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Yujin
Yujin

Posted on • Originally published at jinyuz.dev on

Switching from pyenv, rbenv, goenv and nvm to asdf

#fish #asdf #pyenv #nvm

So, there was a time when I was only developing applications using Python. And so I found out about virtual environments.And then after a couple of months, I discovered pyenv.

It also came to a time I had to work on multiple projects that uses different versions of nodejs and searched something similarso I installed nvm.

Then, I was required to work on a Ruby project so I installed rbenv.

And since golang was one of the new shiny objects that kinda got my interest, I went on and installed goenv.

Everything was fine until I kinda felt my config.fish file got bloated and somehow nvm was kinda slowing down my shell startup.

I did do some optimizations such as lazy loading nvm and used a fish plugin called fish-nvm.

And then one day, I found out about asdf-vm.

At first, I was quite hesitant to install it since it would kinda disrupt my work flow with python projects since I heavily use pyenv virtualenv <version> <name>.

But I did feel that the benefits of using asdf-vm outweighs the cons so I went ahead and proceeded.

Installation 

$ git clone https://github.com/asdf-vm/asdf.git ~/.asdf --branch v0.7.8
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asdf has a pretty good documentation to be honest. Despite brew being my go to package manager, I chose git as my installation method.My reason is that asdf requires me to add this line in my config.fish

source (brew --prefix asdf)/asdf.fish
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and the brew --prefix adsf is just too slow compared to just having this

source $HOME/.asdf/asdf.fish
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Next, for the auto completions just run this command in your terminal:

$ mkdir -p ~/.config/fish/completions; and cp ~/.asdf/completions/asdf.fish ~/.config/fish/completions
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Restart your shell so that PATH changes take effect!

You can checkout a more detailed documentation here: https://asdf-vm.com/#/core-manage-asdf-vm?id=install

Before, my config.fish looked something like this:

# pyenv
set -gx PYENV_ROOT $HOME/.pyenv
set -gx PYTHON_BUILD_ARIA2_OPTS "-x 10 -k 1M" # Use aria2c when downloading
contains $PYENV_ROOT/bin $fish_user_paths; or set -Ua fish_user_paths $PYENV_ROOT/bin
status --is-interactive; and pyenv init - | source
status --is-interactive; and pyenv virtualenv-init - | source

# goenv
set -gx GOENV_GOPATH_PREFIX $HOME/.go
status --is-interactive; and goenv init - | source

# rbenv
status --is-interactive; and rbenv init - | source

# Set nvm aliases and add to path
set -gx nvm_alias_output $HOME/.node_aliases
contains $nvm_alias_output $fish_user_paths; or set -Ua fish_user_paths $nvm_alias_output
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After

# pyenv (asdf still uses pyenv under the hood)
set -gx PYTHON_BUILD_ARIA2_OPTS "-x 10 -k 1M" # Use aria2c when downloading

# asdf
source $HOME/.asdf/asdf.fish
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Installing pyenv, rbenv, goenv, and nvm replacements

Again, most of the things I put here just came from the documentation: https://asdf-vm.com/#/core-manage-plugins?id=add

pyenv replacement 

$ asdf plugin add python
$ asdf install python latest:3 # At the moment of writing this, it installed 3.8.4
$ asdf global python 3.8.4 # This sets python 3.8.4 as our default python version
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rbenv replacement 

$ asdf plugin add ruby
$ asdf install ruby latest # We can omit the version number. Currently installs 2.7.1
$ asdf global ruby 2.7.1
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goenv replacement 

$ asdf plugin add golang
$ asdf install golang latest # 1.14.6
$ asdf global golang 1.14.6
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nvm replacement 

$ asdf plugin add nodejs
$ asdf install nodejs 12.18.2
$ asdf global nodejs 12.18.2
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Using asdf global creates a file under your HOME directory called .tool-versions

$ cat ~/.tool-versions
python 3.8.4
ruby 2.7.1
golang 1.14.6
nodejs 12.18.2
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This lets asdf know which versions to use. And of course, in contrast to global,there is also the local keyword that creates another .tool-versions.This is useful when projects require different version.

$ cd ~/project1
$ asdf local python 3.7.5
$ python --version # Uses the python version specified in .tool-versions
3.7.5
$ cd ~/project2
$ python --version # Uses the python version specified in ~/.tool-versions
3.8.4
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asdf has a lot of plugins available. You can check them out here: https://github.com/asdf-vm/asdf-plugins

Extras

In order to accommodate my work flow when I was still using pyenv virtualenv,I created a function that behaves quite similar to pyenv virtualenv.

$ touch ~/.config/fish/functions/venv.fish
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And paste the following:

function venv --argument-names 'python_version' --description 'Create virtualenv named the same as current directory'
  set -l python_bin

  if not test -n "$python_version"
    # Use default python version set by asdf
    set python_bin ($HOME/.asdf/bin/asdf which python)
  else
    set python_bin $ASDF_DIR/installs/python/$python_version/bin/python
  end

  set -l venv_name (basename $PWD | tr . -)

  echo
  if not test -e $python_bin
    echo "Python version `$python_version` is not installed."
    return 1
  end

  echo Creating virtualenv `$venv_name`
  $python_bin -m venv $HOME/.virtualenvs/$venv_name
  source $HOME/.virtualenvs/$venv_name/bin/activate.fish
end
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Whenever I’m inside a python project, I just need to type venv or venv <python_version>and it will automatically create a virtualenv under ~/.virtualenvs using the current directory name.

In order to automatically activate the virtualenv when cding to a project, do the following:

$ touch ~/.config/fish/conf.d/__auto_venv.fish
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And paste the following:

function __auto_venv --on-variable PWD --description "Automatically activate python venv"
  set -l venv_name (basename $PWD | tr . -)

  if test -d $HOME/.virtualenvs/$venv_name
    source $HOME/.virtualenvs/$venv_name/bin/activate.fish
  end
end
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Cool! Not only did I reduce the lines in my config.fish, I could also notice a decreased startup time which is a good thing!

You can also check out my dotfiles in my GitHub repository: https://github.com/yujinyuz/dotfiles

I hope this article helped you! You can leave a comment below and I’ll try to answer them as fast as I can.

Thanks for reading! 🎉

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