This package contains a number of libraries and utilities that can be used to easily start CloudABI programs.
The libcloudabi
library provides a native port of the program_exec()
function. This is the function that can normally be used by CloudABI
programs to start new executables, similar to the POSIX fexecve()
function.
Whereas fexecve()
uses simple string command line arguments,
program_exec()
uses a YAML-like tree structure, called
argdata
. What is special about
argdata
, is that file descriptors are a native primitive data type;
they can be attached as leaves to the tree directly. This makes the way
of inheriting file descriptors during process execution a lot more
structured. It replaces concepts like close-on-exec flags entirely.
To ensure that this implementation of program_exec()
conforms to
CloudABI's safety requirements (i.e., that it is safe to run untrusted
programs, and that file descriptors that are not referenced by the
argdata
structure are not leaked into new processes),
program_exec()
depends on a small proxy executable called
cloudabi-reexec
. This package ships with prebuilt copies that were
built by the
CloudABI Ports Collection.
Finally, this package provides the cloudabi-run
utility, which is
built on top of libcloudabi
. This utility reads a YAML file from
stdin
, converts it to an argdata
, and uses that to start a CloudABI
executable. It provides some special tags to automatically open files
and network connections. cloudabi-run
also includes an emulator that
can be used to run CloudABI executables on operating systems for which
no native support is provided. Please refer to cloudabi-run
's manual
page for more details and examples.
More details about CloudABI can be found on Nuxi's company webpage.