Direnv: Integrate with SDKMAN!

[mcandre]

Could we include SDKMAN! alongside rvm and friends, so that direnv works with SDKMAN out of the box?

[zimbatm]

First write a function if your ~/.config/direnv/direnvrc and then document it in
https://github.com/direnv/direnv/wiki/Ruby

[davidecavestro]

This way it works:

1. add to ~/.direnvrc the function

# iterate on pairs of [candidate] [version] and invoke `sdk use` on each of them 
use_sdk() {
  [[ -s "${SDKMAN_DIR}/bin/sdkman-init.sh" ]] && source "${SDKMAN_DIR}/bin/sdkman-init.sh"

  while (( "$#" >= 2 )); do
    local candidate=$1
    local candidate_version=$2
    sdk use $candidate $candidate_version

    shift 2
  done
}

1. use it with pairs of candidates and versions within any .envrc

use sdk java 8.0.222.j9-adpt groovy 2.5.7

i.e. this sets both java and groovy to their specific versions.

[jest]

Normally SDKMAN checks for updates on each sdk call, so going into offline mode in the above snippet speeds things up considerably:

SDK_OFFLINE_MODE=true sdk use $candidate $candidate_version

[luisbelloch]

In latest versions, environment variable is called SDKMAN_OFFLINE_MODE

Check sdkman-availability.sh

[glasser]

A challenge here is that sdkman's main entry point (sdk) is a bash function, and direnv doesn't let you define functions via envrc. So the above works, but it doesn't allow you to actually use sdk unless you add the sdkman-init.sh to your global shell dotfiles... in which case you might as well just use the sdkman_auto_env feature instead of direnv for this anyway.

[glasser]

I take that back: direnv is way less janky than sdkman_auto_env (it knows you might be in a subdirectory of the envrc dir, it reloads when the file changes, etc). So this code above is good, though you still have to also load sdkman-init.sh in your global shell dotfiles if you want to interact with sdk yourself.