prometheus: Add update.sh script

pkgs/by-name/pr/prometheus/package.nix

@@ -186,12 +186,16 @@ buildGoModule (finalAttrs: {
     "-skip=TestEvaluations/testdata/aggregators.test"
   ];
 
-  passthru.tests = { inherit (nixosTests) prometheus; };
+  passthru = {
+    tests = { inherit (nixosTests) prometheus; };
+    updateScript = ./update.sh;
+  };
 
   meta = {
     description = "Service monitoring system and time series database";
     homepage = "https://prometheus.io";
     license = lib.licenses.asl20;
+    changelog = "https://github.com/prometheus/prometheus/blob/v${version}/CHANGELOG.md";
     maintainers = with lib.maintainers; [
       fpletz
       Frostman

pkgs/by-name/pr/prometheus/update.sh

@@ -0,0 +1,77 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p nix coreutils curl jq nix-prefetch-git prefetch-npm-deps
+
+set -euo pipefail
+
+OWNER=prometheus
+REPO=prometheus
+
+# Current version.
+LATEST_NIXPKGS_VERSION=$(nix eval --raw .#prometheus.version 2>/dev/null)
+UPDATE_NIX_OLD_VERSION=${UPDATE_NIX_OLD_VERSION:-$LATEST_NIXPKGS_VERSION}
+
+TARGET_TAG="$(curl -L -s ${GITHUB_TOKEN:+-u ":${GITHUB_TOKEN}"} "https://api.github.com/repos/$OWNER/$REPO/releases/latest" | jq -r '.tag_name')"
+TARGET_VERSION="$(echo "$TARGET_TAG" | sed -e 's/^v//')"
+
+if [[ "$UPDATE_NIX_OLD_VERSION" == "$TARGET_VERSION" ]]; then
+    # prometheus is up-to-date
+    if [[ -n "$UPDATE_NIX_ATTR_PATH" ]]; then
+        echo "[{}]";
+    fi
+
+    exit 0
+fi
+
+extractVendorHash() {
+    original="${1?original hash missing}"
+    result="$(nix-build -A prometheus.goModules 2>&1 | tail -n3 | grep 'got:' | cut -d: -f2- | xargs echo || true)"
+    [ -z "$result" ] && { echo "$original"; } || { echo "$result"; }
+}
+
+TMP=$(mktemp -d)
+trap 'rm -rf "$TMP"' EXIT
+
+NIXPKGS_PROMETHEUS_PATH=$(cd $(dirname ${BASH_SOURCE[0]}); pwd -P)/
+SOURCE_NIX="$NIXPKGS_PROMETHEUS_PATH/source.nix"
+
+PREFETCH_JSON=$TMP/prefetch.json
+nix-prefetch-git --rev "$TARGET_TAG" --url "https://github.com/$OWNER/$REPO" > "$PREFETCH_JSON"
+PREFETCH_HASH="$(jq '.hash' -r < "$PREFETCH_JSON")"
+PREFETCH_PATH="$(jq '.path' -r < "$PREFETCH_JSON")"
+NPM_DEPS_HASH="$(prefetch-npm-deps "$PREFETCH_PATH/web/ui/package-lock.json")"
+
+FAKE_HASH="sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
+
+cat > "$SOURCE_NIX" <<-EOF
+{
+  version = "$TARGET_VERSION";
+  hash = "$PREFETCH_HASH";
+  npmDepsHash = "$NPM_DEPS_HASH";
+  vendorHash = "$FAKE_HASH";
+}
+EOF
+
+GO_HASH="$(nix-instantiate --eval -A prometheus.vendorHash | tr -d '"')"
+VENDOR_HASH=$(extractVendorHash "$GO_HASH")
+
+cat > "$SOURCE_NIX" <<-EOF
+{
+  version = "$TARGET_VERSION";
+  hash = "$PREFETCH_HASH";
+  npmDepsHash = "$NPM_DEPS_HASH";
+  vendorHash = "$VENDOR_HASH";
+}
+EOF
+
+if [[ -z "$UPDATE_NIX_ATTR_PATH" ]]; then
+    exit 0
+fi
+
+cat <<-EOF
+[{
+  "attrPath": "$UPDATE_NIX_ATTR_PATH",
+  "oldVersion": "$UPDATE_NIX_OLD_VERSION",
+  "newVersion": "$TARGET_VERSION",
+  "files": ["$SOURCE_NIX"]
+}]
+EOF