Vilicus — A overseer for security scanning of container images

4 min readMar 13, 2021

Vilicus is an open-source tool that orchestrates security scans of container images(Docker/OCI) and centralizes all results into a database for further analysis and metrics.

Why scan for vulnerabilities?

A recent analysis of around 4 million Docker Hub images by cyber security firm Prevasio found that 51% of the images had exploitable vulnerabilities. A large number of these were cryptocurrency miners, both open and hidden, and 6,432 of the images had malware.
https://www.infoq.com/news/2020/12/dockerhub-image-vulnerabilities/

Image from https://prevasio.com/static/web/viewer.html?file=/static/Red_Kangaroo.pdf

Docker image security scanning is a process for finding security vulnerabilities within your Docker image files.
Typically, image scanning works by parsing through the packages or other dependencies that are defined in a container image file, then checking to see whether there are any known vulnerabilities in those packages or dependencies.
https://resources.whitesourcesoftware.com/blog-whitesource/docker-image-security-scanning

How does it work?

There are many tools to scan container images for vulnerabilities such as Anchore, Clair, and Trivy. But sometimes the results from the same image can be different. And this project comes to help the developers to improve the quality of their container images by finding vulnerabilities and thus addressing them with agnostic sight from vendors.

Some articles comparing the scanning tools:

Architecture

Cached Database

Vilicus updates daily the vendor databases with the latest changes in the vulns DBs.

Using a strategy to storage the database data in layers of docker images, the whole platform is ready to use in minutes instead of hours. Starting the sync feed with vulns from scratch can take at least 6 hours.

Check the strategy used in Anchore, Clair and Trivy

Local Registry

Vilicus provides a local registry, so you can build a local image and scanning it without pushing it to a remote repository.

$ docker build -t localhost:5000/local-image:my-tag .$ curl -o docker-compose.yml https://raw.githubusercontent.com/edersonbrilhante/vilicus/main/deployments/docker-compose.yml$ docker-compose up -d$ IMAGE=localregistry.vilicus.svc:5000/local-image:my-tag$ docker run -v ${PWD}/artifacts:/artifacts \
  --network container:vilicus \
  vilicus/vilicus:latest \
  sh -c "dockerize -wait http://vilicus:8080/healthz -wait-retry-interval 60s -timeout 2000s vilicus-client -p /opt/vilicus/configs/conf.yaml -i ${IMAGE}  -t /opt/vilicus/contrib/sarif.tpl -o /artifacts/results.sarif"

GitHub Action

GitHub Actions makes it easy to automate all your software workflows, now with world-class CI/CD. Build, test, and deploy your code right from GitHub. Make code reviews, branch management, and issue triaging work the way you want.
https://github.com/features/actions

Vilicus provides a GitHub action to help you scanning container images in your CI/CD.

Container scanning

A scan can be done using a remote image and a local image. Using a remote repository such as docker.io the image will be `docker.io/your-organization/image:tag`:

- name: Scan image
  uses: edersonbrilhante/vilicus-github-action@main
  with:
    image: "docker.io/myorganization/myimage:tag"

And to use a local image its need to tag as `localhost:5000/image:tag`:

- name: Scan image
  uses: edersonbrilhante/vilicus-github-action@main
  with:
    image: "localhost:5000/myimage:tag"

Full example

Complete example with steps for cleaning space, building local image, Vilicus scanning, and uploading results to GitHub Security

name: Container Image CI
on: [push]
jobs:
  build
    runs-on: ubuntu-latest
    steps:
      - name: Maximize Build Space
        uses: easimon/maximize-build-space@master
        with:
          root-reserve-mb: 512
          swap-size-mb: 1024
          remove-dotnet: 'true'
          remove-android: 'true'
          remove-haskell: 'true'
      
     - name: Checkout branch
       uses: actions/checkout@v2- name: Build the Container image
       run: docker build -t localhost:5000/local-image:${GITHUB_SHA} .
     - name: Vilicus Scan
       uses: edersonbrilhante/vilicus-github-action@main
       with:
         image: localhost:5000/local-image:${{ github.sha }}     - name: Upload results to github security
       uses: github/codeql-action/upload-sarif@v1
       with:
         sarif_file: artifacts/results.sarif