If you’re like me – you live in the middle of nowhere, in New Zealand, without fiber let alone any DSL, and you develop a lot of software using docker – you might find your build\/deploy cycle a bit painful, since many docker builds download packages.<\/p>\n\n\n\n
Even if you are an unusual case – you live in an urban area with good espresso on every corner, scarce parking, and fiber to the couch (complete with 5G) – retrieving lots of packages from disk\/SSD is still faster than fiber.<\/p>\n\n\n\n
Running a docker pull through cache<\/a> can help if you have a few machines pulling the same images. However, you sometimes you still need to actually build those images locally, and the build process can involve a lot of apt-get’ing or apk add’ing.<\/p>\n\n\n\n To help with package retrieval over HTTP, you can run apt-cacher-ng<\/a>. That’s great if you have a way to convince your docker build to use the cache (e.g. via an environment variable). However it’d be even nicer not to have to do anything special.<\/p>\n\n\n\n The missing piece in the puzzle, is a transparent HTTP proxy (like squid), that knows how to redirect requests to apt-cacher-ng. This is what I do and it makes docker builds really fast (at least, the package retrieval part). Using a relatively old squid redirector, jesred<\/a>, squid intercepts common package retrieval URLs and pass them to apt-cacher-ng.<\/p>\n\n\n\n Here’s part of my \/etc\/jesred.conf:<\/p>\n\n\n\n Of course, your squid installation has to be set up to do transparent caching on port 80, and has to reference jesred in \/etc\/squid\/squid.conf:<\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" If you’re like me – you live in the middle of nowhere, in New Zealand, without fiber let alone any DSL, and you develop a lot of software using docker – you might find your build\/deploy cycle a bit painful, since many docker builds download packages. Even if you are an unusual case – you … <\/p>\nregex ^http:\/\/((.*)archive.ubuntu.com\/ubuntu\/(dists|pool)\/.*)$ http:\/\/localho\nst:3142\/\\1\nregex ^http:\/\/(security.ubuntu.com\/ubuntu\/(dists|pool)\/.*)$ http:\/\/localhost:\n3142\/\\1\nregex ^http:\/\/(dl-cdn.alpinelinux.org\/alpine.+)$ http:\/\/localhost:3142\/\\1\nregex ^http:\/\/(.*cdn.*.debian.org\/.+)$\thttp:\/\/localhost:3142\/\\1\nregex ^http:\/\/(deb.debian.org\/.+)$ http:\/\/localhost:3142\/\\1\nregex ^http:\/\/(archive.raspberrypi.org\/debian\/.+)$ http:\/\/localhost:3142\/\\1\n<\/code><\/pre>\n\n\n\nredirect_program \/usr\/lib\/squid\/jesred<\/code><\/pre>\n\n\n\n