Dockerfile Release Notes (Versions 1.6.0 to 1.4.0)

- The `ADD` instruction now supports [`--checksum` flag](/reference/dockerfile.md#verifying-a-remote-file-checksum-add---checksumchecksum-http-src-dest) to validate the contents of the remote URL contents ### Bug fixes and enhancements - Variable substitution now supports additional POSIX compatible variants without `:`. [moby/buildkit#3611](https://github.com/moby/buildkit/pull/3611) - Exported Windows images now contain OSVersion and OSFeatures values from base image. [moby/buildkit#3619](https://github.com/moby/buildkit/pull/3619) - Changed the permissions for Heredocs to 0644. [moby/buildkit#3992](https://github.com/moby/buildkit/pull/3992) ## 1.5.2 {{< release-date date="2023-02-14" >}} ### Bug fixes and enhancements - Fix building from Git reference that is missing branch name but contains a subdir - 386 platform image is now included in the release ## 1.5.1 {{< release-date date="2023-01-18" >}} ### Bug fixes and enhancements - Fix possible panic when warning conditions appear in multi-platform builds ## 1.5.0 (labs) {{< release-date date="2023-01-10" >}} {{% include "dockerfile-labs-channel.md" %}} ### New - `ADD` command now supports [`--checksum` flag](/reference/dockerfile.md#verifying-a-remote-file-checksum-add---checksumchecksum-http-src-dest) to validate the contents of the remote URL contents ## 1.5.0 {{< release-date date="2023-01-10" >}} ### New - `ADD` command can now [import files directly from Git URLs](/reference/dockerfile.md#adding-a-git-repository-add-git-ref-dir) ### Bug fixes and enhancements - Named contexts now support `oci-layout://` protocol for including images from local OCI layout structure - Dockerfile now supports secondary requests for listing all build targets or printing outline of accepted parameters for a specific build target - Dockerfile `#syntax` directive that redirects to an external frontend image now allows the directive to be also set with `//` comments or JSON. The file may also contain a shebang header - Named context can now be initialized with an empty scratch image - Named contexts can now be initialized with an SSH Git URL - Fix handling of `ONBUILD` when importing Schema1 images ## 1.4.3 {{< release-date date="2022-08-23" >}} ### Bug fixes and enhancements - Fix creation timestamp not getting reset when building image from `docker-image://` named context - Fix passing `--platform` flag of `FROM` command when loading `docker-image://` named context ## 1.4.2 {{< release-date date="2022-05-06" >}} ### Bug fixes and enhancements - Fix loading certain environment variables from an image passed with built context ## 1.4.1 {{< release-date date="2022-04-08" >}} ### Bug fixes and enhancements - Fix named context resolution for cross-compilation cases from input when input is built for a different platform ## 1.4.0 {{< release-date date="2022-03-09" >}} ### New - [`COPY --link` and `ADD --link`](/reference/dockerfile.md#copy---link) allow copying files with increased cache efficiency and rebase images without requiring them to be rebuilt. `--link` copies files to a separate layer and then uses new LLB MergeOp implementation to chain independent layers together - [Heredocs](/reference/dockerfile.md#here-documents) support have been promoted from labs channel to stable. This feature allows writing multiline inline scripts and files - Additional [named build contexts](/reference/cli/docker/buildx/build.md#build-context) can be passed to build to add or overwrite a stage or an image inside the build. A source for the context can be a local source, image, Git, or HTTP URL - [`BUILDKIT_SANDBOX_HOSTNAME` build-arg](/reference/dockerfile.md#buildkit-built-in-build-args) can be used to set the default hostname for the `RUN` steps ### Bug fixes and enhancements - When using a cross-compilation stage, the target platform for a step is now seen on progress output - Fix some cases where Heredocs incorrectly removed quotes from content

This section summarizes Dockerfile release notes from version 1.6.0 to 1.4.0. Highlights include the promotion of the `--checksum` flag for the `ADD` instruction to stable, enhancements to variable substitution, fixes for Windows image exports, and changes to Heredocs permissions in version 1.6.0. Subsequent versions include fixes for Git references, multi-platform builds, and the introduction of new features in the labs channel like the `--checksum` flag for `ADD` in version 1.5.0. Version 1.5.0 introduced direct Git URL imports and OCI layout support. Finally, version 1.4.0 introduces `COPY --link` and `ADD --link`, and promotes Heredocs support to stable, along with additional named build contexts and `BUILDKIT_SANDBOX_HOSTNAME` build-arg.