Calibre-Web: Fix Incorrect Downloaded Filenames

by Alex Johnson 48 views

Experiencing issues with incorrect filenames when downloading books in Calibre-Web? This article addresses a bug report where users have encountered downloaded files with wrong names. Let's dive into the details of this issue, the steps to reproduce it, and the environment in which it occurs.

Bug Description

The core problem lies in the fact that the downloaded filenames do not match the expected or correct names of the books being downloaded. This can lead to confusion and difficulty in managing your ebook library.

Steps to Reproduce

To replicate this bug, follow these steps:

  1. Search for a specific book title, for example, "肖申克的救赎" (The Shawshank Redemption).
  2. Click on the first download link or option presented for that book.

After performing these steps, the expectation is that the downloaded file should bear a name related to "肖申克的救赎" or "The Shawshank Redemption". However, the bug results in a different, incorrect filename.

Debug Information and Environment

The user has provided valuable debug information to help diagnose the problem. This includes:

  • A debug zip file: cwa-book-downloader-debug_BUILD-2025-11-06-8ea2fee0bbdfdff225a313b95e495b5ba15faf6d_RELEASE-v0.2.4_20251114-110710.zip

  • Operating System: XUbuntu 24.04

  • Docker Compose Configuration:

    The docker-compose.yml file provides insights into the user's setup, including the use of calibre-web-automated-book-downloader-extbp and flaresolverr images. The configuration specifies environment variables such as FLASK_PORT, LOG_LEVEL, BOOK_LANGUAGE, USE_BOOK_TITLE, TZ, APP_ENV, UID, GID, and EXT_BYPASSER_URL. It also defines port mappings, volumes, and proxy settings. The EXT_BYPASSER_URL is set to http://flaresolverr:8191, indicating that the user is using FlareSolverr to bypass anti-bot measures. The proxy settings suggest that the user is routing traffic through a proxy server. The volumes map /tmp/data/calibre-web/ingest to /cwa-book-ingest and /cwa/config/path/app.db to /auth/app.db. These mappings are essential for Calibre-Web to access the downloaded books and authentication details. All the above configurations help understand and recreate the context under which the error happens. It is extremely helpful to solve the problem. The information of docker compose is crucial for debugging and fixing the error that the user encountered. This could involve examining how the application interacts with FlareSolverr or how it handles filenames when downloading books through a proxy.

Analyzing the Issue

Based on the information provided, several factors could be contributing to the incorrect filename issue:

  1. Encoding Problems: The filename might be getting corrupted due to encoding issues, especially if the book title contains non-ASCII characters (as seen in the example title "肖申克的救赎").
  2. URL Parsing: The application might be incorrectly parsing the URL from which the book is downloaded, leading to a mangled filename.
  3. Server-Side Filename Generation: The server providing the book might be generating incorrect filenames, which are then passed on to the client.
  4. Caching Issues: In certain cases, caching mechanisms may interfere with proper filename retrieval, leading to outdated or incorrect data being used during the download process.
  5. Proxy Interference: The proxy server might be modifying the filename during the download process. This could be due to misconfiguration or compatibility issues between the proxy and the application. Analyzing the proxy's logs and configuration may provide valuable insights into whether it is affecting the filename.

Debugging Steps

To further investigate and resolve this issue, consider the following debugging steps:

  • Examine the Debug Zip: Carefully analyze the contents of the provided debug zip file. This file likely contains logs and other diagnostic information that can shed light on the source of the problem.
  • Check Encoding Settings: Ensure that all components of the system, including Calibre-Web, the operating system, and any relevant libraries, are using consistent encoding settings (e.g., UTF-8).
  • Inspect Network Traffic: Use tools like Wireshark or tcpdump to capture network traffic during the download process. This can help you examine the raw HTTP requests and responses and identify any issues with the filename being transmitted.
  • Test Without Proxy: Temporarily disable the proxy server to see if the issue persists. This can help determine whether the proxy is contributing to the problem.
  • Review Calibre-Web Configuration: Double-check the Calibre-Web configuration settings to ensure that filenames are being handled correctly.
  • Update Calibre-Web: Ensure that you are running the latest version of Calibre-Web. Software updates often include bug fixes and improvements that could resolve this issue.

Potential Solutions

Here are some potential solutions to address the incorrect filename issue:

  • Implement Filename Sanitization: Add code to sanitize filenames, removing or replacing any characters that could cause problems.
  • Use a Consistent Encoding: Ensure that all components of the system are using a consistent encoding (e.g., UTF-8) to prevent character corruption.
  • Properly Parse URLs: Implement robust URL parsing logic to extract the correct filename from the download URL.
  • Investigate and Configure Proxy Settings: Carefully review and configure the proxy settings to ensure that it is not interfering with the download process or modifying filenames. Consult the proxy's documentation or support resources for guidance on proper configuration.
  • Implement Error Handling: Add error handling to catch any exceptions that occur during the filename retrieval process and log them for further analysis.

Additional Notes

  • The user has set USE_BOOK_TITLE: true, which indicates that they want Calibre-Web to use the book title for the filename. This setting should be considered when debugging the issue.
  • The user is using FlareSolverr, which suggests that they are downloading books from websites that employ anti-bot measures. This could be a factor in the filename issue.
  • The problem could be in Calibre-Web, FlareSolverr or the interaction between the two.

Conclusion

Dealing with incorrect filenames can be a frustrating experience. By understanding the potential causes and following the debugging steps outlined in this article, you can effectively diagnose and resolve this issue in Calibre-Web. Remember to analyze the debug information, check encoding settings, inspect network traffic, and test without a proxy to pinpoint the root cause. With a systematic approach, you can restore the correct filenames and maintain an organized ebook library.

For more information on debugging network issues, visit this link to Wireshark documentation.