Using On-Demand Scanning as part of your Cloud Build pipeline allows you to block builds if the container image has vulnerabilities with a severity matching a predefined level.
This tutorial shows you how to use Cloud Build to build your container image from the source code, scan it for vulnerabilities, check the severity levels of the vulnerabilities, and push the image to Artifact Registry if there are no vulnerabilities of a specific severity level.
You can use a similar approach to block a build if an existing built image has vulnerabilities that match the severity level.
Objectives
- Build an image with Cloud Build.
- Scan the built image with On-Demand Scanning.
- Assess acceptable vulnerability levels.
- Store the image in Artifact Registry.
Costs
This tutorial uses the following billable components of Google Cloud:
To generate a cost estimate based on your projected usage, use the pricing calculator. New Google Cloud users might be eligible for a free trial.
When you finish this tutorial, you can avoid continued billing by deleting the resources you created. For more information, see Cleaning up.
New Google Cloud users might be eligible for a free trial.
Before you begin
- Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
-
In the Google Cloud Console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Cloud project. Learn how to confirm that billing is enabled for your project.
- Enable the On-Demand Scanning, Cloud Build, and Artifact Registry APIs.
- Install and initialize the Cloud SDK.
- Grant the IAM role On-Demand Scanning Admin to your Cloud Build service account.
Prepare your source file
For this tutorial you are going to build an image from a Dockerfile. A Dockerfile is a source file that contains instructions for Docker to build an image.
Open a terminal, create a new directory named
ods-tutorial
, and navigate to it:mkdir ods-tutorial && cd ods-tutorial
Create a file named
Dockerfile
with the following contents:# Debian10 image FROM gcr.io/google-appengine/debian10:latest # Ensures that the built image is always unique RUN apt-get update && apt-get -y install uuid-runtime && uuidgen > /IAMUNIQUE
Create an Artifact Registry repository
Set the project ID to the same project where you enabled the APIs:
gcloud config set project PROJECT_ID
Create a Docker repository named
ods-build-repo
in the locationus-central1
:gcloud artifacts repositories create ods-build-repo --repository-format=docker \ --location=us-central1 --description="Repository for scan and build"
Verify that your repository was successfully created:
gcloud artifacts repositories list
Build your container
In this section you will run your build pipeline using a build config file. A build config file instructs Cloud Build how to perform several tasks based on your specifications.
In the
ods-tutorial/
folder, create the filecloudbuild.yaml
with the following contents:steps: - id: build name: gcr.io/cloud-builders/docker entrypoint: /bin/bash args: - -c - | docker build -t us-central1-docker.pkg.dev/$_PROJECT_ID/ods-build-repo/ods-test:latest -f ./Dockerfile . && docker image inspect us-central1-docker.pkg.dev/$_PROJECT_ID/ods-build-repo/ods-test:latest --format \ '{{index .RepoTags 0}}@{{.Id}}' > /workspace/image-digest.txt && cat image-digest.txt - id: scan name: gcr.io/cloud-builders/gcloud entrypoint: /bin/bash args: - -c - | gcloud artifacts docker images scan us-central1-docker.pkg.dev/$_PROJECT_ID/ods-build-repo/ods-test:latest \ --format='value(response.scan)' > /workspace/scan_id.txt - id: severity check name: gcr.io/cloud-builders/gcloud entrypoint: /bin/bash args: - -c - | gcloud artifacts docker images list-vulnerabilities $(cat /workspace/scan_id.txt) \ --format='value(vulnerability.effectiveSeverity)' | if grep -Fxq $_SEVERITY; \ then echo 'Failed vulnerability check' && exit 1; else exit 0; fi - id: push name: gcr.io/cloud-builders/docker entrypoint: /bin/bash args: - -c - | docker push us-central1-docker.pkg.dev/$_PROJECT_ID/ods-build-repo/ods-test:latest images: ['us-central1-docker.pkg.dev/$_PROJECT_ID/ods-build-repo/ods-test:latest']
Start the build:
gcloud builds submit --substitutions=_PROJECT_ID=PROJECT_ID,_SEVERITY=SEVERITY \ --config cloudbuild.yaml
Where
- PROJECT_ID is your project ID.
SEVERITY is the severity level for allowed vulnerabilities. If the image contains vulnerabilities of the given severity, the build fails. The possible values are:
CRITICAL
HIGH
MEDIUM
LOW
MINIMAL
See the On-Demand Scanning severity levels section for more information.
If you set a CRITICAL
severity level as the blocking level for this example,
the build is successful since the image does not contain critical-level
vulnerabilities. The image is be pushed to Artifact Registry. The output is
similar to the following:
DONE
--------------------------------------------------------------------------------------------------------------------------------------------
ID CREATE_TIME DURATION SOURCE IMAGES STATUS
abb3ce73-6ae8-41d1-9080-7d74a7ecd7bc 2021-03-15T06:50:32+00:00 1M48S gs://ods-tests_cloudbuild/source/1615791031.906807-a648d10faf4a46d695c163186a6208d5.tgz us-central1-docker.pkg.dev/ods-tests/ods-build-repo/ods-test (+1 more) SUCCESS
For a lower level, for example MEDIUM
, the build fails and the output is
similar to the following:
Step #2 - "severity check": Failed vulnerability check
Finished Step #2 - "severity check"
ERROR
ERROR: build step 2 "gcr.io/cloud-builders/gcloud" failed: step exited with non-zero status: 1
Cleaning up
To avoid incurring charges to your Google Cloud account for the resources used in this tutorial, either delete the project that contains the resources, or keep the project and delete the individual resources.
Delete the project
- In the Cloud Console, go to the Manage resources page.
- In the project list, select the project that you want to delete, and then click Delete.
- In the dialog, type the project ID, and then click Shut down to delete the project.
Delete individual resources
Before you remove the repository, ensure that any images you want to keep are available in another location.
To delete the repository:
Console
Open the Repositories page in the Cloud Console.
In the repository list, select the
ods-build-repo
repository.Click Delete.
gcloud
To delete ods-build-repo
the repository, run the following
command:
gcloud artifacts repositories delete ods-build-repo --location=us-central1