[new release] mirage (2 packages) (4.5.0)
CHANGES:
- This release introduces a significant change in the Mirage tool by
splitting the definition of command-line arguments used at
configure-time and runtime. Command-line arguments used in the
configure script (also called 'configuration keys' and defined in
the `Key` module) are essential during the setup of module
dependencies for the unikernel, allowing for a specialized
production of a unikernel for a given target runtime environment. On
the other hand, command-line arguments that the unikernel can use at
runtime (defined in the `Runtime_arg` module) are useful for
customizing deployments without altering the dependencies of the
unikernels. (mirage/mirage#1449, mirage/mirage#1450, mirage/mirage#1451, mirage/mirage#1455 @samoht, review by @hannesm)
* API changes:
- There is no more `~stage` parameter for `Key.Arg.info`.
- `Key` now define command-line arguments for the configuration tool.
- There is a new module `Runtime_arg` to define command-line arguments
for the unikernel.
- As there are no more keys type `'Both`, users are now expected to create
two separated keys in that case (one for configure-time, one for runtime)
or decide if the key is useful at runtime of configure-time.
* Intended use of configuration keys (values of type `'a key`):
- Used to set up module dependencies of the unikernel, such as the
target (hvt, xen, etc.) and whether to use DHCP or a fixed IP address.
- Enable the production of specialized unikernels suitable for
specific target runtime environments and dedicated network and
storage stacks.
- Similar keys will produce reproducible binaries to be uploaded to artifact
repositories like Docker Hub or https://builds.robur.coop/.
* Intended use of command-line runtime arguments (values of type
`a runtime_arg`):
- Allow users to customize deployments by changing device
configuration, like IP addresses, secrets, block device names,
etc., post downloading of binaries.
- These keys don’t alter the dependencies of the unikernels.
- A runtime keys is just a reference to a normal Cmdliner term.
* `key_gen.ml` is not generated anymore, so users cannot refer to
`Key_gen.<key_name>` directy.
- Any runtime argument has to be declared (using `runtime_arg` and
registered on the device (using `~runtime_args`). The value of that
argument will then be passed as an extra parameter of the `connect`
function of that device.
- Configuration keys are not available at runtime anymore. For
instance, `Key_gen.target` has been removed.
* Code migration:
```ocaml
(* in config.ml *)
let key =
let doc = Key.Arg.info ~doc:"A Key." ~stage:`Run [ "key" ] in
Key.(create "key" Arg.(opt_all ~stage:`Run string doc))
```
becomes:
```ocaml
(* in unikernel.ml *)
open Cmdliner
let key =
let doc = Arg.info ~doc:"A Key." [ "key" ] in
Arg.(value & opt_all string [] doc)
```
```ocaml
(* in unikernel.ml *)
let start _ =
let key = Key_gen.hello () in
...
```
becomes:
```ocaml
(* in config.ml *)
let hello = runtime_arg ~pos:__POS__ "Unikernel.hello"
let main = main ~runtime_args:[hello] ...
```
```
(* in unikernel.ml *)
let hello =
let open Cmdliner in
let doc = Arg.info ~doc:"How to say hello." [ "hello" ] in
Arg.(value & opt string "Hello World!" doc)
let start _ hello =
...
```
- bump minimal ocaml-solo5 version bound to 0.8.2 to avoid fast memory usage
error (mirage/mirage#1507, @palainp)
- BREAKING: the packages `functoria` and `functoria-runtime` are removed. The
respectives libraries became `mirage.functoria` and `mirage-runtime.functoria`
(mirage/mirage#1509, @samoht)
- BREAKING: `Mirage.keys` is renamed to `Mirage.runtime_args` (mirage/mirage#1506, @samoht)
- BREAKING: remove `Mirage.foreign. Use `Mirage.main` instead (mirage/mirage#1505, @samoht)
- BREAKING: `Mirage.main` does not take a `?extra_deps` parameter anymore
(mirage/mirage#1505, @samoht)
- BREAKING: the `Mirage.connect` functions passed to create devices
(with `Mirage.impl`) now take values of type `'a Mirage.code` instead
of `string`. Value of type `code` are created using a new `Mirage.code`
function, that takes `~pos:__POS__` as parameter. This is used to generate
better locations in the generated code, leading to better error messages
(mirage/mirage#1504, @samoht)
- BUGFIX: fix `mirage describe` output (mirage/mirage#1446 @samoht), add test (mirage/mirage#1458 @samoht)
- Remove ipaddr from runtime (mirage/mirage#1437 @samoht, mirage/mirage#1465 @hannesm)
- BREAKING: `Mirage.register` no longer have `?packages` and `?keys` arguments
(mirage/mirage#1433, mirage/mirage#1434 @hannesm)
- BREAKING: Remove deprecated bindings and types (mirage/mirage#1461 @hannesm)
- BREAKING: Remove `mirage build` subcommand, use `dune build` in Makefile
(mirage/mirage#1404 @hannesm), put `--profile release` in Makefile instead of
dune-workspace (mirage/mirage#1470 @hannesm)
- Increase dune version to 2.9 in generated dune-project (mirage/mirage#1443 @samoht)
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