aactivator
is a simple tool that automatically sources ("activates") and
unsources a project's environment when entering and exiting it.
Key features of aactivator include:
bash
and zsh
.aactivator supports Python 2.7, 3.4+; it has no dependencies besides the standard library.
aactivator provides a simple interface for projects, via two files at the root of the project:
.activate.sh
, which is sourced by the shell on enter.
If working with Python virtualenvs, it usually makes the most sense to
symlink .activate.sh
to the bin/activate
file inside your virtualenv.
For example, ln -s venv/bin/activate .activate.sh
. This symlink can be
checked directly into git (just make sure to use a relative symlink, like in
the command before).
.deactivate.sh
, which is sourced by the shell on exit.
For Python projects, this is typically just a one-line file that contains
deactivate
, though it can be modified to suit your particular project.
Note that neither of these files need to be executable or contain a shebang. This is because they are sourced (run inside your current shell) and not executed.
We recommend adding aactivator
to your shell's config. It will stay out of
your way during regular usage, and you'll only ever notice it doing its job
when you cd
into a project directory that supports aactivator.
You first need to install the aactivator
binary somewhere on your system. You
have a few options:
Just copy the aactivator.py
script somewhere on
your system and make it executable (chmod +x aactivator.py
). It has no
dependencies besides the Python standard library.
Install it via pip (pip install aactivator
). You can install system-wide,
to your home directory, or into a virtualenv (your preference).
Install the Debian package. This is the best option for system-wide automated installations, and gives you other niceties like a man-page. You can find pre-built Debian packages under the Releases GitHub tab.
Once you have aactivator
installed, you need to enable it on login. To do
that, just add this line to the .bashrc
(or .zshrc
for zsh) file in your
home directory:
eval "$(aactivator init)"
(You may need to prefix aactivator
with the full path to the binary if you
didn't install it somewhere on your $PATH
).
Automatically sourcing virtualenvs is a huge boon to large projects. It means
that you can directly execute tools like pytest
, and also that the project
can register command-line tools (via setuptools' console_scripts
entrypoint)
for use by contributors.
We tried pretty hard to make this not a giant arbitrary-code-execution vector. There are two main protections:
aactivator
asks before sourcing previously-unseen directories. You can
choose between not sourcing once, never sourcing, or sourcing.
You shouldn't choose to source projects whose code you don't trust. However, it's worth keeping in mind that the same consideration exists with running tests, building the virtualenv, or running any of that project's code. Sourcing the virtualenv is just as dangerous as any of these.
aactivator
refuses to source environment files which can be modified by
others. It does this by recursing upwards from the current directory until
hitting a filesystem boundary, and checking that the file (and all of its
parents) can be modified by only you and root
.
Some alternatives to aactivator
already exist. For example:
These alternatives all have at least one of the following problems (compared to aactivator):
cd
builtin (which means things like popd
or other
methods of changing directories don't work)zsh