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What's New¶

v1.0.0 ¶

Convert a Dockerfile for stacker¶

A new stacker convert command performs a conversion of a Dockerfile into a stacker.yaml file. During the conversion, some variables from the Dockerfile may be exported to a substitution file that can be included in stacker build using the --substitute-file <filename> command option.

The conversion is a best-effort process and may not be successful in all cases.

Publish specific images¶

By default, the stacker publish command pushes all images in a stacker.yaml file. Using a new command option, --image <value>, you can explicitly specify which images are to be published. This command option can be specified multiple times, selecting each image to be included. In either case, images configured with build-only: true are not published.

Specify a single working directory¶

A new stacker command option, --work-dir, sets the working directory for stacker's cache, OCI output, and rootfs output. The existing command options --stacker-dir, --oci-dir, and --roots-dir can then be omitted or used to override the --work-dir setting.

Import contents when no shell exists in the base image¶

Import directives can include destination paths. This feature is useful to simplify run section scripts, and for when images are built without a base image. With no base image, there is no shell to run the script in a run section. Prior to this change, a run: section was required to invoke a shell and to explicitly copy files to be imported into the image. For example, you can now write a directive such as the following, with no run: section:
```
test:
  from:
    type: scratch
  imports:
    - path: test_file
      dest: /files/
    - path: test_file2
      dest: /file2
```

Generate SBOMs during the build¶

Changes added in OCI Distribution Spec v1.1.0 and OCI Image Spec v1.1.0 (summarized here) allow arbitrary artifact types and references. These changes support software supply chain use cases such as SBOMs.
For a demonstration of an OCI artifacts workflow that generates an SBOM, see Software Provenance Workflow Using OCI Artifacts.

Report kernel version and fs type¶

The stacker check command now reports this information.

Build improvements¶

v0.40.1 ¶

Support for `scratch`¶

Prior to v0.40.1, stacker did not support empty root filesystems to be used as a base container image. The support has now been added which can be used to host statically built binaries.

Support for `import`ing content into container image¶

Prior to v0.40.1, copying content into a scratch image permanently involved bind mounting a shell such as busybox and invoking appropriate commands using the run directive. Now the import directive allows for the dest option to achieve the same.

Publish with substitutions specified in a file¶

Using a new build command option, substitute-file <value>, you can now declare variable substitutions in a file instead of the command line. The substitution file uses a 'FOO: bar' key-value yaml format to declare substitutions.

Some `squashfs` improvements¶

While building squashfs layers, use squashfuse_ll if available which is faster.

Last update: April 11, 2024