath); err != nil {
logger.FromContext(c).WithError(err).WithField("flow_id", flowID).Error("error creating ZIP archive")
response.Error(c, response.ErrInternal, err)
return
}
c.DataFromReader(http.StatusOK, int64(buf.Len()), "application/zip", &buf,
map[string]string{
"Content-Disposition": mime.FormatMediaType("attachment", map[string]string{
"filename": name + ".zip",
}),
})
return
}

// Multiple paths (any mix of files and directories) → ZIP with cache-relative paths.
// Buffered for the same reason as above.
// Streamed directly to the response writer for the same reason as above.
relPaths := make([]string, 0, len(entries))
for _, e := range entries {
relPaths = append(relPaths, filepath.ToSlash(e.reqPath))
}
var buf bytes.Buffer
if err := flowfiles.ZipRelativePaths(&buf, s.flowDataDir(flowID), relPaths); err != nil {
c.Header("Content-Type", "application/zip")
c.Header("Content-Disposition", mime.FormatMediaType("attachment", map[string]string{
"filename": "download.zip",
}))
c.Status(http.StatusOK)
if err := flowfiles.ZipRelativePaths(c.Writer, s.flowDataDir(flowID), relPaths); err != nil {
logger.FromContext(c).WithError(err).WithField("flow_id", flowID).Error("error creating ZIP archive")
response.Error(c, response.ErrInternal, err)
return
}
c.DataFromReader(http.StatusOK, int64(buf.Len()), "application/zip", &buf,
map[string]string{
"Content-Disposition": mime.FormatMediaType("attachment", map[string]string{
"filename": "download.zip",
}),
})
}

// PullFlowFiles is a function to sync one or more paths from the container into the local cache
Expand Down