upic配置不成功

[icret]

upic配置不成功

[JJPro]

@hyhy01 @icret Holy shit, I got it working in uPic.

You have to specify Content-Type as multipart/form-data in request header. Otherwise, it will send the data, including the file, as pure JSON.

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The following is my debug journey and postmortem:

First, I checked nginx log to make sure that the server is getting the request. And that's a check.
Then I want to see what the server returns to uPic like so:
I tried to search for uPic logs, but I couldn't find its log file, nor any marks in system logs.
So I decided to capture the network traffic with tcpdump, then use Wireshark to analyze the traffic.
There, I can see that easyimage server sends the following message back to uPic:

{
    "result": "failed",
    "code": 204,
    "message": "没有选择上传的文件"
}

Hmmm, interesting.

Then I analyzed traffic from curl and Postman as well for comparison.
There I can see that, both curl and Postman is sending the request as type multipart/form-data, while uPic is doing that via application/json, which is a sub-type of html/text.
Aha! I was like, WHAT?! uPic, how dare you send a file via json.

这件事对于开发人员的经验/教训:

1. When sending a file, never forget to attach header Content-type: multipart/form-data to the request. For form submission, browser will auto specify the correct Content-type, but in REST/Ajax calls, we developers have to manually specify the correct Content-type for use.
2. @icret At this moment, easyimage is returning HTTP status code 200 (OK) in the above situation, I believe it is more appropriate to return 400 (Bad Request) instead. With that, apps like uPic will be able to properly detect and handle the error, and probably show an error popup to inform its user.