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Downloading and Building

The following describes using Singularity for downloading biocontainers on a compute node using the VNC portal app. Once a biocontainer is downloaded, it can be used in a job script.

  • Singularity is available on the compute nodes not login nodes.
  • Singularity can be used to download images from a docker repository and convert to a singularity image (container).
    • Singularity can convert most docker images to singularity images.
  • You can use the HPRC VNC portal app to launch an interactive session on a compute node and download docker images (containers) using singularity.
  • The following example commands are for the VNC terminal not a login node since singularity is not available on the login nodes.
    • You need to load the WebProxy module in the VNC terminal in order to connect a compute node to the internet. Enter the following in the VNC terminal:
module load WebProxy
  • Singularity downloads include the .sif image as well as a cached copy both the same size of around 1GB but the size depends on the contents of the container.
    • By default, singularity uses your home directory to store a cached copy of downloaded docker images. This can cause you to reach your home quota during a download.
    • You can use the $TMPDIR to store the cached copy as well as singularity registry in order to avoid reaching your home directory quota
    • The $TMPDIR on Grace is about 1.4TB and exists only at job runtime on the compute node and does not exist on the login nodes.
  • If you see a warning message about the XGD_RUNTIME_DIR variable, you can unset it.


  • Search the biocontainers website for available containers
  • Here is an example of downloading containers
    • the following will create a singularity image file named blast_2.2.31.sif
singularity pull docker://biocontainers/blast:2.2.31
  • if the install directions show a docker command like

docker pull

add docker:// before the URL when using singularity:

singularity pulldocker://

to build a specific version, change latest to the version:

singularity pulldocker://

Running container commands

  • Since singularity is not available on the login nodes, you can use the HPRC VNC portal app to launch an interactive session on a compute node and run commands found in the container using singularity.
  • Execute a command that is available in the singularity image file:
singularity exec /sw/hprc/sw/bio/containers/blast_2.2.31.sif blastp -h
  • Run the image file to explore available software (not used to update the image)
    • this will start a prompt so you can test software commands that are found in the image
singularity run /sw/hprc/sw/bio/containers/blast_2.2.31.sif

Usage in a job script

  • Once you figure out the commands you want to use, you can create a job script and use singularity to run the software command available in the container. (using full or relative path for the .sif file or just the .sif file name if it is located in the same directory as your job script)
singularity exec /sw/hprc/sw/bio/containers/blast_2.2.31.sif blastp -query seqs.fa -db hg19 -outfmt 10 -out blastout.csv -num_threads 28
  • There are some available biocontainers on Grace at


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