This is the default behavior of this configuration profile.
Using this profile, if no singularity image are available, one will be downloaded from dockerhub, and converted to a Singularity image before execution of the pipeline.
It is also possible to specify the singularity profile:
Example: `nextflow run -profile munin,singularity`
A local copy of the iGenomes resource has been made available on the MUNIN cluster so you should be able to run the pipeline against any reference available in the `igenomes.config` specific to the nf-core pipeline.