Ryan Prior <rpr...@protonmail.com> writes:
> Hey Guix. > > I've been thinking lately it would be convenient to create certain uniquely > named execution environments on my machine. For example, I might have one > set up with dependencies for my Python webapp & environment variables set to > autoconnect to a Postgres server. I might have another that's got test > dependencies and is containerized, such that it can only access the network > & not the rest of my filesystem. Suppose I name these two "webapp" and > "test" respectively. > > I picture running eg `guix env @webapp -- uvicorn main:app` to start my > server, then `guix env @test -- pytest` to run my tests. > > I might write a wrapper in some scripting language that sets up this kind of > system. Would anybody else be interested in using such a thing? Would it > make sense to integrate this capability into Guix itself? > >Ryan I like this idea! (And adding a built-in alias from "environment" to "env" might be worth it, too.) I actually use an ad-hoc version of this in my ~/.bashrc, using aliases. For example, alias geg='guix environment guix --pure --ad-hoc nano git git:send-email less help2man strace nss-certs' This also lets me add on any ad-hoc packages at the end, like geg dejagnu expect However, an actual `guix env' could do a lot more! Like you allude to, being able to essentially save the options of a `guix environment' invocation would be great: $ guix env --edit @test <lots of packages and environment options> $ guix env @test -- pytest But also imagine portable environments (used, for example, for project dev environments, checked in with the source): --8<---------------cut here---------------start------------->8--- $ guix env --export @myapp-test --pure -C -f guix.scm --ad-hoc strace coreutils (environment "@myapp-test" (load '("guix.scm")) (ad-hoc-packages '("strace" "coreutils" "findutils")) (flags '(pure container))) --8<---------------cut here---------------end--------------->8--- Of course, this isn't entirely reproducible, as packages could change as you update your Guix, even if you give a version spec (the same issue that exists for manifests). So, we could pin the channel used to make the environment: --8<---------------cut here---------------start------------->8--- $ guix env --export @myapp-test --pin-channels ... (environment "@myapp-test" (channels (list (channel (name 'guix) (url ...) (commit ...))) (load '("guix.scm")) (ad-hoc-packages '("strace" "coreutils" "findutils")) (flags '(pure container)))) --8<---------------cut here---------------end--------------->8--- which, when evaluated, would internally do what `guix time-machine --channels file' does. These environments could then be used like: $ guix env -e environment.scm @myapp-test but that's quite long... perhaps we could allow `guix env' to automatically read a "guix.scm" or "environment.scm" file in the current directory, and make the environment definitions within available? ...so I definitely think there's room for such a feature in Guix :) -- Sarah