Nexolid

Debugging DNS with dig, step by step

Tue, 03 Nov 2026 08:45:00 +0100

“It’s always DNS” is a joke because it’s usually true. After a migration last week, a customer-facing hostname resolved correctly for half the team and pointed at the old load balancer for the other half. Ten minutes with dig explained it. Here’s the sequence I go through, roughly in order.

Let git find the regression: git bisect run

Wed, 07 Oct 2026 19:15:00 +0200

Last month an integration test started timing out on main. It hadn’t been touched in a year, it passed on the release tag from three weeks earlier, and between the two there were 340 commits from eleven people. Reading the log was hopeless. git bisect run found the culprit in nine steps while I made coffee.

Postgres backups with restic, and actually restoring them

Mon, 14 Sep 2026 09:30:00 +0200

A backup you’ve never restored is a hope, not a backup. I learned that the cheap way, thankfully: during a drill, not an outage. Our nightly job had been writing a perfectly valid, perfectly empty dump for three weeks because pg_dump failed on authentication and the pipe after it didn’t care.

The traps in set -euo pipefail

Mon, 24 Aug 2026 21:40:00 +0200

Almost every bash script I write starts with the same line:

bash

set -euo pipefail

What each flag does:

Small Docker images with multi-stage builds

Sun, 02 Aug 2026 18:05:00 +0200

Image size sounds like a vanity metric until you have forty services, a registry bill and a deploy that spends most of its time pulling layers. Smaller images also mean fewer packages for the security scanner to complain about and a smaller attack surface if something does go wrong.

systemd timers vs cron: why I finally switched

Sun, 12 Jul 2026 10:20:00 +0200

For years my rule was simple: if it runs on a schedule, it goes in cron. One line, everyone can read it, done. Then a nightly job started taking longer than its interval, two copies ran at once, and both wrote to the same file. Nobody noticed for a week because cron mailed the errors to a local mailbox that nobody reads.