Hello,
I understand that you are trying to read a JSON file from a Go application that is hosted on App Engine.
The error message [1] that you are seeing can be due mainly to two reasons:
1 - The file does not exist in the filesystem.
2 - The file exists in the filesystem but the given path is wrong.
Please note that the App Engine documentation [2] states that static files are uploaded and handled separately from application files.
This means that if you have a file which you want to read from your Go code, the file must not match any static file pattern and cannot be in a folder defined as a static directory, or else the file will be considered to be a static file and will not be deployed along with your application code.
I can see that the Stackoverflow question [3] has already an answer that was upvoted a by a community user. Please let me know if the answer correctly addresses your issue and whether it helps you.
Thank you!
[1]: error loading config file: open go-config.json: no such file or directory