Troubleshooting
Read-only file system or Permission denied Error
This occurs because Leapcell prioritizes ultra-fast cold start performance, and as a result, only the /tmp directory is writable. All other directories are read-only. If your application needs to write files, ensure they are written to the /tmp directory.
For more details, refer to the Storage Documentation.
Shared Memory: /dev/shm Permission Denied
Similar to the above issue, /dev/shm is also read-only in the Leapcell environment. Therefore, shared memory via /dev/shm is not supported.
Leapcell recommends using pipes or sockets for inter-process communication instead.
Response is bigger than the maximum allowed size
Leapcell limits the response size to a maximum of 6 MB. If your application needs to return data larger than this limit, consider storing the data in an object storage solution and returning the object’s URL instead.
Port Some(8080) is not being listened to by the service
This issue typically occurs when your application is not listening on the correct port. Ensure the port your application is configured to listen on matches the one specified in the Settings.
Execution Environment User vs. Build Environment User Mismatch
During the build phase, the user has root-level permissions. However, in the execution environment, the application runs as a non-root user. If certain operations require root permissions during build time, ensure they are adapted to work under the execution environment’s constraints.