Ubuntu Manpage: buildah-commit - Create an image from a working container.

NAME

       buildah-commit - Create an image from a working container.

SYNOPSIS

       buildah commit [options] container [image]

DESCRIPTION

       Writes  a new image using the specified container's read-write layer and if it is based on
       an image, the layers of that image.   If  image  does  not  begin  with  a  registry  name
       component,  localhost will be added to the name.  If image is not provided, the image will
       have no name.  When an image has no name, the buildah images command will  display  <none>
       in the REPOSITORY and TAG columns.

       The  image value supports all transports from containers-transports(5). If no transport is
       specified, the containers-storage (i.e., local storage) transport is used.

RETURN VALUE

       The image ID of the image that was  created.   On  error,  1  is  returned  and  errno  is
       returned.

OPTIONS

--add-file source[:destination]

Read the contents of the file source and add it to the committed image as a file at
destination. If destination is not specified, the path of source will be used. The new
file will be owned by UID 0, GID 0, have 0644 permissions, and be given a current
timestamp unless the --timestamp option is also specified. This option can be specified
multiple times.

--authfile path

Path of the authentication file. Default is ${XDG_RUNTIME_DIR}/containers/auth.json. See
containers-auth.json(5) for more information. This file is created using buildah login.

If the authorization state is not found there, $HOME/.docker/config.json is checked, which
is set using docker login.

Note: You can also override the default path of the authentication file by setting the
REGISTRY_AUTH_FILE environment variable. export REGISTRY_AUTH_FILE=path

--cert-dir path

Use certificates at path (*.crt, *.cert, *.key) to connect to the registry. The default
certificates directory is /etc/containers/certs.d.

--change, -c "INSTRUCTION"

Apply the change to the committed image that would have been made if it had been built
using a Containerfile which included the specified instruction. This option can be
specified multiple times.

--config filename

Read a JSON-encoded version of an image configuration object from the specified file, and
merge the values from it with the configuration of the image being committed.

--creds creds

The [username[:password]] to use to authenticate with the registry if required. If one or
both values are not supplied, a command line prompt will appear and the value can be
entered. The password is entered without echo.

--cw options

Produce an image suitable for use as a confidential workload running in a trusted
execution environment (TEE) using krun (i.e., crun built with the libkrun feature enabled
and invoked as krun). Instead of the conventional contents, the root filesystem of the
image will contain an encrypted disk image and configuration information for krun.

The value for options is a comma-separated list of key=value pairs, supplying
configuration information which is needed for producing the additional data which will be
included in the container image.

Recognized keys are:

attestation_url: The location of a key broker / attestation server. If a value is
specified, the new image's workload ID, along with the passphrase used to encrypt the disk
image, will be registered with the server, and the server's location will be stored in the
container image. At run-time, krun is expected to contact the server to retrieve the
passphrase using the workload ID, which is also stored in the container image. If no
value is specified, a passphrase value must be specified.

cpus: The number of virtual CPUs which the image expects to be run with at run-time. If
not specified, a default value will be supplied.

firmware_library: The location of the libkrunfw-sev shared library. If not specified,
buildah checks for its presence in a number of hard-coded locations.

memory: The amount of memory which the image expects to be run with at run-time, as a
number of megabytes. If not specified, a default value will be supplied.

passphrase: The passphrase to use to encrypt the disk image which will be included in the
container image. If no value is specified, but an attestation_url value is specified, a
randomly-generated passphrase will be used. The authors recommend setting an
attestation_url but not a passphrase.

slop: Extra space to allocate for the disk image compared to the size of the container
image's contents, expressed either as a percentage (..%) or a size value (bytes, or larger
units if suffixes like KB or MB are present), or a sum of two or more such specifications
separated by "+". If not specified, buildah guesses that 25% more space than the contents
will be enough, but this option is provided in case its guess is wrong. If the specified
or computed size is less than 10 megabytes, it will be increased to 10 megabytes.

type: The type of trusted execution environment (TEE) which the image should be marked for
use with. Accepted values are "SEV" (AMD Secure Encrypted Virtualization - Encrypted
State) and "SNP" (AMD Secure Encrypted Virtualization - Secure Nested Paging). If not
specified, defaults to "SNP".

workload_id: A workload identifier which will be recorded in the container image, to be
used at run-time for retrieving the passphrase which was used to encrypt the disk image.
If not specified, a semi-random value will be derived from the base image's image ID.

--disable-compression, -D

Don't compress filesystem layers when building the image unless it is required by the
location where the image is being written. This is the default setting, because image
layers are compressed automatically when they are pushed to registries, and images being
written to local storage would only need to be decompressed again to be stored.
Compression can be forced in all cases by specifying --disable-compression=false.

--encrypt-layer layer(s)

Layer(s) to encrypt: 0-indexed layer indices with support for negative indexing (e.g. 0 is
the first layer, -1 is the last layer). If not defined, will encrypt all layers if
encryption-key flag is specified.

--encryption-key key

The [protocol:keyfile] specifies the encryption protocol, which can be JWE (RFC7516), PGP
(RFC4880), and PKCS7 (RFC2315) and the key material required for image encryption. For
instance, jwe:/path/to/key.pem or pgp:admin@example.com or pkcs7:/path/to/x509-file.

--format, -f [oci | docker]

Control the format for the image manifest and configuration data. Recognized formats
include oci (OCI image-spec v1.0, the default) and docker (version 2, using schema format
2 for the manifest).

Note: You can also override the default format by setting the BUILDAH_FORMAT environment
variable. export BUILDAH_FORMAT=docker

--identity-label bool-value

Adds default identity label io.buildah.version if set. (default true).

--iidfile ImageIDfile

Write the image ID to the file.

--manifest "listName"

Name of the manifest list to which the built image will be added. Creates the manifest
list if it does not exist. This option is useful for building multi architecture images.

--omit-history bool-value

Omit build history information in the built image. (default false).

This option is useful for the cases where end users explicitly want to set --omit-history
to omit the optional History from built images or when working with images built using
build tools that do not include History information in their images.

--pull

When the --pull flag is enabled or set explicitly to true (with --pull=true), attempt to
pull the latest versions of SBOM scanner images from the registries listed in
registries.conf if a local SBOM scanner image does not exist or the image in the registry
is newer than the one in local storage. Raise an error if the SBOM scanner image is not
in any listed registry and is not present locally.

If the flag is disabled (with --pull=false), do not pull SBOM scanner images from
registries, use only local versions. Raise an error if a SBOM scanner image is not present
locally.

If the pull flag is set to always (with --pull=always), pull SBOM scanner images from the
registries listed in registries.conf. Raise an error if a SBOM scanner image is not found
in the registries, even if an image with the same name is present locally.

If the pull flag is set to missing (with --pull=missing), pull SBOM scanner images only if
they could not be found in the local containers storage. Raise an error if no image could
be found and the pull fails.

If the pull flag is set to never (with --pull=never), do not pull SBOM scanner images from
registries, use only the local versions. Raise an error if the image is not present
locally.

--quiet, -q

When writing the output image, suppress progress output.

--rm Remove the working container and its contents after creating the image. Default
leaves the container and its content in place.

--sbom preset

Generate SBOMs (Software Bills Of Materials) for the output image by scanning the working
container and build contexts using the named combination of scanner image, scanner
commands, and merge strategy. Must be specified with one or more of --sbom-image-output,
--sbom-image-purl-output, --sbom-output, and --sbom-purl-output. Recognized presets, and
the set of options which they equate to:

• "syft", "syft-cyclonedx":
--sbom-scanner-image=ghcr.io/anchore/syft
--sbom-scanner-command="/syft scan -q dir:{ROOTFS} --output cyclonedx-
json={OUTPUT}"
--sbom-scanner-command="/syft scan -q dir:{CONTEXT} --output cyclonedx-
json={OUTPUT}"
--sbom-merge-strategy=merge-cyclonedx-by-component-name-and-version

• "syft-spdx":
--sbom-scanner-image=ghcr.io/anchore/syft
--sbom-scanner-command="/syft scan -q dir:{ROOTFS} --output spdx-json={OUTPUT}"
--sbom-scanner-command="/syft scan -q dir:{CONTEXT} --output spdx-json={OUTPUT}"
--sbom-merge-strategy=merge-spdx-by-package-name-and-versioninfo

• "trivy", "trivy-cyclonedx":
--sbom-scanner-image=ghcr.io/aquasecurity/trivy
--sbom-scanner-command="trivy filesystem -q {ROOTFS} --format cyclonedx --output
{OUTPUT}"
--sbom-scanner-command="trivy filesystem -q {CONTEXT} --format cyclonedx
--output {OUTPUT}"
--sbom-merge-strategy=merge-cyclonedx-by-component-name-and-version

• "trivy-spdx":
--sbom-scanner-image=ghcr.io/aquasecurity/trivy
--sbom-scanner-command="trivy filesystem -q {ROOTFS} --format spdx-json --output
{OUTPUT}"
--sbom-scanner-command="trivy filesystem -q {CONTEXT} --format spdx-json
--output {OUTPUT}"
--sbom-merge-strategy=merge-spdx-by-package-name-and-versioninfo

--sbom-image-output path

When generating SBOMs, store the generated SBOM in the specified path in the output image.
There is no default.

--sbom-image-purl-output path

When generating SBOMs, scan them for PURL (package URL
⟨https://github.com/package-url/purl-spec/blob/master/PURL-SPECIFICATION.rst⟩)
information, and save a list of found PURLs to the named file in the local filesystem.
There is no default.

--sbom-merge-strategy method

If more than one --sbom-scanner-command value is being used, use the specified method to
merge the output from later commands with output from earlier commands. Recognized values
include:

• cat
Concatenate the files.

• merge-cyclonedx-by-component-name-and-version
Merge the "component" fields of JSON documents, ignoring values from
documents when the combination of their "name" and "version" values is
already present. Documents are processed in the order in which they are
generated, which is the order in which the commands that generate them
were specified.

• merge-spdx-by-package-name-and-versioninfo
Merge the "package" fields of JSON documents, ignoring values from
documents when the combination of their "name" and "versionInfo" values is
already present. Documents are processed in the order in which they are
generated, which is the order in which the commands that generate them
were specified.

--sbom-output file

When generating SBOMs, store the generated SBOM in the named file on the local filesystem.
There is no default.

--sbom-purl-output file

--sbom-scanner-command image

Generate SBOMs by running the specified command from the scanner image. If multiple
commands are specified, they are run in the order in which they are specified. These text
substitutions are performed:
- {ROOTFS}
The root of the built image's filesystem, bind mounted.
- {CONTEXT}
The build context and additional build contexts, bind mounted.
- {OUTPUT}
The name of a temporary output file, to be read and merged with others or copied
elsewhere.

--sbom-scanner-image image

Generate SBOMs using the specified scanner image.

--sign-by fingerprint

Sign the new image using the GPG key that matches the specified fingerprint.

--squash

Squash all of the new image's layers (including those inherited from a base image) into a
single new layer.

--timestamp seconds

Set the create timestamp to seconds since epoch to allow for deterministic builds
(defaults to current time). By default, the created timestamp is changed and written into
the image manifest with every commit, causing the image's sha256 hash to be different even
if the sources are exactly the same otherwise. When --timestamp is set, the created
timestamp is always set to the time specified and therefore not changed, allowing the
image's sha256 to remain the same. All files committed to the layers of the image will be
created with the timestamp.

--tls-verify bool-value

Require HTTPS and verification of certificates when talking to container registries
(defaults to true). TLS verification cannot be used when talking to an insecure registry.

--unsetenv env

Unset environment variables from the final image.

EXAMPLE

       This example saves an image based on the container.
        buildah commit containerID newImageName

       This example saves an image named newImageName based on  the  container  and  removes  the
       working container.
        buildah commit --rm containerID newImageName

       This  example  commits  to  an  OCI  archive  file  named  /tmp/newImageName  based on the
       container.
        buildah commit containerID oci-archive:/tmp/newImageName

       This example saves an image with no name, removes the working container, and creates a new
       container using the image's ID.
        buildah from $(buildah commit --rm containerID)

       This example saves an image based on the container disabling compression.
        buildah commit --disable-compression containerID

       This  example  saves  an  image  named  newImageName  based  on  the  container  disabling
       compression.
        buildah commit --disable-compression containerID newImageName

       This example commits the container to the image on the local registry  while  turning  off
       tls verification.
        buildah commit --tls-verify=false containerID docker://localhost:5000/imageId

       This  example  commits  the container to the image on the local registry using credentials
       and certificates for authentication.
        buildah commit --cert-dir ~/auth  --tls-verify=true --creds=username:password containerID
       docker://localhost:5000/imageId

       This  example  commits  the container to the image on the local registry using credentials
       from the /tmp/auths/myauths.json file and certificates for authentication.
        buildah commit --authfile /tmp/auths/myauths.json  --cert-dir  ~/auth   --tls-verify=true
       --creds=username:password containerID docker://localhost:5000/imageName

       This  example saves an image based on the container, but stores dates based on epoch time.
       buildah commit --timestamp=0 containerID newImageName

   Building an multi-architecture image using the --manifest option (requires emulation software)
       #!/bin/sh
       build() {
            ctr=$(./bin/buildah from --arch $1 ubi8)
            ./bin/buildah run $ctr dnf install -y iputils
            ./bin/buildah commit --manifest ubi8ping $ctr
       }
       build arm
       build amd64
       build s390x

ENVIRONMENT

       BUILD_REGISTRY_SOURCES

       BUILD_REGISTRY_SOURCES, if set, is treated as  a  JSON  object  which  contains  lists  of
       registry    names    under    the    keys   insecureRegistries,   blockedRegistries,   and
       allowedRegistries.

       When committing an image, if the image is to be given a name, the portion of the name that
       corresponds  to  a registry is compared to the items in the blockedRegistries list, and if
       it matches any of them, the commit attempt is denied.  If  there  are  registries  in  the
       allowedRegistries  list,  and  the portion of the name that corresponds to the registry is
       not in the list, the commit attempt is denied.

       TMPDIR The TMPDIR environment variable allows the user to specify  where  temporary  files
       are stored while pulling and pushing images.  Defaults to '/var/tmp'.

FILES

       registries.conf (/etc/containers/registries.conf)

       registries.conf  is  the  configuration  file  which  specifies which container registries
       should be consulted when completing image names which do not include a registry or  domain
       portion.

       policy.json (/etc/containers/policy.json)

       Signature  policy  file.   This  defines  the trust policy for container images.  Controls
       which container registries can be used for image, and whether or not the tool should trust
       the images.