From 6510f269f6a4655e69d4d59e012462dca066a65a Mon Sep 17 00:00:00 2001
From: Erik Arvstedt <erik.arvstedt@gmail.com>
Date: Sat, 8 Jul 2023 15:33:09 +0200
Subject: [PATCH] release: add `nixos-*` version branch

Best practice for flakes containing NixOS modules.

`push-release` now pushes to an extra branch named `nixos-<version>`,
alongside branch `release`.
This allows users to track a specific NixOS release, so that their
config doesn't break when nix-bitcoin switches to a new NixOS
release.
---
 examples/flakes/flake.nix |  2 ++
 helper/push-release.sh    | 14 +++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/examples/flakes/flake.nix b/examples/flakes/flake.nix
index 4b23845..31216d3 100644
--- a/examples/flakes/flake.nix
+++ b/examples/flakes/flake.nix
@@ -2,6 +2,8 @@
   description = "A basic nix-bitcoin node";
 
   inputs.nix-bitcoin.url = "github:fort-nix/nix-bitcoin/release";
+  # You can also use a version branch to track a specific NixOS release
+  # inputs.nix-bitcoin.url = "github:fort-nix/nix-bitcoin/nixos-23.05";
 
   outputs = { self, nix-bitcoin }: {
 
diff --git a/helper/push-release.sh b/helper/push-release.sh
index 56e02e0..38dde9c 100755
--- a/helper/push-release.sh
+++ b/helper/push-release.sh
@@ -53,6 +53,13 @@ if [[ ! $DRY_RUN ]]; then
    done
 fi
 
+nixosVersion=$(sed -nE 's|.*system.stateVersion = "(.*?)".*|\1|p' ../examples/configuration.nix)
+if [[ ! $nixosVersion ]]; then
+    echo "Error fetching NixOS version"
+    exit 1
+fi
+nixosVersionBranch=nixos-$nixosVersion
+
 TMPDIR=$(mktemp -d)
 if [[ ! $DRY_RUN ]]; then trap 'rm -rf $TMPDIR' EXIT; fi
 ARCHIVE_NAME=nix-bitcoin-$releaseVersion.tar.gz
@@ -74,9 +81,13 @@ gpg -o nar-hash.txt.asc -a --detach-sig nar-hash.txt
 
 if [[ $DRY_RUN ]]; then
     echo "Created v$releaseVersion in $TMPDIR"
+    echo "NixOS version branch: $nixosVersionBranch"
     exit 0
 fi
 
+#―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
+# Create release
+
 POST_DATA="{ \"tag_name\": \"v$releaseVersion\", \"name\": \"nix-bitcoin-$releaseVersion\", \"body\": \"nix-bitcoin-$releaseVersion\", \"target_comitish\": \"$BRANCH\" }"
 RESPONSE=$(curl -fsS -H "Authorization: token $OAUTH_TOKEN" -d "$POST_DATA" https://api.github.com/repos/$REPO/releases)
 ID=$(echo "$RESPONSE" | jq -r '.id')
@@ -101,7 +112,8 @@ post_asset "$SHA256SUMS.asc"
 popd >/dev/null
 
 if [[ ! $DRY_RUN ]]; then
-    git push "$GIT_REMOTE" "${BRANCH}:release"
+    git push "$GIT_REMOTE" "$BRANCH:release"
+    git push "$GIT_REMOTE" "$BRANCH:$nixosVersionBranch"
 fi
 
 echo "Successfully created" "$(echo "$POST_DATA" | jq -r .tag_name)"