nsc github base-image describe
Show details for a specific GitHub runner base image.
nsc github base-image describe prints the full details of a single base image, identified by its label (for example ubuntu-26.04). The output includes the image reference, the operating system, the enabled features, and the complete list of installed packages with their versions.
Pass -o json to get a machine-readable representation that is easy to diff between two images, for example to compare ubuntu-26.04 against ubuntu-24.04. You can also browse the same information in the dashboard, for example ubuntu-26.04.
Usage
nsc github base-image describe <label> [flags]Examples
Describe a base image:
$ nsc github base-image describe ubuntu-26.04Describe a base image as JSON:
$ nsc github base-image describe ubuntu-26.04 -o jsonDiff the contents of two base images:
$ diff \
<(nsc github base-image describe ubuntu-24.04 -o json) \
<(nsc github base-image describe ubuntu-26.04 -o json)Arguments
<label>
The label of the base image to describe, for example ubuntu-26.04. Use nsc github base-image list to see the available labels.
Optional Flags
-o, --output string
Output format. Default: plain.
Supported values: plain, json.
--canary
Fetch the canary/staging image instead of the production image.
Related Topics
- nsc github base-image list - List available base images

