Red Hat Summit Red Hat SummitSupportKonsoleEntwicklerDemo startenKontakt

Dieser Inhalt ist in der von Ihnen ausgewählten Sprache nicht verfügbar.

Chapter 12. Using buildah-ns Tekton task

The buildah-ns Tekton task builds Open Container Initiative (OCI) images without requiring a container runtime daemon, such as the Docker daemon. The task uses buildah and applies user namespace isolation to provide enhanced security.

After a successful build, the task produces the following results:

  • The fully qualified image name
  • The SHA256 digest of the image

The buildah-ns task is functionally the same as the standard buildah Tekton task, but applies additional security mechanisms to improve container isolation at the kernel level.

12.1. Differences between buildah and buildah-ns tasks
Link kopieren

The buildah-ns task extends the standard buildah task with the following security-focused changes:

  • Task name: The task name is buildah-ns instead of buildah.

  • Annotations: The task includes security annotations that enable automatic user namespace mapping: 

    io.kubernetes.cri-o.userns-mode: "auto"
io.openshift.builder: "true"
  • Security model: User namespace separation improves privilege isolation. This limits the impact of container escape vulnerabilities.

12.2. Security model of the buildah-ns task
Link kopieren

The buildah-ns task uses user namespace isolation to separate privileges between containers and the host system.

When the task runs with namespace annotations, the system maps user IDs (UIDs) as follows:

  • Inside the container: Processes run as UID 0, which is displayed as the root user.
  • Outside the container: The same processes run as a nonzero UID on the host system.

This mapping lets container processes behave as root while restricting their host-level privileges.

User namespace isolation provides the following security advantages:

  • kernel-level isolation: Adds an extra isolation boundary between containers.
  • Reduced privilege exposure: Limits the impact of compromised workloads by running them as non-root users on the host.
  • Container escape protection: Helps mitigate potential vulnerabilities that allow escaping from the container runtime environment.

12.3. Workspaces, parameters, and results for the buildah-ns task
Link kopieren

The buildah-ns task requires a workspace and accepts several parameters to customize image builds. The task results contain information about the built image.

12.3.1. Workspace
Link kopieren

Expand
NameRequiredDescription

source

Yes

The build context for the container image. Typically has application source code and a Containerfile or Dockerfile.

12.3.2. Parameters
Link kopieren

Expand
NameTypeDefaultDescription

IMAGE

string

Required

Fully qualified name of the image to build, including tag.

CONTAINERFILE_PATH

string

Containerfile

Path to the container build file relative to the source workspace.

TLS_VERIFY

string

true

Verify TLS when pushing images. Red Hat recommends true.

VERBOSE

string

false

Enables verbose build output.

SUBDIRECTORY

string

.

Subdirectory in the workspace to use as the build context.

STORAGE_DRIVER

string

overlay

Storage driver for Buildah. Align with the cluster node configuration.

BUILD_EXTRA_ARGS

string

Empty

Additional flags for the Buildah build command.

PUSH_EXTRA_ARGS

string

Empty

Additional flags for the Buildah push command.

SKIP_PUSH

string

false

Set to true to skip pushing the image to the registry.

12.3.3. Results
Link kopieren

Expand
NameDescription

IMAGE_URL

Fully qualified name of the built image.

IMAGE_DIGEST

SHA256 digest of the built image.

12.4. Running the buildah-ns task
Link kopieren

You can run the buildah-ns task as part of a PipelineRun resource.

Procedure

  1. Create a YAML file that defines PipelineRun object:

    Example pipeline-run.yaml file

    apiVersion: tekton.dev/v1
kind: PipelineRun
metadata: {}
spec:
  pipelineRef:
    name: task-buildah-ns
  params:
    - name: IMAGE
      value: your-image-name
    - name: TLS_VERIFY
      value: true
    - name: VERBOSE
      value: false
  workspaces:
    - name: source
      persistentVolumeClaim:
        claimName: your-pvc-name

    value
    Replace your-image-name with the full name of the container image that you want to build.
    claimName

    Replace your-pvc-name with the name of the PersistentVolumeClaim (PVC) that stores the application source code.

    Note

    If the target container registry requires authentication, configure a Kubernetes secret for registry access and link it to the service account that runs the TaskRun or PipelineRun resources.

  2. Create the PipelineRun resource by applying the YAML file: 

    $ oc apply -f pipeline-run.yaml
Red Hat logoGithubredditYoutubeTwitter

Lernen

Testen, kaufen und verkaufen

Communitys

Über Red Hat Dokumentation

Wir helfen Red Hat Benutzern, mit unseren Produkten und Diensten innovativ zu sein und ihre Ziele zu erreichen – mit Inhalten, denen sie vertrauen können. Entdecken Sie unsere neuesten Updates.

Mehr Inklusion in Open Source

Red Hat hat sich verpflichtet, problematische Sprache in unserem Code, unserer Dokumentation und unseren Web-Eigenschaften zu ersetzen. Weitere Einzelheiten finden Sie in Red Hat Blog.

Über Red Hat

Wir liefern gehärtete Lösungen, die es Unternehmen leichter machen, plattform- und umgebungsübergreifend zu arbeiten, vom zentralen Rechenzentrum bis zum Netzwerkrand.

Theme

© 2026 Red HatNach oben