From 213afb5cab8f58629144e3be3abe480902cbba00 Mon Sep 17 00:00:00 2001
From: Johanna Bahl <jb@flyingcircus.io>
Date: Tue, 29 Oct 2024 15:19:36 +0100
Subject: [PATCH] Use scriv for changelog management

---
 .pre-commit-config.yaml        |  2 +-
 changelog.d/CHANGELOG.md       |  0
 changelog.d/new_fragment.md.j2 | 17 +++++++++++++++++
 changelog.d/scriv.ini          |  6 ++++++
 changelog.sh                   |  2 +-
 flake.nix                      |  1 +
 release/fc-release.sh          | 23 +++++++++++++++++++++++
 7 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 changelog.d/CHANGELOG.md
 create mode 100644 changelog.d/new_fragment.md.j2
 create mode 100644 changelog.d/scriv.ini
 mode change 100644 => 100755 changelog.sh

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 8872e411c..8b269ef3c 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,4 +1,4 @@
-exclude: ^secrets/|^appenv$|pkgs/fc/sensusyntax/fixtures/(syntaxerror|empty).json|(nixos/infrastructure/container.nix|tests/testlib.nix|nixos/roles/devhost/vm.nix)
+exclude: ^secrets/|^appenv$|pkgs/fc/sensusyntax/fixtures/(syntaxerror|empty).json|(nixos/infrastructure/container.nix|tests/testlib.nix|nixos/roles/devhost/vm.nix)|^changelog.d/new_fragment.md.j2$
 repos:
 - hooks:
   - exclude: "(?x)^(\n  secrets/|environments/.*/secret.*|\n  .*\\.patch\n)$\n"
diff --git a/changelog.d/CHANGELOG.md b/changelog.d/CHANGELOG.md
new file mode 100644
index 000000000..e69de29bb
diff --git a/changelog.d/new_fragment.md.j2 b/changelog.d/new_fragment.md.j2
new file mode 100644
index 000000000..261aea564
--- /dev/null
+++ b/changelog.d/new_fragment.md.j2
@@ -0,0 +1,17 @@
+<!--
+A new scriv changelog fragment.
+
+(Un)comment the section that is right (add/remove the HTML comment wrapper).
+-->
+
+<!--
+### Impact
+
+- A bullet item for the Impact category.
+
+-->
+
+### NixOS platform
+
+- A bullet item for the NixOS platform category.
+
diff --git a/changelog.d/scriv.ini b/changelog.d/scriv.ini
new file mode 100644
index 000000000..dedf2e54f
--- /dev/null
+++ b/changelog.d/scriv.ini
@@ -0,0 +1,6 @@
+[scriv]
+format = md
+entry_title_template =
+categories = Impact, NixOS platform
+output_file = changelog.d/CHANGELOG.md.tmp
+skip_fragments = CHANGELOG.*
diff --git a/changelog.sh b/changelog.sh
old mode 100644
new mode 100755
index fc598241d..f1ad45ff5
--- a/changelog.sh
+++ b/changelog.sh
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-nix develop --impure --command scriv create --edit
+nix develop --impure --command scriv create --edit --add
diff --git a/flake.nix b/flake.nix
index cb5345154..f96f05c27 100644
--- a/flake.nix
+++ b/flake.nix
@@ -139,6 +139,7 @@
 
             packages = with pkgs; [
               jq
+              scriv
             ] ++ (with self'.packages; [
               fcBranchDiffRelease
               fcGetCurrentChannelUrl
diff --git a/release/fc-release.sh b/release/fc-release.sh
index 1e2458689..11131a1cf 100755
--- a/release/fc-release.sh
+++ b/release/fc-release.sh
@@ -18,6 +18,15 @@ if ! git remote -v | grep -Eq "^origin\s.*github.com.flyingcircusio/fc-nixos"; t
     exit 64
 fi
 
+if [[ ! -d ../doc/changelog.d ]] || ! git -C ../doc remote -v | grep -Eq "^origin\s.*github.com.flyingcircusio/doc"; then
+    echo "$0: please ensure that you have a checkout of flyingcircusio/doc next to this repo"
+    exit 64
+fi
+if [[ -e ../doc/changelog.d/"$nixos_version".md ]]; then
+    echo "$0: the changelog fragment '../doc/changelog.d/$nixos_version.md' already exists"
+    exit 64
+fi
+
 git fetch origin --tags --prune
 git checkout "$dev"
 git merge --ff-only  # expected to fail on unclean/unpushed workdirs
@@ -25,8 +34,22 @@ git merge --ff-only  # expected to fail on unclean/unpushed workdirs
 git checkout "$stag"
 git merge --ff-only
 
+TEMP_CHANGELOG=changelog.d/CHANGELOG.md.tmp
+CHANGELOG=changelog.d/CHANGELOG.md
+truncate -s 0 $TEMP_CHANGELOG
+scriv collect --add
+sed -e "s/^## Impact/## Impact\n### $nixos_version/" \
+    -e "s/^## NixOS platform/## NixOS $nixos_version platform/" $TEMP_CHANGELOG > ../doc/changelog.d/"$nixos_version".md
+echo -e "\n" >> $TEMP_CHANGELOG
+cat $CHANGELOG >> $TEMP_CHANGELOG
+(echo "# Release $releaseid"; cat $TEMP_CHANGELOG) > $CHANGELOG
+rm $TEMP_CHANGELOG
+git add $TEMP_CHANGELOG $CHANGELOG
+git commit -m "Collect changelog fragments"
+
 git checkout "$prod"
 git merge --ff-only
+
 msg="Merge branch '$stag' into $prod for release $releaseid"
 git merge -m "$msg" "$stag"