buildmaster: Add tool to regenerate repo

* Helpful for architectures and branches without
  haikuporter automating repo generation

buildmaster/backend/assets/bin/update_repo

@@ -0,0 +1,38 @@
+#!/bin/bash
+# Utility to regenerate and resign repository
+# (haikuporter generally does this, however this tool simplifies doing it manually)
+
+BASE_DIR=/var/packages
+REPO_SIGNING_SECRETS="/run/secrets/repo_signing"
+
+if [ $# -ne 2 ]; then
+	echo ""
+	echo "usage: $0 [branch] [architecture]"
+	exit 1;
+fi
+
+if [[ ! -d $BASE_DIR/repository/$1 ]]; then
+	echo "Invalid branch!"
+	exit 1
+fi
+
+if [[ ! -d $BASE_DIR/repository/$1/$2 ]]; then
+	echo "Invalid architecture!"
+	exit 1
+fi
+
+cd $BASE_DIR/repository/$1/$2/current/
+package_repo create repo.info packages/*
+sha256sum repo | awk '{ print $1 }' > repo.sha256
+
+if [ -f $REPO_SIGNING_SECRETS/privatekey ] && [ -f $REPO_SIGNING_SECRETS/privatekeypass ]
+then
+	touch /tmp/haiku-secret.key && chmod 600 /tmp/haiku-secret.key
+	echo "untrusted comment: minisign encrypted secret key" > /tmp/haiku-secret.key
+	cat $REPO_SIGNING_SECRETS/privatekey >> /tmp/haiku-secret.key
+	SIGFLAGS="$SIGFLAGS $(cat $REPO_SIGNING_SECRETS/privatekeypass)"
+	cat $REPO_SIGNING_SECRETS/privatekeypass | minisign -s /tmp/haiku-secret.key -Sm repo
+	rm /tmp/haiku-secret.key
+fi
+
+echo "$BASE_DIR/repository/$1/$2/current repository regenerated!"