Summary
The issue at hand is a 412 Precondition Failed error when attempting to upload an asset to Hygraph using a signed URL. The error occurs despite following the official documentation and including the required headers in the request.
Root Cause
The root cause of this issue is likely due to:
- Missing or incorrect headers in the request
- Invalid or expired signature in the request
- Mismatch between the request method and the expected method (e.g., using POST instead of PUT)
Why This Happens in Real Systems
This issue can occur in real systems due to:
- Inadequate documentation or unclear requirements
- Incorrect implementation of the upload process
- Changes to the API or backend that are not reflected in the documentation
Real-World Impact
The impact of this issue can be significant, including:
- Failed uploads and lost data
- Increased latency and decreased performance
- Frustrated users and decreased user experience
Example or Code
const uploadResponse = await fetch(
createAsset.upload.requestPostData.url,
{
method: "POST",
headers: {
"X-Amz-Date": createAsset.upload.requestPostData.date,
"key": createAsset.upload.requestPostData.key,
"X-Amz-Signature": createAsset.upload.requestPostData.signature,
"X-Amz-Algorithm": createAsset.upload.requestPostData.algorithm,
"policy": createAsset.upload.requestPostData.policy,
"X-Amz-Credential": createAsset.upload.requestPostData.credential,
"X-Amz-Security-Token": createAsset.upload.requestPostData.securityToken,
"Content-Type": photoFile.type, // Add the Content-Type header
},
body: photoFile,
}
);How Senior Engineers Fix It
Senior engineers can fix this issue by:
- Verifying the request headers and ensuring they match the expected headers
- Checking the signature and ensuring it is valid and not expired
- Using the correct request method (e.g., PUT instead of POST)
- Adding the Content-Type header to the request
Why Juniors Miss It
Juniors may miss this issue due to:
- Lack of experience with API uploads and signed URLs
- Inadequate understanding of the requirements and documentation
- Insufficient testing and debugging of the upload process