{"record":{"id":"5ca01a4d90b4d81c","repo":"vxcontrol/pentagi","slug":"container-file-transfer-failed-w","errorCode":null,"errorMessage":"container file transfer failed: %w","messagePattern":"container file transfer failed: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"backend/pkg/tools/terminal.go","lineNumber":492,"sourceCode":"\t\treturn fmt.Errorf(\"tar archive header generation failed: %w\", err)\n\t}\n\n\t_, err = archiveWriter.Write([]byte(content))\n\tif err != nil {\n\t\treturn fmt.Errorf(\"tar archive content serialization failed: %w\", err)\n\t}\n\n\terr = archiveWriter.Close()\n\tif err != nil {\n\t\treturn fmt.Errorf(\"failed to close tar writer: %w\", err)\n\t}\n\n\tdir := filepath.Dir(path)\n\terr = t.dockerClient.CopyToContainer(ctx, containerName, dir, tarBuffer, client.CopyToContainerOptions{\n\t\tAllowOverwriteDirWithFile: true,\n\t})\n\tif err != nil {\n\t\treturn fmt.Errorf(\"container file transfer failed: %w\", err)\n\t}\n\n\treturn nil\n}\n\n// EditFile applies a unified diff to the file at path: it reads the current\n// content, applies the diff to it entirely in memory (see applyUnifiedDiff),\n// and only if every hunk applied cleanly writes the result back - a diff\n// that doesn't fully apply leaves the file untouched.\nfunc (t *terminal) EditFile(ctx context.Context, flowID int64, path, diffText string) (string, error) {\n\tif path == \"\" {\n\t\treturn \"\", fmt.Errorf(\"path is required and cannot be empty\")\n\t}\n\tif strings.TrimSpace(diffText) == \"\" {\n\t\treturn \"\", fmt.Errorf(\"diff is required and cannot be empty\")\n\t}\n\n\tcurrent, err := t.readFileFromContainer(ctx, flowID, path)","sourceCodeStart":474,"sourceCodeEnd":510,"githubUrl":"https://github.com/vxcontrol/pentagi/blob/ea665308baaff015b226f308438a68d929d0f29b/backend/pkg/tools/terminal.go#L474-L510","documentation":"This is the real docker-side failure: CopyToContainer failed to stream the finished tar buffer into the flow container at filepath.Dir(path). Common wrapped causes are: no such container, container not running, no such directory in the container, path is not a directory, permission denied, or connection problems to the Docker daemon. It is raised by WriteFile and EditFile whenever the in-container destination directory is missing or inaccessible.","triggerScenarios":"Writing to a path whose parent directory does not exist in the container (CopyToContainer does not mkdir -p); writing into a read-only filesystem or a directory the container user cannot write; the flow container was stopped/removed between the IsContainerRunning check and the copy; Docker daemon connection drop.","commonSituations":"Agent tools writing to /tmp/subdir/file.txt where subdir was never created; writing to bind-mounted read-only volumes; container killed mid-flow; DOCKER_HOST misconfiguration or daemon restart.","solutions":["Create the parent directory inside the container first (e.g. exec `mkdir -p <dir>` via the terminal tool) before writing the file","Confirm the container is running: docker ps / IsContainerRunning, and restart the flow container if it stopped","Check that the destination path is not on a read-only mount and the container user has write permission","Verify Docker daemon connectivity from the backend (docker info); fix DOCKER_HOST/socket permissions","Inspect the wrapped %w cause for the exact Docker API error (e.g. 'no such directory', 'permission denied')"],"exampleFix":"// before\ndir := filepath.Dir(path)\nerr = t.dockerClient.CopyToContainer(ctx, containerName, dir, tarBuffer, client.CopyToContainerOptions{\n    AllowOverwriteDirWithFile: true,\n})\n// after\nif err := t.ensureDirExists(ctx, containerName, filepath.Dir(path)); err != nil { // runs `mkdir -p` via exec\n    return fmt.Errorf(\"failed to ensure directory %s: %w\", filepath.Dir(path), err)\n}\nerr = t.dockerClient.CopyToContainer(ctx, containerName, filepath.Dir(path), tarBuffer, client.CopyToContainerOptions{\n    AllowOverwriteDirWithFile: true,\n})","handlingStrategy":"validation","validationCode":"// Ensure the parent dir exists in the container before writing\nout, err := term.ExecuteCommand(ctx, flowID, fmt.Sprintf(\"test -d %s && echo OK\", filepath.Dir(path)))\nif !strings.Contains(out, \"OK\") {\n    if _, err := term.ExecuteCommand(ctx, flowID, fmt.Sprintf(\"mkdir -p %s\", filepath.Dir(path))); err != nil {\n        return err\n    }\n}","typeGuard":null,"tryCatchPattern":"if _, err := term.WriteFile(ctx, flowID, content, path); err != nil {\n    if strings.Contains(err.Error(), \"container file transfer failed\") {\n        // inspect errors.Unwrap(err) for Docker API cause:\n        // 'no such directory' → mkdir first; 'is not running' → restart container\n    }\n}","preventionTips":["Always mkdir -p the parent directory before writing new paths","Check docker ps and container health before long agent runs","Never write to read-only mounts (/proc, /sys, RO volumes)","Keep Docker daemon socket/DOCKER_HOST connectivity verified"],"tags":["docker","copy-to-container","file-transfer","network"],"backgroundTag":"docker-copy-to-container-failed","analyzedSha":"ea665308baaff015b226f308438a68d929d0f29b","analyzedAt":"2026-09-01T14:16:31.421Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}