Upgrading rocketchat to version 5.0 resulted in some minor issues that prevented the system from starting - both are related to the database and can easily be fixed.
Upgrading postgres can be a challenging task, because databases are mostly in use. Having extensions like timescaledb introduces even more complexity. This guide shows a fast way to upgrade a postgres database with timescaledb.
This series covers migrating a zabbix database from mysql to timescaledb. In this post we're preparing the databases for the migration.
Running services in docker swarm utilizes the docker swarm routing mesh which results in source nat (snat). If you need to bypass this, check out this guide.
Having upgraded docker you may come into a situation where the docker daemon itself doesn't start anymore because of an issue with firewalld.
Containers are no virtual machines - yet we might want to treat hosts running container workloads like hypervisors and apply limitations on container networking. This guide describes a way to limit container networking on docker based container hosts using firewalld.