Merge #4307

4307: Implement the Consensus release process r=Jasagredo a=Jasagredo

# Description

Implement the Release process as agreed by the Consensus team. See [the ReleaseProcess document](./ouroboros-consensus/docs/ReleaseProcess.md) for more information.

In particular, this creates:
- symlinks for each folder into their appropriate `changelog.d` directory
- two main CHANGELOG.md files, in `ouroboros-consensus` and `ouroboros-consensus-cardano`
- updates the version number in some ledger-agnostic packages that were behind
- configures `scriv` and provides a fork that understands the bare minimum of colon separated files, in particular of `.cabal` files.
- updates the PR template
- Provides a top level changelog that points to the others

Closes #4306 



Co-authored-by: Javier Sagredo <jasataco@gmail.com>
Co-authored-by: Alexander Esgen <alexander.esgen@iohk.io>
Co-authored-by: Javier Sagredo <javier.sagredo@iohk.io>

Author: 3 people

.github/PULL_REQUEST_TEMPLATE.md

@@ -22,7 +22,11 @@ the PR to a particular issue, see
     - [ ] Commits have useful messages
     - [ ] The documentation has been properly updated
     - [ ] New tests are added if needed and existing tests are updated
-    - [ ] If this branch changes Consensus and has any consequences for downstream repositories or end users, said changes must be documented in [`interface-CHANGELOG.md`](../ouroboros-consensus/docs/interface-CHANGELOG.md)
+    - [ ] Any changes affecting Consensus packages must have an entry in the
+          appropriate `changelog.d` directory created using
+          [`scriv`](https://github.com/input-output-hk/scriv). If in doubt, see
+          the [Consensus release
+          process](../ouroboros-consensus/docs/ReleaseProcess.md).
     - [ ] If this branch changes Network and has any consequences for downstream repositories or end users, said changes must be documented in [`interface-CHANGELOG.md`](../docs/interface-CHANGELOG.md)
     - [ ] If serialization changes, user-facing consequences (e.g. replay from genesis) are confirmed to be intentional.
 - Pull Request

Consensus-CHANGELOG.md

@@ -0,0 +1,22 @@
+# Consensus Changelog
+
+The Consensus packages are organized in two bundles: the packages that are
+ledger-agnostic and the packages that are Cardano specific. For each of these
+bundles we keep a separate `CHANGELOG.md` file, and the version number of all
+the packages in each bundle moves in lockstep. We use symlinks to unify the
+`changelog.d` directory in each of the bundles.
+
+The two Changelogs can be found here:
+- [ledger-agnostic bundle](./ouroboros-consensus/CHANGELOG.md)
+- [Cardano-specific bundle](./ouroboros-consensus-cardano/CHANGELOG.md)
+
+If you have any doubts, please consult the [release
+process](./ouroboros-consensus/docs/ReleaseProcess.md).
+
+In short:
+- To create a new changelog entry, navigate to the root of the package you want
+  to create an entry for and run `scriv create`. This will create a template
+  file in `./changelog.d` which you have to edit with the information of your
+  entry.
+- When doing a release, `scriv collect` collects all the pending changelog
+  entries and put them in the `CHANGELOG.md` file.

nix/pkgs.nix

@@ -31,5 +31,7 @@ with pkgs; {
     inherit (ouroborosNetworkHaskellPackages) index-state;
   }).stylish-haskell.components.exes.stylish-haskell;
 
+  scriv = pkgs.callPackage ./scriv.nix { };
+
   trace = builtins.trace;
 }

nix/scriv.nix

@@ -0,0 +1,25 @@
+# TODO remove once https://github.com/NixOS/nixpkgs/pull/212603 is in our nixpkgs pin
+
+{ lib, python3, fetchFromGitHub }:
+
+python3.pkgs.buildPythonApplication {
+  pname = "scriv";
+  version = "1.2.0-custom-iog";
+
+  src = fetchFromGitHub {
+    owner = "input-output-hk";
+    repo = "scriv";
+    rev = "567a1aa3f6df77d1a531290f10a261ec6a49c75a";
+    hash = "sha256-wpWDuZ3c8JJKVWPw9PHgcpneRWYjd/0z4oAIirPa0/E=";
+  };
+
+  propagatedBuildInputs = [
+    python3.pkgs.attrs
+    python3.pkgs.click
+    python3.pkgs.click-log
+    python3.pkgs.jinja2
+    python3.pkgs.requests
+  ] ++ lib.optionals (python3.pythonOlder "3.11") [ python3.pkgs.tomli ];
+
+  doCheck = false;
+}

ouroboros-consensus-byron-test/CHANGELOG.md

@@ -0,0 +1,6 @@
+# CHANGELOG
+
+This package is part of a bundle of packages. Please consult `CHANGELOG.md` in
+the package `ouroboros-consensus-cardano` at the same version as this package to
+see the current changelog that applies also to this package.
+

ouroboros-consensus-byron-test/changelog.d

@@ -0,0 +1 @@
+../ouroboros-consensus-cardano/changelog.d

ouroboros-consensus-byron-test/ouroboros-consensus-byron-test.cabal

@@ -12,6 +12,7 @@ author:                 IOHK Engineering Team
 maintainer:             operations@iohk.io
 category:               Network
 build-type:             Simple
+extra-source-files:     CHANGELOG.md
 
 source-repository head
   type:     git

ouroboros-consensus-byron/CHANGELOG.md

@@ -0,0 +1,5 @@
+# CHANGELOG
+
+This package is part of a bundle of packages. Please consult `CHANGELOG.md` in
+the package `ouroboros-consensus-cardano` at the same version as this package to
+see the current changelog that applies also to this package.

ouroboros-consensus-byron/changelog.d

@@ -0,0 +1 @@
+../ouroboros-consensus-cardano/changelog.d

ouroboros-consensus-byron/ouroboros-consensus-byron.cabal

@@ -12,6 +12,7 @@ author:                 IOHK Engineering Team
 maintainer:             operations@iohk.io
 category:               Network
 build-type:             Simple
+extra-source-files:     CHANGELOG.md
 
 source-repository head
   type:     git