runner-images/images/linux/scripts/installers/preimagedata.sh

#!/bin/bash -e

imagedata_file=$IMAGEDATA_FILE
image_version=$IMAGE_VERSION
os_name=$(lsb_release -ds | sed "s/ /\\\n/g")
os_version=$(lsb_release -rs)
image_label="ubuntu-${os_version}"
version_major=${os_version/.*/}
version_wo_dot=${os_version/./}
github_url="https://github.com/actions/virtual-environments/blob"

software_url="${github_url}/ubuntu${version_major}/${image_version}/images/linux/Ubuntu${version_wo_dot}-Readme.md"
releaseUrl="https://github.com/actions/virtual-environments/releases/tag/ubuntu${version_major}%2F${image_version}"

cat <<EOF > $imagedata_file
[
  {
    "group": "Operating System",
    "detail": "${os_name}"
  },
  {
    "group": "Virtual Environment",
    "detail": "Environment: ${image_label}\nVersion: ${image_version}\nIncluded Software: ${software_url}\nImage Release: ${releaseUrl}"
  }
]
EOF