Docker

w is a very helpful command-line tool for a quick overview of which users are currently logged in and what they are doing.

Docker is wasteful with IP subnets by default. On hosts with many networks, this sooner or later leads to the following error: Error response from daemon: could not find an …

While reviewing logs from various Docker containers I ran into an issue: some containers were running with the host's local timezone (CET), others with UTC. While debugging I even …