Category: Guides

The nine stages between an application calling sendmail and a person deciding they wanted it — and why every mechanism that judges the message authenticates an address somebody else chose.

The seven stages between a backup and a working machine, and the six decisions the restore makes that the backup did not. Why diff exits 0 on a tree that…

Stage 1: Solved, not run Everyone learns the Dockerfile as a shell script: a list of commands, executed top to bottom, one after another. That model was correct, and both…

Stage 1: What the parent publishes about you A registry holds almost nothing about your domain. Three things, and you can write none of them directly: What the registry actually…

One of this site’s own pages carries a sentence that is true and stops exactly one clause short. It is in Hardening a Public-Facing Service, in the step about updates:…

Six stages, from the member that answered to the restore that hands your data back on a clock that has been wound backwards. Why a successful etcd restore can break…

The six stages between an ACME account and a certificate your server is actually serving, and the two private keys that never meet. Why a renewal that succeeds proves nothing…

You run kubectl apply -f deployment.yaml, wait, and a container is running on a machine you did not choose. Between those two moments sit seven stages, exactly two synchronous calls,…

Eight stages between a client sending COMMIT and data you could still restore a year later. The client waits on exactly one of them. This follows the whole path on…

Two servers is not twice as reliable. It is twice as much to maintain, plus a class of failure that only exists when there are two. Here is how to…