The following examples runs in GitLab CI in a repository containing a Docker image's definition and contents. Triggered by a commit, the pipeline builds the image. If the commit was to the default branch, it uses Docker Scout to get a CVE report. If the commit was to a different branch, it uses Docker Scout to compare the new version to the current published version.
Steps#
First, set up the rest of the workflow. There's a lot that's not specific to Docker Scout but needed to create the images to compare.
Add the following to a .gitlab-ci.yml
file at the root of your repository.
docker-build:
image: docker:latest
stage: build
services:
- docker:dind
before_script:
- docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
# Install curl and the Docker Scout CLI
- |
apk add --update curl
curl -sSfL https://raw.githubusercontent.com/docker/scout-cli/main/install.sh | sh -s --
apk del curl
rm -rf /var/cache/apk/*
# Login to Docker Hub required for Docker Scout CLI
- docker login -u "$DOCKER_HUB_USER" -p "$DOCKER_HUB_PAT"
This sets up the workflow to build Docker images with Docker-in-Docker mode, running Docker inside a container.
It then downloads curl
and the Docker Scout CLI plugin, logs into the Docker
registry using environment variables defined in your repository's settings.
Add the following to the YAML file:
script:
- |
if [[ "$CI_COMMIT_BRANCH" == "$CI_DEFAULT_BRANCH" ]]; then
tag=""
echo "Running on default branch '$CI_DEFAULT_BRANCH': tag = 'latest'"
else
tag=":$CI_COMMIT_REF_SLUG"
echo "Running on branch '$CI_COMMIT_BRANCH': tag = $tag"
fi
- docker build --pull -t "$CI_REGISTRY_IMAGE${tag}" .
- |
if [[ "$CI_COMMIT_BRANCH" == "$CI_DEFAULT_BRANCH" ]]; then
# Get a CVE report for the built image and fail the pipeline when critical or high CVEs are detected
docker scout cves "$CI_REGISTRY_IMAGE${tag}" --exit-code --only-severity critical,high
else
# Compare image from branch with latest image from the default branch and fail if new critical or high CVEs are detected
docker scout compare "$CI_REGISTRY_IMAGE${tag}" --to "$CI_REGISTRY_IMAGE:latest" --exit-code --only-severity critical,high --ignore-unchanged
fi
- docker push "$CI_REGISTRY_IMAGE${tag}"
This creates the flow mentioned previously. If the commit was to the default branch, Docker Scout generates a CVE report. If the commit was to a different branch, Docker Scout compares the new version to the current published version. It only shows critical or high-severity vulnerabilities and ignores vulnerabilities that haven't changed since the last analysis.
Add the following to the YAML file:
rules:
- if: $CI_COMMIT_BRANCH
exists:
- Dockerfile
These final lines ensure that the pipeline only runs if the commit contains a Dockerfile and if the commit was to the CI branch.
Video walkthrough#
The following is a video walkthrough of the process of setting up the workflow with GitLab.