Import alt-mysql plugin

scripts/setup/alt_mysql_health_check.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck source=./mysql_common.sh
+source "$SCRIPT_DIR/mysql_common.sh"
+
+fail() {
+  echo "alt-mysql health: $*" >&2
+  exit 1
+}
+
+mysql_load_alt_runtime
+mysql_load_alt_credentials
+
+if command -v systemctl >/dev/null 2>&1; then
+  systemctl is-active --quiet "$MYSQL_ALT_SERVICE_NAME" || fail "service is not active: $MYSQL_ALT_SERVICE_NAME"
+fi
+
+[ -r "$MYSQL_ALT_MY_CNF" ] || fail "client defaults file is not readable: $MYSQL_ALT_MY_CNF"
+[ -r "$MYSQL_ALT_MYSQL_CONF" ] || fail "credentials file is not readable: $MYSQL_ALT_MYSQL_CONF"
+[ -n "$MYSQL_ALT_PORT" ] || fail "alt port was not discovered"
+[ -n "$MYSQL_ALT_SOCKET" ] || fail "alt socket was not discovered"
+
+"$(mysql_alt_binary mysql)" --defaults-extra-file="$MYSQL_ALT_MY_CNF" -e "SELECT 1" >/dev/null \
+  || fail "cannot connect through $MYSQL_ALT_MY_CNF"
+
+mysql_ensure_metadata_schema
+mysql_exec mysql -e "SELECT COUNT(*) FROM da_plugin_database_owners" >/dev/null \
+  || fail "metadata schema is not usable"
+
+echo "alt-mysql health: OK"