Determining an Image's Version

Often it is helpful to determine an image's version. Sometimes, this is as easy as looking at the tag provided by docker image ls or written into the SIF file name, but sometimes this information is lost. Since v4 of the container image, we've been more generous with adding labels to the image and a standard one is included org.opencontainers.image.version which (for our purposes) stores the release that built the image.

We can inspect an image to view its labels. You can find out which runner is being used by running denv check.

Docker/Podman

For docker and podman, the inspect command returns JSON with all of the image manifest details. The jq program just helps us parse this JSON for the specific label we are looking for, but you could just scroll through the output.

docker inspect ldmx/dev:latest \
  | jq 'map(.Config.Labels["org.opencontainers.image.version"])[]'

You can also avoid using jq and scrolling if you provide a Go template.

docker inspect ldmx/dev:latest \
  --format '{{ (index .Config.Labels "org.opencontainers.image.version") }}'

Apptainer

apptainer inspect by default returns just the list of labels, so we can just use grep to select the line with the label we care about. Similar to above, you can also just scroll through the output if you want.

apptainer inspect ldmx_dev_latest.sif | grep org.opencontainers.image.version

Finding SIF Path

denv uses the OCI Image Tag to refer to the images rather than a path to the SIF file which is needed for apptainer inspect to function. Fortunately, you can find the full path to the cached SIF file using an environment variable apptainer defines at runtime.

denv printenv APPTAINER_CONTAINER