Docker's default logging driver writes container output to a JSON file with no size limit and no rotation. This is a practical guide to Docker log rotation: what the defaults actually do, why your daemon.json change did nothing, why deleting the log file did not free any disk, and how to choose between json-file, local, journald and shipping logs off the box.
The dashboard is fine for editing a post. It is a terrible tool for anything touching a thousand rows, twelve plugins or two servers. Here are the WP-CLI commands that save hours on migrations, plugin conflicts, stalled cron and integrity checks, grouped by the job that eats the time, with the failure modes each one hides.
On a stock Linux server, journald and rsyslog are both running and both storing the same events, with retention policies that don't know about each other. Here's where each log line actually lives, the three failure modes that bite in production, and how to decide which copy you keep.
You set PasswordAuthentication no, restarted SSH, and moved on. Months later the logs show successful password logins, because a vendor drop-in file sorted earlier and won. A VPS setup and hardening checklist where every step comes with the command that proves it worked.
Your browser shows a padlock and your partner's API client throws "unable to get local issuer certificate". Both are correct. A practical guide to the four things a TLS client actually checks, and to renewal automation that reaches the running server instead of just the disk.
Loki was fast until someone added one more label. Now queries time out during incidents and the index no longer fits in memory. Here's the model you have to internalise, what replaced Promtail, and how to keep labels, retention and storage costs under control.
Metrics tell you that something is wrong. Traces tell you where. Logs tell you why. Use them in that order and each step narrows the search — start with logs and you are grepping a firehose. Here is what each one is actually for, and the field that connects all three.
The top search result tells you to run docker system prune -a --volumes. It frees the space and deletes your database. Here is how to measure Docker disk usage properly, reclaim it from safest to most destructive, and fix the logs that Docker never reports on.
Two static binaries, a package and four systemd units. How to install Prometheus and Grafana on a single server from scratch, wire in node_exporter, put nginx and TLS in front, and keep the ports that have no authentication off the public internet.
Almost every TLS certificate error traces back to one of three causes: a broken chain, a hostname the certificate does not cover, or an expiry nobody was watching. Here is how to tell them apart in under a minute, and how to stop the third one from ever happening again.