Environment variables

Making environment variables available to jobs

It is a common technique to use environment variables to pass information, such as configuration options, into a container. The option --env can be used to specify an environment variable in the form of a key-value pair separated by “=”. This option can be specified multiple times to set multiple environment variables. For example:

prominence create --env LOWER=4.5 --env UPPER=6.7 test/container

Default environment variables

The following environment variables will be set by default:

  • PROMINENCE_CPUS: the number of CPUs available (which could be larger than what was requested)
  • PROMINENCE_MEMORY: the amount of memory in GB available (which could be larger than what was requested)
  • PROMINENCE_NODES: the number of nodes in the job
  • PROMINENCE_NODE_NUM: the id of the node in a multi-node job, starting from 0
  • PROMINENCE_CONTAINER_RUNTIME: the container runtime in use, either singularity or udocker
  • PROMINENCE_JOB_ID: the id of the job
  • PROMINENCE_WORKFLOW_ID: the id of the associated workflow, if applicable
  • PROMINENCE_TOKEN: token which can be used to authenticate against the PROMINENCE REST API (a unique token is generated per job, and is valid for the lifetime of the job)