Docker Scout analyzes image contents and generates a detailed report of packages and vulnerabilities that it detects. It can provide you with suggestions for how to remediate issues discovered by image analysis.
This guide takes a vulnerable container image and shows you how to use Docker Scout to identify and fix the vulnerabilities, compare image versions over time, and share the results with your team.
Step 1: Setup#
This example project contains a vulnerable Node.js application that you can use to follow along.
- Clone its repository:
console
$ git clone https://github.com/docker/scout-demo-service.git
- Move into the directory:
console
$ cd scout-demo-service
-
Make sure you're signed in to your Docker account, either by running the
docker login
command or by signing in with Docker Desktop. -
Build the image and push it to a
<ORG_NAME>/scout-demo:v1
, where<ORG_NAME>
is the Docker Hub namespace you push to.
console
$ docker build --push -t <ORG_NAME>/scout-demo:v1 .
Step 2: Enable Docker Scout#
Docker Scout analyzes all local images by default. To analyze images in remote repositories, you need to enable it first. You can do this from Docker Hub, the Docker Scout Dashboard, and CLI. Find out how in the overview guide.
-
Sign in to your Docker account with the
docker login
command or use the Sign in button in Docker Desktop. -
Next, enroll your organization with Docker Scout, using the
docker scout enroll
command.
console
$ docker scout enroll <ORG_NAME>
✓ Successfully enrolled organization <ORG_NAME> with Docker Scout Free
- Enable Docker Scout for your image repository with the
docker scout repo enable
command.
console
$ docker scout repo enable --org <ORG_NAME> <ORG_NAME>/scout-demo
Step 3: Analyze image vulnerabilities#
After building, use the docker scout
CLI command to see vulnerabilities
detected by Docker Scout.
The example application for this guide uses a vulnerable version of Express. The following command shows all CVEs affecting Express in the image you just built:
$ docker scout cves --only-package express
Docker Scout analyzes the image you built most recently by default, so there's no need to specify the name of the image in this case.
Learn more about the docker scout cves
command in the
CLI reference documentation
.
Step 4: Fix application vulnerabilities#
The fix suggested by Docker Scout is to update the underlying vulnerable express version to 4.17.3 or later.
- Update the
package.json
file with the new package version.
diff
"dependencies": {
- "express": "4.17.1"
+ "express": "4.17.3"
}
- Rebuild the image with a new tag and push it to your Docker Hub repository:
console
$ docker build --push -t <ORG_NAME>/scout-demo:v2 .
Now, viewing the latest tag of the image in Docker Desktop, the Docker Scout Dashboard, or CLI, you can see that you have fixed the vulnerability.
$ docker scout cves --only-package express
✓ Provenance obtained from attestation
✓ Image stored for indexing
✓ Indexed 79 packages
✓ No vulnerable package detected
## Overview
│ Analyzed Image
────────────────────┼───────────────────────────────────────────────────
Target │ mobywhale/scout-demo:v2
digest │ ef68417b2866
platform │ linux/arm64
provenance │ https://github.com/docker/scout-demo-service.git
│ 7c3a06793fc8f97961b4a40c73e0f7ed85501857
vulnerabilities │ 0C 0H 0M 0L
size │ 19 MB
packages │ 1
## Packages and Vulnerabilities
No vulnerable packages detected
Step 5: Evaluate policy compliance#
While inspecting vulnerabilities based on specific packages can be useful, it isn't the most effective way to improve your supply chain conduct.
Docker Scout also supports policy evaluation, a higher-level concept for detecting and fixing issues in your images. Policies are a set of customizable rules that let organizations track whether images are compliant with their supply chain requirements.
Because policy rules are specific to each organization,
you must specify which organization's policy you're evaluating against.
Use the docker scout config
command to configure your Docker organization.
$ docker scout config organization <ORG_NAME>
✓ Successfully set organization to <ORG_NAME>
Now you can run the quickview
command to get an overview
of the compliance status for the image you just built.
The image is evaluated against the default, out-of-the-box policies.
$ docker scout quickview
...
Policy status FAILED (2/6 policies met, 2 missing data)
Status │ Policy │ Results
─────────┼──────────────────────────────────────────────┼──────────────────────────────
✓ │ No copyleft licenses │ 0 packages
! │ Default non-root user │
! │ No fixable critical or high vulnerabilities │ 2C 16H 0M 0L
✓ │ No high-profile vulnerabilities │ 0C 0H 0M 0L
? │ No outdated base images │ No data
? │ Supply chain attestations │ No data
Exclamation marks in the status column indicate a violated policy. Question marks indicate that there isn't enough metadata to complete the evaluation. A check mark indicates compliance.
Step 6: Improve compliance#
The output of the quickview
command shows that there's room for improvement.
Some of the policies couldn't evaluate successfully (No data
)
because the image lacks provenance and SBOM attestations.
The image also failed the check on a few of the evaluations.
Policy evaluation does more than just check for vulnerabilities.
Take the Default non-root user
policy for example.
This policy helps improve runtime security by ensuring that
images aren't set to run as the root
superuser by default.
To address this policy violation, edit the Dockerfile by adding a USER
instruction, specifying a non-root user:
CMD ["node","/app/app.js"]
EXPOSE 3000
+ USER appuser
Additionally, to get a more complete policy evaluation result, your image should have SBOM and provenance attestations attached to it. Docker Scout uses the provenance attestations to determine how the image was built so that it can provide a better evaluation result.
Before you can build an image with attestations,
you must enable the containerd image store
(or create a custom builder using the docker-container
driver).
The classic image store doesn't support manifest lists,
which is how the provenance attestations are attached to an image.
Open Settings in Docker Desktop. Under the General section, make sure that the Use containerd for pulling and storing images option is checked. Note that changing image stores temporarily hides images and containers of the inactive image store until you switch back.
With the containerd image store enabled, rebuild the image with a new v3
tag.
This time, add the --provenance=true
and --sbom=true
flags.
$ docker build --provenance=true --sbom=true --push -t <ORG_NAME>/scout-demo:v3 .
Step 7: View in Dashboard#
After pushing the updated image with attestations, it's time to view the results through a different lens: the Docker Scout Dashboard.
- Open the Docker Scout Dashboard.
- Sign in with your Docker account.
- Select Images in the left-hand navigation.
The images page lists your Scout-enabled repositories. Select the image in the list to open the Image details sidebar. The sidebar shows a compliance overview for the last pushed tag of a repository.
[!NOTE]
If policy results haven't appeared yet, try refreshing the page. It might take a few minutes before the results appear if this is your first time using the Docker Scout Dashboard.
Inspect the No outdated base images policy.
This policy checks whether base images you use are up-to-date.
It currently has a non-compliant status,
because the example image uses an old version alpine
as a base image.
Select the View fix button next to the policy name for details about the violation, and recommendations on how to address it. In this case, the recommended action is to enable Docker Scout's GitHub integration, which helps keep your base images up-to-date automatically.
[!TIP]
You can't enable this integration for the demo app used in this guide. Feel free to push the code to a GitHub repository that you own, and try out the integration there!
Summary#
This quickstart guide has scratched the surface on some of the ways Docker Scout can support software supply chain management:
- How to enable Docker Scout for your repositories
- Analyzing images for vulnerabilities
- Policy and compliance
- Fixing vulnerabilities and improving compliance
What's next?#
There's lots more to discover, from third-party integrations, to policy customization, and runtime environment monitoring in real-time.
Check out the following sections: