feat: Implement dynamic Kubescape versioning in GitHub Action

[esafak]

Why

Users should not have to wait for someone to update this action, which unfortunately happens very rarely, to benefit from updates to the main utility. We refactor the GitHub Action to build the Docker image at runtime using a user-specified version of kubescape-cli.

What this does

• Introduce a build argument KUBESCAPE_VERSION in the Dockerfile to dynamically set the base image version.
• Convert the action to a composite action in action.yml.
• Add a mandatory version input to action.yml to allow users to specify any kubescape-cli version or 'latest'.
• Implement version resolution logic in action.yml to fetch the latest tag if version is set to 'latest', using the github.token for authentication.
• Update the build step in action.yml to pass the resolved version as the --build-arg KUBESCAPE_VERSION to docker build.
• Update the run step in action.yml to use the resolved version tag for the docker run command.
• Rewrite update.sh to fetch the latest release tag and update the KUBESCAPE_VERSION argument in the Dockerfile using sed.

Testing

I successfully ran the refactored action on my fork: https://github.com/esafak/kubescape-gha/actions/runs/20386459620/job/58588241646

Notes

The kubescape-fix-pr-reviews workflow, which I did not touch, fails with the typo "Scannign scope is not specified. Scanning all frameworks".

[matthyx]

thanks @esafak

[esafak]

Thank you too. Can we get a new Action release soon?

[matthyx]

@esafak I think your code broke the action when referred as main:

2026-01-12T10:21:06.4576176Z ##[group]Run docker build -t kubescape-action: \
2026-01-12T10:21:06.4576587Z �[36;1mdocker build -t kubescape-action: \�[0m
2026-01-12T10:21:06.4576936Z �[36;1m  --build-arg KUBESCAPE_VERSION= \�[0m
2026-01-12T10:21:06.4577344Z �[36;1m  /home/runner/work/_actions/kubescape/github-action/main�[0m
2026-01-12T10:21:06.4608037Z shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
2026-01-12T10:21:06.4608424Z ##[endgroup]
2026-01-12T10:21:06.8531333Z ERROR: failed to build: invalid tag "kubescape-action:": invalid reference format
2026-01-12T10:21:06.8578644Z ##[error]Process completed with exit code 1.
2026-01-12T10:21:06.8723065Z ##[group]Run github/codeql-action/upload-sarif@v2
2026-01-12T10:21:06.8723454Z with:
2026-01-12T10:21:06.8723679Z   sarif_file: results.sarif
2026-01-12T10:21:06.8724014Z   checkout_path: /home/runner/work/helm-charts/helm-charts
2026-01-12T10:21:06.8724763Z   token: ***
2026-01-12T10:21:06.8725004Z   matrix: null
2026-01-12T10:21:06.8725233Z   wait-for-processing: true
2026-01-12T10:21:06.8725498Z ##[endgroup]