dify-sandbox/FAQ.md

FAQ

1. Why does my Python code throw an exception like "xxx.so: cannot open shared object file: No such file or directory"?

This occurs because the dify-sandbox implementation generates a temporary file in the /var/sandbox/sandbox-python/ directory to save and execute your Python code. Before running your Python code, it uses syscall.Chroot to restrict the current process's root to the /var/sandbox/sandbox-python/ directory. This directory structure, visible to the Python process, determines all the Python modules/packages that can be imported, including modules based on C code.

• Root: /var/sandbox/sandbox-python/ is the root directory from the Python process perspective. Its subdirectories depend on the python_lib_path configuration in your config.yaml. Usually, it includes:
  • etc/ directory
  • python.so shared object, compiled and built by dify-sandbox
  • usr/lib directory
  • usr/local/

If you haven't configured python_lib_path, dify-sandbox will default to the following settings (see code internal/static/config_default_amd64.go; for ARM systems, see config_default_arm64.go):

var DEFAULT_PYTHON_LIB_REQUIREMENTS = []string{
    "/usr/local/lib/python3.10", // Usually your Python installation directory; if using conda, modify this to the conda virtual environment root directory, e.g., /root/anaconda3/envs/{env_name}
    "/usr/lib/python3.10",
    "/usr/lib/python3",
    "/usr/lib/x86_64-linux-gnu/libssl.so.3", // Your Python code's shared object dependency; it will be copied to /var/sandbox/sandbox-python/usr/lib/x86_64-linux-gnu/, and your Python process will load it from /usr/lib/x86_64-linux-gnu/
    "/usr/lib/x86_64-linux-gnu/libcrypto.so.3", // Similar to above
    "/etc/ssl/certs/ca-certificates.crt",
    "/etc/nsswitch.conf",
    "/etc/hosts",
    "/etc/resolv.conf",
    "/run/systemd/resolve/stub-resolv.conf",
    "/run/resolvconf/resolv.conf",
}

So, when encountering such errors, you need to modify the python_lib_path in your config.yaml to include the shared object paths required by your Python code.

Note: The Go process initializes this environment at startup, so if you configure too many python_lib_path, the startup will be very slow. For serverless environments, consider modifying the code to complete this build in a Docker container.

2. My Python code returns an "operation not permitted" error?

dify-sandbox uses Linux seccomp to restrict system calls. It’s recommended to read the source code (internal/core/lib/python/add_seccomp.go). When you encounter this error, it usually means your code executed a restricted system call. The default allowed system calls are configured in syscalls_amd64. You can modify this according to your system’s needs (currently, it cannot be modified through the configuration file).

To quickly identify the system calls your Python code depends on, here are two recommended methods:

Method 1: Using strace to log all the system calls

1. Write a test Python file, for example, test_numpy.py, and add a line of code to import numpy:

   import numpy as np
   

2. Use strace to log all the system calls:

   strace -o strace_output.txt -e trace=all python test_numpy.py
   

3. Use awk and sort to print all the system calls:

   awk '{print $1}' strace_output.txt | sed 's/[(].*//' | sort | uniq -c | sort -nr
   

   Then, get the list of system calls, diff, and add:

       831 stat
       418 fstat
       393 read
       337 lseek
       278 openat
       250 close
       215 mmap
       180 ioctl
        68 rt_sigaction
        60 mprotect
        54 getdents64
        42 brk
        35 futex
        18 pread64
        17 munmap
         7 clone
         6 lstat
         4 readlink
         3 uname
         3 dup
         2 shmget
         2 getuid
         2 getgid
         2 geteuid
         2 getegid
         2 getcwd
         2 arch_prctl
         1 sysinfo
         1 shmdt
         1 shmat
         1 set_tid_address
         1 set_robust_list
         1 sched_getaffinity
         1 rt_sigprocmask
         1 prlimit64
         1 gettid
         1 fcntl
         1 exit_group
         1 execve
         1 epoll_create1
         1 access
   

Method 2: Using dify-sandbox test code to scan and output all system calls

1. Modify the /cmd/test/syscall_dig/test.py Python code to append your test codes to the end of this file.
2. Run go run cmd/test/syscall_dig/main.go to get the required system calls.