App Engine在Go中读取本地文件

Im using go and cloud endpoints and i have a pem file that im using him in order to create signed URL.
When im running my app locally and im providing a full path to the ioutil.ReadFile method its working well.

On the server i tried several option on server like this but i get file not found...

APPNAME/files/key.pem
  1. What is the correct path to the file?

  2. Should i use memcached instead of ioutil.ReadFile for reading the pem file ?

App Engine applications run with CWD set to the root of the application (the directory containing app.yaml). If your application has the directory structure

- APPNAME
 - files
  - key.pem
 - app.yaml

then use the path files/key.pem to open the file.

If the .pem file is part of your application's static data, then it's best to read the data from the file system.