24 KiB
type | stage | group | info |
---|---|---|---|
reference, howto | Defend | Container Security | To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#designated-technical-writers |
Container Scanning (ULTIMATE)
Introduced in GitLab Ultimate 10.4.
Your application's Docker image may itself be based on Docker images that contain known vulnerabilities. By including an extra job in your pipeline that scans for those vulnerabilities and displays them in a merge request, you can use GitLab to audit your Docker-based apps. By default, container scanning in GitLab is based on Clair and Klar, which are open-source tools for vulnerability static analysis in containers. GitLab's Klar analyzer scans the containers and serves as a wrapper for Clair.
To integrate security scanners other than Clair and Klar into GitLab, see Security scanner integration.
You can enable container scanning by doing one of the following:
- Include the CI job in your existing
.gitlab-ci.yml
file. - Implicitly use Auto Container Scanning provided by Auto DevOps.
GitLab compares the found vulnerabilities between the source and target branches, and shows the information directly in the merge request.
Requirements
To enable container scanning in your pipeline, you need the following:
-
GitLab Runner with the
docker
orkubernetes
executor. -
Docker
18.09.03
or higher installed on the same computer as the runner. If you're using the shared runners on GitLab.com, then this is already the case. -
Build and push your Docker image to your project's container registry. The name of the Docker image should use the following predefined environment variables:
$CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG:$CI_COMMIT_SHA
You can use these directly in your
.gitlab-ci.yml
file:build: image: docker:19.03.12 stage: build services: - docker:19.03.12-dind variables: IMAGE_TAG: $CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG:$CI_COMMIT_SHA script: - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY - docker build -t $IMAGE_TAG . - docker push $IMAGE_TAG
Configuration
How you enable container scanning depends on your GitLab version:
- GitLab 11.9 and later: Include the
Container-Scanning.gitlab-ci.yml
template that comes with your GitLab installation. - GitLab versions earlier than 11.9: Copy and use the job from the
Container-Scanning.gitlab-ci.yml
template.
To include the Container-Scanning.gitlab-ci.yml
template (GitLab 11.9 and later), add the
following to your .gitlab-ci.yml
file:
include:
- template: Container-Scanning.gitlab-ci.yml
The included template:
- Creates a
container_scanning
job in your CI/CD pipeline. - Pulls the built Docker image from your project's container registry (see requirements) and scans it for possible vulnerabilities.
GitLab saves the results as a Container Scanning report artifact that you can download and analyze later. When downloading, you always receive the most-recent artifact.
The following is a sample .gitlab-ci.yml
that builds your Docker image, pushes it to the container
registry, and scans the containers:
variables:
DOCKER_DRIVER: overlay2
stages:
- build
- test
build:
image: docker:stable
stage: build
services:
- docker:19.03.12-dind
variables:
IMAGE: $CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG:$CI_COMMIT_SHA
script:
- docker info
- docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
- docker build -t $IMAGE .
- docker push $IMAGE
include:
- template: Container-Scanning.gitlab-ci.yml
Customizing the container scanning settings
There may be cases where you want to customize how GitLab scans your containers. For example, you
may want to enable more verbose output from Clair or Klar, access a Docker registry that requires
authentication, and more. To change such settings, use the variables
parameter in your .gitlab-ci.yml
to set environment variables.
The environment variables you set in your .gitlab-ci.yml
overwrite those in
Container-Scanning.gitlab-ci.yml
.
This example includes the container scanning template and
enables verbose output from Clair by setting the CLAIR_OUTPUT
environment variable to High
:
include:
- template: Container-Scanning.gitlab-ci.yml
variables:
CLAIR_OUTPUT: High
Available variables
You can configure container scanning by using the following environment variables:
Environment Variable | Default | Description |
---|---|---|
ADDITIONAL_CA_CERT_BUNDLE |
"" |
Bundle of CA certs that you want to trust. |
CLAIR_DB_CONNECTION_STRING |
postgresql://postgres:password@clair-vulnerabilities-db:5432/postgres?sslmode=disable&statement_timeout=60000 |
This variable represents the connection string to the PostgreSQL server hosting the vulnerabilities definitions database and shouldn't be changed unless you're running the image locally as described in the Running the standalone container scanning tool section. The host value for the connection string must match the alias value of the Container-Scanning.gitlab-ci.yml template file, which defaults to clair-vulnerabilities-db . |
CLAIR_DB_IMAGE |
arminc/clair-db:latest |
The Docker image name and tag for the PostgreSQL server hosting the vulnerabilities definitions. It can be useful to override this value with a specific version, for example, to provide a consistent set of vulnerabilities for integration testing purposes, or to refer to a locally hosted vulnerabilities database for an on-premise offline installation. |
CLAIR_DB_IMAGE_TAG |
latest |
(DEPRECATED - use CLAIR_DB_IMAGE instead) The Docker image tag for the PostgreSQL server hosting the vulnerabilities definitions. It can be useful to override this value with a specific version, for example, to provide a consistent set of vulnerabilities for integration testing purposes. |
CLAIR_OUTPUT |
Unknown |
Severity level threshold. Vulnerabilities with severity level higher than or equal to this threshold are outputted. Supported levels are Unknown , Negligible , Low , Medium , High , Critical and Defcon1 . |
CLAIR_TRACE |
"false" |
Set to true to enable more verbose output from the clair server process. |
CLAIR_VULNERABILITIES_DB_URL |
clair-vulnerabilities-db |
(DEPRECATED - use CLAIR_DB_CONNECTION_STRING instead) This variable is explicitly set in the services section of the Container-Scanning.gitlab-ci.yml file and defaults to clair-vulnerabilities-db . This value represents the address that the PostgreSQL server hosting the vulnerabilities definitions is running on and shouldn't be changed unless you're running the image locally as described in the Running the standalone container scanning tool section. |
CI_APPLICATION_REPOSITORY |
$CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG |
Docker repository URL for the image to be scanned. |
CI_APPLICATION_TAG |
$CI_COMMIT_SHA |
Docker repository tag for the image to be scanned. |
DOCKER_INSECURE |
"false" |
Allow Klar to access secure Docker registries using HTTPS with bad (or self-signed) SSL certificates. |
DOCKER_PASSWORD |
$CI_REGISTRY_PASSWORD |
Password for accessing a Docker registry requiring authentication. |
DOCKER_USER |
$CI_REGISTRY_USER |
Username for accessing a Docker registry requiring authentication. |
DOCKERFILE_PATH |
Dockerfile |
The path to the Dockerfile to be used for generating remediations. By default, the scanner looks for a file named Dockerfile in the root directory of the project, so this variable should only be configured if your Dockerfile is in a non-standard location, such as a subdirectory. See Solutions for vulnerabilities for more details. |
KLAR_TRACE |
"false" |
Set to true to enable more verbose output from klar. |
REGISTRY_INSECURE |
"false" |
Allow Klar to access insecure registries (HTTP only). Should only be set to true when testing the image locally. |
SECURE_ANALYZERS_PREFIX |
"registry.gitlab.com/gitlab-org/security-products/analyzers" |
Set the Docker registry base address from which to download the analyzer. |
SECURE_LOG_LEVEL |
info |
Set the minimum logging level. Messages of this logging level or higher are output. From highest to lowest severity, the logging levels are: fatal , error , warn , info , debug . Introduced in GitLab 13.1. |
Overriding the container scanning template
If you want to override the job definition (for example, to change properties like variables
), you
must declare a container_scanning
job after the template inclusion, and then
specify any additional keys. For example:
include:
- template: Container-Scanning.gitlab-ci.yml
container_scanning:
variables:
GIT_STRATEGY: fetch
CAUTION: Deprecated:
GitLab 13.0 and later doesn't support only
and except
.
When overriding the template, you must use rules
instead.
Vulnerability allowlisting
To allowlist specific vulnerabilities, follow these steps:
- Set
GIT_STRATEGY: fetch
in your.gitlab-ci.yml
file by following the instructions in overriding the container scanning template. - Define the allowlisted vulnerabilities in a YAML file named
vulnerability-allowlist.yml
. This must use the format described in the allowlist example file. - Add the
vulnerability-allowlist.yml
file to your project's Git repository.
Running container scanning in an offline environment
For self-managed GitLab instances in an environment with limited, restricted, or intermittent access to external resources through the internet, some adjustments are required for the container scanning job to successfully run. For more information, see Offline environments.
Requirements for offline container Scanning
To use container scanning in an offline environment, you need:
- GitLab Runner with the
docker
orkubernetes
executor. - To configure a local Docker container registry with copies of the container scanning analyzer images, found in the container scanning container registry.
Note that GitLab Runner has a default pull policy
of always
,
meaning the runner tries to pull Docker images from the GitLab container registry even if a local
copy is available. The GitLab Runner pull_policy
can be set to if-not-present
in an offline environment if you prefer using only locally available Docker images. However, we
recommend keeping the pull policy setting to always
if not in an offline environment, as this
enables the use of updated scanners in your CI/CD pipelines.
Support for Custom Certificate Authorities
Support for custom certificate authorities was introduced in the following versions:
Analyzer | Version |
---|---|
klar |
v2.3.0 |
Make GitLab container scanning analyzer images available inside your Docker registry
For container scanning, import the following default images from registry.gitlab.com
into your
local Docker container registry:
registry.gitlab.com/gitlab-org/security-products/analyzers/klar
https://hub.docker.com/r/arminc/clair-db
The process for importing Docker images into a local offline Docker registry depends on your network security policy. Please consult your IT staff to find an accepted and approved process by which you can import or temporarily access external resources. Note that these scanners are updated periodically with new definitions, so consider if you are able to make periodic updates yourself.
For more information, see the specific steps on how to update an image with a pipeline.
For details on saving and transporting Docker images as a file, see Docker's documentation on
docker save
, docker load
,
docker export
, and docker import
.
Set container scanning CI job variables to use local container scanner analyzers
-
Override the container scanning template in your
.gitlab-ci.yml
file to refer to the Docker images hosted on your local Docker container registry:include: - template: Container-Scanning.gitlab-ci.yml container_scanning: image: $CI_REGISTRY/namespace/gitlab-klar-analyzer variables: CLAIR_DB_IMAGE: $CI_REGISTRY/namespace/clair-vulnerabilities-db
-
If your local Docker container registry is running securely over
HTTPS
, but you're using a self-signed certificate, then you must setDOCKER_INSECURE: "true"
in the abovecontainer_scanning
section of your.gitlab-ci.yml
.
Automating container scanning vulnerability database updates with a pipeline
It can be worthwhile to set up a scheduled pipeline to
build a new version of the vulnerabilities database on a preset schedule. Automating
this with a pipeline means you won't have to do it manually each time. You can use the following
.gitlab-yml.ci
as a template:
image: docker:stable
stages:
- build
build_latest_vulnerabilities:
stage: build
services:
- docker:19.03.12-dind
script:
- docker pull arminc/clair-db:latest
- docker tag arminc/clair-db:latest $CI_REGISTRY/namespace/clair-vulnerabilities-db
- docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
- docker push $CI_REGISTRY/namespace/clair-vulnerabilities-db
The above template works for a GitLab Docker registry running on a local installation, however, if you're using a non-GitLab Docker registry, you'll need to change the $CI_REGISTRY
value and the docker login
credentials to match the details of your local registry.
Running the standalone container scanning tool
It's possible to run the GitLab container scanning tool against a Docker container without needing to run it within the context of a CI job. To scan an image directly, follow these steps:
-
Run Docker Desktop or Docker Machine.
-
Run the latest prefilled vulnerabilities database Docker image:
docker run -p 5432:5432 -d --name clair-db arminc/clair-db:latest
-
Configure an environment variable to point to your local machine's IP address (or insert your IP address instead of the
LOCAL_MACHINE_IP_ADDRESS
variable in theCLAIR_DB_CONNECTION_STRING
in the next step):export LOCAL_MACHINE_IP_ADDRESS=your.local.ip.address
-
Run the analyzer's Docker image, passing the image and tag you want to analyze in the
CI_APPLICATION_REPOSITORY
andCI_APPLICATION_TAG
environment variables:docker run \ --interactive --rm \ --volume "$PWD":/tmp/app \ -e CI_PROJECT_DIR=/tmp/app \ -e CLAIR_DB_CONNECTION_STRING="postgresql://postgres:password@${LOCAL_MACHINE_IP_ADDRESS}:5432/postgres?sslmode=disable&statement_timeout=60000" \ -e CI_APPLICATION_REPOSITORY=registry.gitlab.com/gitlab-org/security-products/dast/webgoat-8.0@sha256 \ -e CI_APPLICATION_TAG=bc09fe2e0721dfaeee79364115aeedf2174cce0947b9ae5fe7c33312ee019a4e \ registry.gitlab.com/gitlab-org/security-products/analyzers/klar
The results are stored in gl-container-scanning-report.json
.
Reports JSON format
The container scanning tool emits a JSON report file. For more information, see the schema for this report.
Here's an example container scanning report:
{
"version": "2.3",
"vulnerabilities": [
{
"id": "ac0997ad-1006-4c81-81fb-ee2bbe6e78e3",
"category": "container_scanning",
"message": "CVE-2019-3462 in apt",
"description": "Incorrect sanitation of the 302 redirect field in HTTP transport method of apt versions 1.4.8 and earlier can lead to content injection by a MITM attacker, potentially leading to remote code execution on the target machine.",
"severity": "High",
"confidence": "Unknown",
"solution": "Upgrade apt from 1.4.8 to 1.4.9",
"scanner": {
"id": "klar",
"name": "klar"
},
"location": {
"dependency": {
"package": {
"name": "apt"
},
"version": "1.4.8"
},
"operating_system": "debian:9",
"image": "registry.gitlab.com/gitlab-org/security-products/dast/webgoat-8.0@sha256:bc09fe2e0721dfaeee79364115aeedf2174cce0947b9ae5fe7c33312ee019a4e"
},
"identifiers": [
{
"type": "cve",
"name": "CVE-2019-3462",
"value": "CVE-2019-3462",
"url": "https://security-tracker.debian.org/tracker/CVE-2019-3462"
}
],
"links": [
{
"url": "https://security-tracker.debian.org/tracker/CVE-2019-3462"
}
]
}
],
"remediations": [
{
"fixes": [
{
"id": "c0997ad-1006-4c81-81fb-ee2bbe6e78e3"
}
],
"summary": "Upgrade apt from 1.4.8 to 1.4.9",
"diff": "YXB0LWdldCB1cGRhdGUgJiYgYXB0LWdldCB1cGdyYWRlIC15IGFwdA=="
}
]
}
Security Dashboard
The Security Dashboard shows you an overview of all the security vulnerabilities in your groups, projects and pipelines.
Vulnerabilities database update
For more information about the vulnerabilities database update, check the maintenance table.
Interacting with the vulnerabilities
After a vulnerability is found, you can interact with it.
Solutions for vulnerabilities (auto-remediation)
Some vulnerabilities can be fixed by applying the solution that GitLab automatically generates.
To enable remediation support, the scanning tool must have access to the Dockerfile
specified by
the DOCKERFILE_PATH
environment variable. To ensure that the scanning tool
has access to this
file, it's necessary to set GIT_STRATEGY: fetch
in
your .gitlab-ci.yml
file by following the instructions described in this document's
overriding the container scanning template section.
Read more about the solutions for vulnerabilities.
Troubleshooting
docker: Error response from daemon: failed to copy xattrs
When the runner uses the docker
executor and NFS is used
(for example, /var/lib/docker
is on an NFS mount), container scanning might fail with
an error like the following:
docker: Error response from daemon: failed to copy xattrs: failed to set xattr "security.selinux" on /path/to/file: operation not supported.
This is a result of a bug in Docker which is now fixed.
To prevent the error, ensure the Docker version that the runner is using is
18.09.03
or higher. For more information, see
issue #10241.
Getting warning message gl-container-scanning-report.json: no matching files
For information on this, see the general Application Security troubleshooting section.