#IS X MIRAGE SAFE CODE#

In Mirage 3.0.0, we've tried to replace the calls to Console.log with calls to bug,, or Logs.warn as appropriate. The mirage_logs library and its incorporation into the configuration language dates back to version 2.9.0, but a number of libraries still required a console impl argument and expected to log to the console. This leads us to another big change that predates MirageOS 3, but is more widely used and better supported in this release: logging.

You may notice that generic_stackv4 doesn't take a console argument, where the previous direct_stackv4* and socket_stackv4 functions did. With this: let stack = generic_stackv4 default_network | `Direct, `Static -> direct_stackv4_with_default_ipv4 console tap0 | `Direct, `Dhcp -> direct_stackv4_with_dhcp console tap0

#IS X MIRAGE SAFE CODE#

We can replace this old code from config.ml: let net = Porting the stackv4 example to Mirage 3ДЄ good example of replacing old configurator code can be seen between the pre-functoria network example, and the device-usage/network example from the Mirage-3.0.0-compatible branch of mirage-skeleton. Many existing unikernels will find it useful to replace their existing network stack detecting code with generic_stackv4 in particular - let's see an example. Val default_argv: Functoria_app.argv impl Several useful default_ and generic_ functions are provided by the Mirage module for use in config.ml: ~/mirage$ grep -E 'val (generic_|default_)' lib/mirage.mli The command-line argument -kv_ro will be understood when mirage configure is run from a directory with a config.ml including generic_kv_ro. Generic_kv_ro knows about not only the Xen, Unix, and MacOSX targets handled by the previous config.ml code, but also will do the right thing for new targets Ukvm, Virtio, and Qubes. The code above can be replaced with: let disk = generic_kv_ro 't' | `Crunch, (`Unix | `MacOSX) -> direct_kv_ro 't'ДЇunctoria improved the situation considerably by including convenience functions which not only have logic for autodetecting which implementations are suitable based on the backend selected, but also other arguments given to mirage configure. | x -> failwith ('Unknown FS mode: ' ^ x ) Let x = try Unix.getenv 'FS' with Not_found -> 'crunch' in

Numerous older config.ml files include code like the following, from mirage-skeleton's kv_ro example in commit 21adfc85b124e886d871079f28bd0a868ba3c5fb, which attempts to detect which kv_ro device to use based on the target chosen with mirage configure -t and environment variables: let mode = The idiom for deciding which impl to use based on the backend is the most noticeable change. Many users whose unikernels predate Mirage 2.7.0 will first notice the functoria improvements in the 3.0.0 release, as they'll finally be forced to use them. It was still possible to use the previous calls, however, until Mirage 3.0.0 where support for them was dropped. config.ml and generic/default functionsДЄ number of refinements to the configuration language for Mirage were made in the Mirage 2.7.0 release, which incorporated the functoria DSL. If your unikernel was based on one of the examples in the mirage-skeleton repository, you may find hannesm's collection of diffs from v2.9.1 to v3.0.0 for popular unikernels to be a useful reference. This document is a guide to porting your existing unikernel from the Mirage 2.x interface to Mirage 3.x.

Porting Mirage 2.x Projects to Mirage 3.x IncompatibilitiesДЇor a short summary of breaking changes, see the Mirage 3.0.0 release notes.

Is x mirage safe