package functoria

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A DSL to organize functor applications


Dune Dependency






Functoria is a DSL to describe a set of modules and functors, their types and how to apply them in order to produce a complete application.

The main use case is mirage. See the mirage repository for details.



Published: 15 Feb 2024


MirageOS logo
Build Unikernels in OCaml

MirageOS is a library operating system that constructs secure, performant and resource-efficient unikernels.


MirageOS is a library operating system that constructs unikernels for secure, high-performance network applications across various cloud computing and mobile platforms. Developers can write code on a traditional OS such as Linux or macOS. They can then compile their code into a fully-standalone, specialised unikernel that runs under the Xen or KVM hypervisors and lightweight hypervisors like FreeBSD's BHyve, OpenBSD's VMM. These unikernels can deploy on public clouds, like Amazon's Elastic Compute Cloud and Google Compute Engine, or private deployments.

The most up-to-date documentation can be found at the homepage. The site is a self-hosted unikernel. Simpler skeleton applications are also available online. MirageOS unikernels repositories are also available here or there.

This repository

This repository contains the mirage command-line tool to create and deploy applications with MirageOS. This tool wraps the specialised configuration and build steps required to build MirageOS on all the supported targets.

Local install

You will need the following:

  • a working OCaml compiler (4.08.0 or higher).

  • the Opam source package manager (2.1.0 or higher).

  • an x86_64 or armel Linux host to compile Xen kernels, or FreeBSD, OpenBSD or MacOS X for the solo5 and userlevel versions.

Then run:

$ opam install mirage
$ mirage --version

This should display at least version 4.0.0.

Using mirage

There are multiple stages to using mirage:

  • write to describe the components of your applications;

  • call mirage configure to generate the necessary code and metadata;

  • optionally call make depends to install external dependencies and download Opam packages in the current dune workspace.

  • call dune build to build a unikernel.

You can find documentation, walkthroughs and tutorials over on the MirageOS website. The install instructions are a good place to begin!

Dependencies (13)

  1. uri >= "4.2.0"
  2. emile >= "1.1"
  3. fpath
  4. bos
  5. logs
  6. fmt >= "0.8.7"
  7. astring
  8. result >= "1.5"
  9. rresult >= "0.7.0"
  10. cmdliner >= "1.1.1"
  11. base-unix
  12. dune >= "2.9.0"
  13. ocaml >= "4.08.0"

Dev Dependencies (5)

  1. bigstringaf with-test & >= "0.5.0"
  2. functoria-runtime = version & with-test
  3. alcotest with-test
  4. cmdliner with-test & >= "1.2.0" & < "1.3.0"
  5. dune with-test & >= "3.0.0"

Used by (1)

  1. mirage = "4.4.2"




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