Mix task to start only certain applications?

You can use:

$ mix run --no-start -e "{:ok, _} = Application.ensure_all_started(:foo)"

To start only one application. Just remember to add --no-halt if you run it outside of IEx.

I typically use mix cmd --app umbrella_child mix run or pushd/popd for that, together with Tmux splits/panes, which can optionally be automated with projects like tmuxinator, teamocil, or a recent entrant called dmux.

Our primary repository at work is a large umbrella where most development efforts target one web frontend plus data and batch processing, so around a quarter of the total repo footprint, and this model works well in that scenario.

Nice, thanks for the mix command!

We use tmuxinator also, but I’m not entirely happy with it, thanks for those alternatives, going to check them out.

How do you use pushd and popd, I’m not getting that part.

pushd and popd are named after pushing and popping a stack from traditional computer science, so it looks something like:

# stores your current working directory
pushd apps/umbrella_child
# one-off commands, this approach doesn't work as well for something that stays running
mix ecto.migrate
# restores your working directory as it was prior to the previous pushd command
popd