Conda#

Conda is an open-source environment and package manager. Miniconda is a free installer for Conda and Python and comes with a few other packages. Anaconda is also a package manager that has a much larger number of packages pre-installed.

Managing Conda Environments#

Creating Environments#

Note

We recommend avoiding building Conda environments in your /home, for its space quota. Instead, Use /work, which can be requested by PIs for groups in need of space /work.

Installing local virtual environment using Conda is recommended on the cluster. You can have multiple environments with different packages for each, which allows project’s environments to be independent of others. You only have to load the anaconda3 module.

From the login node, log-in to a compute node.

Request one node on the short partition with 1 CPU core. Then, load the anaconda3/2022.05 module.#

srun --partition=short --nodes=1 --cpus-per-task=1 --pty /bin/bash
module load anaconda3/2022.05

To create a new Conda environment where <environment-name> is the path and name. You can see a list of your existing environments with conda env list.

conda create --prefix=/<path>/<environment-name> python=3.11 anaconda

Follow the prompts to complete the Conda install, then activate the environment.

source activate /<path>/<environment-name>

Your command line prompt will then include the path and name of environment.

(/<path>/<environment-name>) [<username>@c2001 dirname]$

Tip

The conda config --set env_prompt '({name}) ' command modifies your .condarc to show only the environment, which displays as follows:

(<environment-name>) [<username>@c2000 dirname]$

With your Conda environment activated you can install a specific package with

conda install [packagename]

To deactivate the current active Conda environment

conda deactivate

To delete a Conda environment and all of its related packages, run:

conda remove -n yourenvironmentname --all

Listing Environments#

You can view the environments you’ve created in your home directory by using the following command

conda env list

# conda environments:
#
MlGenomics               $HOME/.conda/envs/MlGenomics
base                     $HOME/miniconda3

To list the software packages within a specific environment, use

conda list --name env_name

If you’ve created an environment in a different location, you can still list its packages using:

conda list --prefix /path/to/env

Exporting Environment#

For ensuring reproducibility, it’s recommended to export a list of all packages and versions in an environment to an environment file. This file can then be used to recreate the exact environment on another system or by another user. It also serves as a record of the software environment used for your analysis.

Removing Environments#

When you need to remove an environment located in your home directory, execute:

conda env remove --name env_name

For environments located elsewhere, you can remove them using:

rm -rf /path/to/env

Clean Conda Environment#

To remove packages that are no longer used by any environment and any downloaded tarballs stored in the conda package cache, run:

conda clean --all

By following these guidelines, you can efficiently manage your Conda environments and packages, ensuring reproducibility and a clean system.

Using Miniconda#

This procedure assumes that you have not installed Miniconda. If you need to update Miniconda, do not follow the installation procedure. Use conda update. This procedure uses the Miniconda3 version with Python version 3.8 in step 2, although there are other versions you can install (e.g., 3.9 or 3.11).

Installing Miniconda#

Attention

Make sure to log on to a compute node.

srun --partition=short --nodes=1 --cpus-per-task=1 --pty /bin/bash

Download Miniconda, check the hash key, and install as follows:

wget --quiet https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh
sha256sum Miniconda3-latest-Linux-x86_64.sh
bash Miniconda3-latest-Linux-x86_64.sh -b -p <dir>

Where <dir> is the full path to your desired installation directory (e.g., /work/mygroup/miniconda3).

Activate the base Miniconda environment

source <dir>/bin/activate

You can now create a new environment with this command where we are using python version 3.8:

conda create --name my-py38env python=3.8

Type y if asked to proceed with the installation.

Now you can activate your new environment

conda activate my-py38env

To deactivate the environment, type conda deactivate. You can type this command again to deactivate the base Miniconda environment.

Conda and `.bashrc`#

In addition to editing your .bashrc file as outlined in the example above, programs you install can also modify your .bashrc file. For example, if you follow the procedure outlined in Using Miniconda, there may be a section added to your .bashrc file (if you didn’t use the -b batch option) that automatically loads your conda environment every time you sign in to Discovery. See the figure below for an example of this:

# .bashrc

# Source global definitions
if [ -f /etc/bashrc ]; then
	. /etc/bashrc
fi

# Uncomment the following line if you don't like systemctl's auto-paging feature:
# export SYSTEMD_PAGER=

# User specific aliases and functions

# >>> conda initialize >>>
# !! Contents within this block are managed by 'conda init' !!
__conda_setup="$('/home/$USER/miniconda3/bin/conda' 'shell.bash' 'hook' 2> /dev/null)"
if [ $? -eq 0 ]; then
    eval "$__conda_setup"
else
    if [ -f "/home/$USER/miniconda3/etc/profile.d/conda.sh" ]; then
        . "/home/$USER/miniconda3/etc/profile.d/conda.sh"
    else
        export PATH="/home/$USER/miniconda3/bin:$PATH"
    fi
fi
unset __conda_setup
# <<< conda initialize <<<

You should not modify this section in the .bashrc file directly. If it was changed, remove this section manually using a file editor.

Caution

We recommend removing the conda initialization section from your .bashrc as it may interfere with the correct startup environment when using Open OnDemand apps. You should always load your Conda environment after your job has already started.

If you need help with your .bashrc file or would like it restored to its default, reach out to the RC team at mailto:rchelp@northeastern.edu, and we can provide you with a new default .bashrc file and help troubleshoot issues with the file.

Conda#

Managing Conda Environments#

Creating Environments#

Listing Environments#

Exporting Environment#

Removing Environments#

Clean Conda Environment#

Using Miniconda#

Installing Miniconda#

Conda and .bashrc#

Conda Best Practices#

Conda and `.bashrc`#