apacheKafka: Add update script for per-series version updates

pkgs/servers/apache-kafka/3_9.nix

@@ -1,6 +1,5 @@
 import ./generic.nix {
-  seriesFile = ./3_9.nix;
   kafkaVersion = "3.9.1";
   scalaVersion = "2.13";
-  sha256 = "sha256-3UOZgW5niUbKt2470WhhA1VeabyPKrhobNpxqhW8MaM=";
+  hash = "sha256-3UOZgW5niUbKt2470WhhA1VeabyPKrhobNpxqhW8MaM=";
 }

pkgs/servers/apache-kafka/4_0.nix

@@ -1,6 +1,5 @@
 import ./generic.nix {
-  seriesFile = ./4_0.nix;
   kafkaVersion = "4.0.1";
   scalaVersion = "2.13";
-  sha256 = "sha256-M8xc04WE6w9yYWxMLwX7SINKVvoKnNn+AKxzIMNM9SQ=";
+  hash = "sha256-M8xc04WE6w9yYWxMLwX7SINKVvoKnNn+AKxzIMNM9SQ=";
 }

pkgs/servers/apache-kafka/4_1.nix

@@ -1,6 +1,5 @@
 import ./generic.nix {
-  seriesFile = ./4_1.nix;
   kafkaVersion = "4.1.1";
   scalaVersion = "2.13";
-  sha256 = "sha256-eR6O5plpgtgFWCk2eoA5H5TBvKcymy+7ZYv8IRp3Ry4=";
+  hash = "sha256-eR6O5plpgtgFWCk2eoA5H5TBvKcymy+7ZYv8IRp3Ry4=";
 }

pkgs/servers/apache-kafka/generic.nix

@@ -1,8 +1,7 @@
 {
-  seriesFile,
   kafkaVersion,
   scalaVersion,
-  sha256,
+  hash,
 }:
 
 {
@@ -22,6 +21,7 @@
 let
   jre = jdk17_headless;
   series = lib.replaceStrings [ "." ] [ "_" ] (lib.versions.majorMinor kafkaVersion);
+  seriesFile = ./. + "/${series}.nix";
 in
 stdenv.mkDerivation rec {
   version = "${scalaVersion}-${kafkaVersion}";
@@ -29,7 +29,7 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "mirror://apache/kafka/${kafkaVersion}/kafka_${version}.tgz";
-    inherit sha256;
+    inherit hash;
   };
 
   nativeBuildInputs = [ makeWrapper ];
@@ -69,6 +69,10 @@ stdenv.mkDerivation rec {
   passthru = {
     inherit jre; # Used by the NixOS module to select the supported JRE
     tests.nixos = nixosTests.kafka.base.${"kafka_" + series};
+    updateScript = [
+      ./update.sh
+      seriesFile
+    ];
   };
 
   meta = {

pkgs/servers/apache-kafka/update.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p curl jq nix
+
+set -euo pipefail
+echoerr() { echo "$@" 1>&2; }
+
+fname="$1"
+echoerr "Working on $fname"
+
+# Extract series from filename: 4_1.nix → 4.1
+series=$(basename "$fname" .nix | tr '_' '.')
+echoerr "Series: $series"
+
+# Read current values from the nix file.
+current_kafka_version=$(sed -n 's/.*kafkaVersion = "\(.*\)";/\1/p' "$fname")
+scala_version=$(sed -n 's/.*scalaVersion = "\(.*\)";/\1/p' "$fname")
+echoerr "Current: kafkaVersion=$current_kafka_version scalaVersion=$scala_version"
+
+# Build a regex that matches e.g. "4.1.0", "4.1.1", but not "4.1.0-rc1".
+series_re="^$(echo "$series" | sed 's/\./\\./g')\\.[0-9]+$"
+
+# Fetch tags from the Apache Kafka GitHub repo.
+# Tags are plain semver (no "v" prefix); filter out release candidates.
+latest_version=$(
+  { for page in 1 2 3; do
+      curl -fsSL ${GITHUB_TOKEN:+-u ":${GITHUB_TOKEN}"} \
+        "https://api.github.com/repos/apache/kafka/tags?per_page=100&page=$page"
+    done; } \
+  | jq -r '.[].name' \
+  | grep -E "$series_re" \
+  | sort -V \
+  | tail -1
+)
+
+if [[ -z "$latest_version" ]]; then
+  echoerr "Error: no tags found for series $series"
+  exit 1
+fi
+
+echoerr "Latest version for series $series: $latest_version"
+
+if [[ "$latest_version" == "$current_kafka_version" ]]; then
+  echoerr "Already at latest version $latest_version, nothing to do"
+  exit 0
+fi
+
+# Update kafkaVersion in the nix file.
+sed -i -E "s|(kafkaVersion = \").*(\";)|\1$latest_version\2|" "$fname"
+grep -q "kafkaVersion = \"$latest_version\"" "$fname"
+
+# Compute new SRI hash for the Apache mirror tarball.
+tarball_url="https://archive.apache.org/dist/kafka/${latest_version}/kafka_${scala_version}-${latest_version}.tgz"
+echoerr "Fetching hash for: $tarball_url"
+
+new_hash=$(nix-prefetch-url --type sha256 "$tarball_url" 2>/dev/null)
+if [[ -z "$new_hash" ]]; then
+  echoerr "Error: failed to fetch hash for $tarball_url"
+  exit 1
+fi
+new_hash=$(nix hash convert --hash-algo sha256 --to sri "$new_hash")
+
+echoerr "New hash: $new_hash"
+sed -i -E "s|(hash = \").*(\";)|\1$new_hash\2|" "$fname"
+grep -q "$new_hash" "$fname"
+
+echoerr "Done. Updated $fname from $current_kafka_version to $latest_version"