docker – Page 10 – Türker Yıldırım

A healthcheck that tests the app, not the port

NoteJune 15, 20212 min read

A health check that opens a TCP connection reports healthy for a process that is listening and cannot serve a request. The rule that has held up is…

BuildKit cache mounts for composer and npm

NoteJune 8, 20212 min read

A layer cache is invalidated by a lock file change; a cache mount survives it, because the downloaded packages are not in the layer at all. The syntax…

Terraform 1.0 is a promise about the next five years

Deep diveJune 2, 202110 min read

A version number that is a compatibility statement rather than a feature list. Three environments described by hand, and the import that is most of the work.

Two hundred integration tests that share one database

Deep diveMay 27, 202110 min read

A suite that passes alone and fails in a different order. Test 141 depends on a row test 88 created, and nobody wrote that down.

Compose v2 is a plugin, and the hyphen finally goes

Deep diveMay 19, 20219 min read

The same command, spelled two ways, on eight machines. A Python program became a Go plugin, and the container names changed underneath every script.

The dotnet service that finally moved behind the same gateway

Deep diveApril 27, 202110 min read

One service in a different language, with its own auth, its own log format and its own deploy. The language was the least interesting difference.

A named volume that outlives the compose file

NoteApril 16, 20212 min read

docker compose down removes containers and networks and leaves named volumes, which is the safe default and the reason a database survives a version change you did not…

A secret mount is not an ARG, and history proves it

NoteApril 16, 20212 min read

A build argument is recorded in the image history whether or not the build used it, so a token passed as an ARG is readable by anybody who…

Wait for a compose service to be healthy before running tests

SnippetApril 12, 20211 min read

The staging environment that was lying

Deep diveApril 8, 202110 min read

It passed on staging four times and failed in production four times. The same code, a different outcome, and five differences nobody had enumerated.