Red Hat Summit Red Hat SummitSupportConsoleDevelopersStart a trialContact

Chapter 5. Best practices for running containers using local sources

You can access content hosted in an internal registry that requires a custom Transport Layer Security (TLS) root certificate, when running RHEL bootc images.

There are two options available to install content to a container by using only local resources:

  • Bind mounts: Use for example -v /etc/pki:/etc/pki to override the container’s store with the host’s.
  • Derived image: Create a new container image with your custom certificates by building it using a Containerfile.

You can use the same techniques to run a bootc-image-builder container or a bootc container when appropriate.

5.1. Importing custom certificate to a container by using bind mounts

Use bound mounts to override the container’s store with the host’s.

Procedure

  • Run bootc-image-builder and use a bind mount, for example -v /etc/pki:/etc/pki, to override the container’s store with the host’s: 

    # podman run \
  --rm \
  -it \
  --privileged \
  --pull=newer \
  --security-opt label=type:unconfined_t \
  -v $(pwd)/output:/output \
  -v /etc/pki:/etc/pki \
  registry.redhat.io/rhel10/bootc-image-builder:latest \
  --type iso \
  --config /config.toml \
  quay.io/<namespace>/<image>:<tag>
    Copy to Clipboard

Verification

  • The disk image build process should now be able to access internal certificates.

5.2. Importing custom certificates to an image by using Containerfile

Include instructions to install custom certificate roots with a Containerfile.

Procedure

  1. Create a Containerfile: 

    FROM <internal_repository>/<image>
# Add certificate to the input set of anchors
COPY additional-certificate-root.pem /etc/pki/ca-trust/source/anchors
RUN update-ca-trust
    Copy to Clipboard

  2. Build the custom image: 

    # podman build -t <your_image> .
    Copy to Clipboard

  3. Run the <your_image>: 

    # podman run -it --rm <your_image>
    Copy to Clipboard

Verification

  • Verify your certificate is in the generated merged store: 

    # cat etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem
...
    Copy to Clipboard
Back to top
Red Hat logoGithubredditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust. Explore our recent updates.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Theme

© 2025 Red Hat