https://cloud.google.com/functions/docs/concepts/exec#file_system
The only writeable part of the filesystem is the /tmp directory, which you can use to store temporary files in a function instance. This is a local disk mount point known as a "tmpfs" volume in which data written to the volume is stored in memory. Note that it will consume memory resources provisioned for the function.
The rest of the file system is read-only and accessible to the function.
https://cloud.google.com/functions/docs/bestpractices/tips#always_delete_temporary_files
Local disk storage in the temporary directory is an in-memory filesystem. Files that you write consume memory available to your function, and sometimes persist between invocations. Failing to explicitly delete these files may eventually lead to an out-of-memory error and a subsequent cold start.
import osdef test_read_write_tmp(requests): file_path = '/tmp/test' content = 'Hello World' # make sure dir exist os.makedirs(os.path.dirname(file_path), exist_ok=True) with open(file_path, 'wb') as f: f.write(content) if os.path.exists(file_path): with open(file_path, 'rb') as f: content = f.read() return content