Making HTTP requests from a container that has no curl, using bash /dev/tcp

Edit: This has generated a nice discussion on Hacker News &ndash; check it out too! I needed to check that one container could reach another over an internal Docker network: a plain GET /health against a service on a shared network. The obvious move is curl http://service:8642/health . But this app image was stripped right down, with no curl or wget and nothing else around that I could use to open…