Wormhole CLI Upload Errors: Fixing Advance Share URL Issues

Understanding the "B2 Upload Failed (503)" Error in Wormhole CLI

Have you ever encountered that frustrating "B2 upload failed" error, specifically with a HTTP status server error (503) when using the Wormhole CLI? It's a common hiccup, especially when you're trying to get a jump on things by obtaining the shareurl in advance before your upload is even complete. This premature retrieval of the shareable link can throw a wrench in the works, causing the downloader to hit a wall when it tries to access the resource. The 503 Service Unavailable error from Backblaze B2, the backend storage for Wormhole, indicates that the server is temporarily unable to handle the request. This usually happens because the file isn't fully uploaded or processed yet, and the shareurl points to a resource that doesn't exist or isn't ready for public access. It's like trying to send someone the address to a party before the house is even built – they won't be able to get in! The Wormhole CLI, in its eagerness to provide you with that useful link, might be fetching it too early in the upload process. This can lead to a race condition where the download process starts before the upload process has fully concluded, resulting in this error. It’s crucial to understand that the shareurl is generated after the file has been successfully and completely transferred to the storage. Attempting to use it before that point is akin to asking for a key to a house that’s still under construction. The underlying Backblaze B2 service, upon receiving a request for a file that isn't ready, correctly responds with a 503 error, signaling that the resource is temporarily unavailable. This behavior is by design to prevent data corruption or incomplete downloads. Therefore, when troubleshooting this specific error, the primary focus should always be on the timing of the shareurl retrieval relative to the completion of the file upload.

The Mechanics of Wormhole CLI Uploads and Share URLs

To truly grasp why obtaining the shareurl in advance causes issues, let's delve a bit deeper into the mechanics of how Wormhole CLI handles uploads. When you initiate an upload using the Wormhole CLI, it doesn't just magically send your file off into the ether. Instead, it orchestrates a multi-step process involving your local machine, the Wormhole servers (which manage the metadata and temporary rendezvous points), and the backend storage provider, in this case, Backblaze B2. The process typically begins with the CLI preparing your file for transfer. It then communicates with the Wormhole relay servers to get the necessary information to initiate the upload to Backblaze B2. This involves generating unique identifiers and potentially pre-signed URLs provided by Backblaze B2 to facilitate direct uploads. Once the file data starts streaming to Backblaze B2, a record is created in the Wormhole system, and a temporary shareurl is generated. However, this shareurl only becomes fully functional and points to a complete, downloadable file after the entire upload process has been successfully completed and verified by Backblaze B2. The error HTTP status server error (503) arises when the shareurl is requested or used before this final verification step. The downloader, upon receiving the shareurl, attempts to access it. If the file is still in the process of being uploaded or hasn't been finalized by Backblaze B2, the server at that URL will respond with a 503 error, indicating that the content isn't ready to be served. It’s important to distinguish between the generation of a shareurl and its activation. The CLI might generate a placeholder shareurl early on as part of its process, but it's not truly