On Tue, Jan 23, 2018 at 11:46 PM, Jeff King <peff@xxxxxxxx> wrote: >> The build job on Travis CI always starts with a fresh Docker >> container, so this change doesn't make a difference there. > > I wonder if that is fixable. Installing dependencies into the container > takes quite a lot of time, and is just wasted effort. I agree (because apt-get install phase took forever on my laptop). I've seen people just include a Dockerfile that builds everything in (except things like creating user matching host). First try to fetch it from docker hub (or a local registry but I don't think it applies to us). If not found, rebuild the image with Dockerfile and run a new container with it. Every time somebody changes dockerfile, they are supposed to step the image version up. Of course this is still wasted effort unless somebody pushes images to docker registry and the script has to rebuild the image every single time [1]. Somebody could do that manually. I see docker hub has some automated rebuild feature, perhaps that'll work for us. [1] It still benefits users who run ci scripts manually because the created image will stay in their local machine. -- Duy
