Reading and Writing Temporary Files

While Cloud Storage is the recommended solution for reading and writing files in App Engine, if your app only needs to write temporary files, you can use standard Go 1.11 methods to write files to a directory named /tmp.

All files in this directory are stored in the instance's RAM, therefore writing to /tmp takes up system memory. In addition, files in the /tmp directory are only available to the app instance that created the files. When the instance is deleted, the temporary files are deleted.

Golang provides the TempDir and TempFile methods that read and write files to your app instance's /tmp directory by default.