Three Test Jails on a 512 MB Free-Tier VPS

Table of Contents Table of Contents The Box Why pkgbase Makes Test Jails Cheap Sharp edge one: the fingerprints live inside the rootdir Sharp edge two: nobody runs ldconfig for you The Smallest jail.conf That Does Anything Three Jails, Three Code Paths The gotcha that will bite anyone running Ansible against a jail Does the Test Actually Catch the Bug? What It Cost Takeaways Someone opened an issue against ansible-jailexec, the Ansible connection plugin for FreeBSD jails I wrote about at the end of last year, with an admirably small reproducer: a copy task works, the same copy task with a loop breaks the play. First item fine, everything after it dead. I found the cause by reading ansible-core source. Ansible rebuilds a connection plugin’s option dictionary before every task — and inside a loop, before every single item. My plugin redirects SSH at the jail host by overriding the host option exactly once, in _connect(). The option reload wiped that redirect, _connect() short-circuits…