installation.md

Installation

We provide an installer, as described in the main README.md of the project. This script installs a Popper executable (popper binary), and optionally places it on /usr/local/bin/ so that it is available globally on your system. The script tells you what is doing and asks for confirmation before moving the file to /usr/local/bin.

The installer script is the preferred method if Docker is the container engine available in your system, as in this case Popper runs in Docker itself. For other container engines such as Singularity, you will need to install the Python Package (see "Install in a Virtualenv" section). For setting up a development environment, see the "Development Setup" section.

Requirements

Popper only runs on Linux or MacOS. On Windows systems, Popper can be executed in the Windows Subsystem for Linux (WSL2). The only requirement for the main installation approach (installer script described above), is to have Docker installed. Consult the official Docker documentation for detailed instructions on how to install Docker.

Running workflows on Singularity requires Singularity 3.2+ and can only be done with Popper installed via via Pip (section below), which in turn assumes Python 3.6+.

Install in a Virtualenv

If you intent to use Popper for running workflows on Docker, we recommend using the installer script as described at the beginning of this page. Installing via Pip is only necessary if you intend to workflows on Singularity or if you are setting up a development environment.

To install Popper via Pip, we highly recommend doing it in a virtual environment using virtualenv, as opposed to installing globally on your system (avoid doing sudo pip install... or pip install --user...), as this usually results in scenarios that are difficult to debug.

The following installation instructions assume that virtualenv is installed in your environment (see here for more). Once virtualenv is available in your machine, we proceed to create a folder where we will place the Popper virtual environment:

# create a folder for storing virtual environments
mkdir $HOME/virtualenvs

We then create a virtualenv for Popper. This will depend on the method with which virtualenv was installed:

# 1) if virtualenv was installed via package, e.g.:
# - apt install virtualenv (debian/ubuntu)
# - yum install virtualenv (centos/redhat)
# - conda install virtualenv (conda)
# - pip install virtualenv (pip)
virtualenv $HOME/virtualenvs/popper

# OR
#
# 2) if virtualenv installed via Python 3.6+ module
python -m venv $HOME/virtualenvs/popper

NOTE: in the case of conda, we recommend the creation of a new environment before virtualenv is installed in order to avoid issues with packages that might have been installed previously.

We then load the environment we just created above:

source $HOME/virtualenvs/popper/bin/activate

Finally, we install Popper in this environment using pip:

pip install popper

To test all is working as it should, we can show the version we installed:

popper version

And to get a list of available commands:

popper --help

NOTE: given that we are using virtualenv, once the shell session ends (when we close the terminal window or tab), the environment gets unloaded and newer sessions (new window or tab) will not have the popper command available in the PATH variable. In order to have the environment loaded again we need to execute the source command (see above). In the case of conda we need to load the Conda environment (conda activate command).

Development Setup

To create a development environment for hacking on Popper, you can execute the following:

cd $HOME/

# create virtualenv
virtualenv $HOME/venvs/popper
source $HOME/venvs/popper/bin/activate

# clone popper
git clone git@github.com:getpopper/popper
cd popper

# install popper from source
pip install -e src/[dev]

the -e flag passed to pip tells it to install the package from the source folder, and if you modify the logic in the popper source code you will see the effects when you invoke the popper command. So with the above approach you have both (1) popper installed in your machine and (2) an environment where you can modify popper and test the results of such modifications.