linux – Page 5 – Türker Yıldırım

A maintenance page that was actually served

NoteMarch 15, 20232 min read

A maintenance page that requires the application to be running is not a maintenance page. Serving it from the web server means it works when PHP is stopped,…

A base image we build ourselves, and the CVE report that paid for it

Deep diveMarch 15, 202310 min read

A scanner reporting 41 vulnerabilities, 39 of them in packages we do not use. A weekly report that has never once been actionable.

An ssh config that made a runbook one word long

NoteMarch 10, 20232 min read

A runbook step that read “ssh to the app server, jumping through the bastion, as the deploy user, with the right key” is a config entry, not an…

monit on a box that already has systemd

NoteFebruary 28, 20231 min read

Two supervisors watching the same process, each willing to restart it, and one of them unaware of the other. monit predates systemd on most of these hosts and…

Unattended upgrades with a reboot at 04:00

NoteFebruary 21, 20231 min read

Automatic security updates with automatic reboots, on a host that runs queue workers with no drain step. The reboot is right and the missing piece is a systemd…

The Dockerfile that finally stopped installing the world

Deep diveJanuary 25, 20238 min read

A 1.4 GB image and a six-minute build, for an application that is 40 MB of PHP. Most of it is build tooling that shipped by accident.

Blue-green on one host, which is two directories

NoteJanuary 24, 20232 min read

The pattern does not require two machines, a load balancer or an orchestrator — it requires two copies and a pointer. mv -T on a symlink is atomic…

A systemd restart policy that hid a crash loop

NoteJanuary 18, 20232 min read

A worker that had been restarting every 40 seconds for eleven days, reported as active by every check that looked. Restart=always with no burst limit converts a hard…

The container that ran as root because of one chown

NoteJanuary 2, 20232 min read

A Dockerfile that switched to a non-root user, then switched back for one directory permission and never switched forward again. The line that switched to root was correct…

Larger runners, and the pipeline that was memory-bound

Deep diveDecember 13, 202210 min read

October, larger runners, and a build that was swapping. A Node build that used 6 GB on a 7 GB runner.