Fixing Executable File Permissions After Deployment to Posit Connect

Overview

When deploying applications to Posit Connect that include executable files (e.g., compiled binaries, shell scripts), you may encounter a situation where those files lose their executable permissions after deployment. This can result in errors like the following when using subprocess.run() in Python:

FileNotFoundError: [Errno 2] No such file or directory: './executable_file'

This guide outlines why this happens and provides two common solutions depending on your Connect environment.

Why This Happens

When content is deployed to Posit Connect, the system does not retain the original file permissions (including the executable bit) from your local machine. This means that even if a file is marked executable before deployment (e.g., with chmod +x), that permission may not carry over once the bundle is unpacked on the server.

As a result, applications that rely on launching binaries or shell scripts may fail at runtime unless the file's executable permissions are restored.

For Self-Managed Connect Servers (With OS Access)

If you have administrative access to the Connect server, you can manually restore the executable bit after deployment:

sudo chmod +x /opt/rstudio-connect/mnt/app/your_executable

Replace your_executable with the name of the file you need to execute.

For Posit-Hosted Connect or When OS Access Is Unavailable

If you do not have access to the server’s file system (e.g., in a Posit-hosted Connect environment), you can programmatically restore permissions within your application using one of the following methods:

Option 1: Set executable permissions at runtime in Python

import os
import shutil
import subprocess

# Copy the binary to a writable location
shutil.copy('./your_executable', '/tmp/your_executable')

# Set the executable bit
os.chmod('/tmp/your_executable', 0o755)

# Call the binary using subprocess
subprocess.run(['/tmp/your_executable'])

Option 2: Use a wrapper script

Create a shell script (e.g., launch.sh) that sets permissions and then calls the binary:

#!/bin/bash
chmod +x ./your_executable
./your_executable "$@"

Then invoke launch.sh from your app using subprocess.

Still running into issues?

If these workarounds don’t resolve the issue or your use case is more complex, feel free to open a support ticket so we can help troubleshoot further.