Exec Plugin🔗

The Exec plugin for vAccel implements a backend to call functions from external libraries using vAccel operations.

Warning

This plugin enables users to call functions from arbitrary libraries. Use it only on environments where the users are trusted.

Supported operations🔗

Installing the plugin🔗

The plugin comes bundled with the core vAccel installation. Find out more on how to install vAccel at the Installation page.

Usage🔗

To specify Exec plugin as the selected plugin for vAccel execution:

export VACCEL_PLUGINS=libvaccel-exec.so

Ensure vAccel and the Exec plugin libraries are in the library search paths before trying to use the plugin.

Running an example🔗

Export the necessary variables for the plugin:

export VACCEL_PLUGINS=libvaccel-exec.so
# Optionally, for verbose output
export VACCEL_LOG_LEVEL=4

Assuming pkg-config is available, you can call mytestfunc from the provided libmytestlib.so with:

$ exec_with_resource "$(pkg-config --variable=libdir vaccel)/libmytestlib.so"
2026.04.29-14:45:52.60 - <debug> Initializing vAccel
2026.04.29-14:45:52.60 - <info> vAccel 0.7.1-93-ebc23b1f
2026.04.29-14:45:52.60 - <debug> Config:
2026.04.29-14:45:52.60 - <debug>   plugins = libvaccel-exec.so
2026.04.29-14:45:52.60 - <debug>   log_level = debug
2026.04.29-14:45:52.60 - <debug>   log_file = (null)
2026.04.29-14:45:52.60 - <debug>   profiling_enabled = false
2026.04.29-14:45:52.60 - <debug>   version_ignore = false
2026.04.29-14:45:52.60 - <debug> Created top-level rundir: /run/user/0/vaccel/WHJlSC
2026.04.29-14:45:52.60 - <info> Registered plugin exec 0.7.1-93-ebc23b1f
2026.04.29-14:45:52.60 - <debug> Registered op noop from plugin exec
2026.04.29-14:45:52.60 - <debug> Registered op exec from plugin exec
2026.04.29-14:45:52.60 - <debug> Registered op exec_with_resource from plugin exec
2026.04.29-14:45:52.60 - <debug> Loaded plugin exec from libvaccel-exec.so
2026.04.29-14:45:52.60 - <warn> Path does not seem to have a `<prefix>://`
2026.04.29-14:45:52.60 - <warn> Assuming /usr/local/lib/x86_64-linux-gnu/libmytestlib.so is a local path
2026.04.29-14:45:52.60 - <debug> Initialized resource 1
2026.04.29-14:45:52.60 - <debug> New rundir for session 1: /run/user/0/vaccel/WHJlSC/session.1
2026.04.29-14:45:52.60 - <debug> Initialized session 1 with plugin exec
Initialized session with id: 1
2026.04.29-14:45:52.60 - <debug> New rundir for resource 1: /run/user/0/vaccel/WHJlSC/resource.1
2026.04.29-14:45:52.60 - <debug> session:1 Registered resource 1
2026.04.29-14:45:52.60 - <debug> New rundir for resource 2: /run/user/0/vaccel/WHJlSC/resource.2
2026.04.29-14:45:52.60 - <debug> Persisting file lib.so to /run/user/0/vaccel/WHJlSC/resource.2/lib.so
2026.04.29-14:45:52.60 - <debug> Initialized resource 2
2026.04.29-14:45:52.60 - <debug> session:1 Registered resource 2
2026.04.29-14:45:52.60 - <debug> session:1 Looking for func implementing op exec_with_resource
2026.04.29-14:45:52.60 - <debug> Returning func for op exec_with_resource from plugin exec
2026.04.29-14:45:52.60 - <debug> [exec] session:1 Calling exec_with_resource
2026.04.29-14:45:52.60 - <debug> [exec] Number of libraries: 1
2026.04.29-14:45:52.60 - <debug> [exec] Library: /usr/local/lib/x86_64-linux-gnu/libmytestlib.so
2026.04.29-14:45:52.60 - <debug> [exec] Symbol: mytestfunc
2026.04.29-14:45:52.60 - <debug> [exec] read[0].size: 4
2026.04.29-14:45:52.60 - <debug> [exec] read[0].type: int32
2026.04.29-14:45:52.60 - <debug> [exec] write[0].size: 4
2026.04.29-14:45:52.60 - <debug> [exec] write[0].type: int32
I got nr_in: 1, nr_out: 1
I got input: 10
Will return output: 20
output1: 20
2026.04.29-14:45:52.60 - <debug> session:1 Looking for func implementing op exec_with_resource
2026.04.29-14:45:52.60 - <debug> Returning func for op exec_with_resource from plugin exec
2026.04.29-14:45:52.60 - <debug> [exec] session:1 Calling exec_with_resource
2026.04.29-14:45:52.60 - <debug> [exec] Number of libraries: 1
2026.04.29-14:45:52.60 - <debug> [exec] Library: /run/user/0/vaccel/WHJlSC/resource.2/lib.so
2026.04.29-14:45:52.60 - <debug> [exec] Symbol: mytestfunc
2026.04.29-14:45:52.60 - <debug> [exec] read[0].size: 4
2026.04.29-14:45:52.60 - <debug> [exec] read[0].type: int32
2026.04.29-14:45:52.60 - <debug> [exec] write[0].size: 4
2026.04.29-14:45:52.60 - <debug> [exec] write[0].type: int32
I got nr_in: 1, nr_out: 1
I got input: 10
Will return output: 20
output2: 20
2026.04.29-14:45:52.60 - <debug> session:1 Unregistered resource 2
2026.04.29-14:45:52.60 - <debug> Removing file /run/user/0/vaccel/WHJlSC/resource.2/lib.so
2026.04.29-14:45:52.60 - <debug> Released resource 2
2026.04.29-14:45:52.60 - <debug> session:1 Unregistered resource 1
2026.04.29-14:45:52.60 - <debug> Released session 1
2026.04.29-14:45:52.60 - <debug> Released resource 1
2026.04.29-14:45:52.60 - <debug> Cleaning up vAccel
2026.04.29-14:45:52.60 - <debug> Cleaning up sessions
2026.04.29-14:45:52.60 - <debug> Cleaning up resources
2026.04.29-14:45:52.60 - <debug> Cleaning up plugins
2026.04.29-14:45:52.60 - <debug> Unregistered plugin exec