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Mirage Compilation Process

This document details the details of the compilation process for MirageOS unikernels. It outlines the steps required to prepare, compile, and manage dependencies for Mirage applications.

Overview of the Compilation Process

Developing a simple application with Mirage involves starting with two primary files:

• config.ml: Contains the configuration of your unikernel.

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A distributed, decentralized immutable block store for dune-cache

Objective

The aim of this project is to create a system to store data in the form of immutable, content addressable blocks that can be used as a backend for the dune-cache-daemon.

The envisioned characteristics are:

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open Mirage

let disk = generic_kv_ro "t"

let main = foreign "Unikernel.Main" (kv_ro @-> job)

let () = register ~reporter:Mirage.no_reporter "kv_ro" [ main $ disk ]

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# Solver: builtin-mccs+glpk
# Criteria: -removed,-count[version-lag,request],-count[version-lag,changed],-changed
preamble: 
property: opam-query: int = [0], version-lag: nat = [0], pinned: bool = [false], installed-root: bool = [false], reinstall: bool = [false], opam-version: string, opam-name: string

package: fstar
version: 3
depends: ocaml >= 34 , ocamlfind , batteries , ocamlbuild , num
conflicts: fstar
version-lag: 5

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 unexpected fault address 0x420580
fatal error: fault
[signal 0xb code=0x2 addr=0x420580 pc=0x7663ff]

goroutine 156126 [running]:
runtime.throw(0x1e1c070, 0x5)
	/usr/local/go/src/runtime/panic.go:547 +0x90 fp=0xc82222fd58 sp=0xc82222fd40
runtime.sigpanic()
	/usr/local/go/src/runtime/sigpanic_unix.go:27 +0x2ab fp=0xc82222fda8 sp=0xc82222fd58
encoding/json.(*decodeState).scanWhile(0x420568, 0x9, 0xc822372168)

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Bundles

OPAM can manage development and deployment bundles

Commands

Now that we have compiler-as-packages, switches can come empty by default. OPAM 2.0 adds a new mechanism to handle set of packages, called bundles.

Switch bundle

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Managing local packages

OPAM is able to manage local packages.

Commands

The opam package sub-command extracts and uses the fields of a local opam file as it is was a globally available package.

Documentation

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#!/usr/bin/env bash

# Instructions. You need:
# - a working opam environment
# - an opam file in your current directory (to describe your project)
# - possibly some packages path-pinned in the current switch
#
# Run the scripts, and then check the contents of sources/

set -eu

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module type S1 = sig
  type t
end

module X = struct
  type t = int
  let f x = x
end

module type S2 = sig

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(* Run that file at the root of your repository:

      ocamlbuild -pkg opam chek_ocamlfind.native --
  
  This will rewrite all the OPAM files to add the missing ocamlfind dependency if needed.
*)

open OpamTypes
module N = OpamPackage.Name