github.com/Prakhar-Agarwal-byte/moby@v0.0.0-20231027092010-a14e3e8ab87e/image/spec/README.md (about)

     1  # Docker Image Specification v1.
     2  
     3  This directory contains documents about Docker Image Specification v1.X.
     4  
     5  The Docker Image Specification is the image specification as used by the
     6  Docker Engine, and was used as foundation of the OCI image specification.
     7  
     8  The Docker Image Specification provides a superset of the OCI Image specification;
     9  it is OCI-compatible, but some extensions that are specific to the Docker
    10  Engine implementation.
    11  
    12  Refer to [spec.md](spec.md) for the current version of the Docker Image
    13  Specification, and the [OCI Image specification](https://github.com/opencontainers/image-spec/)
    14  for an in-depth specification of the OCI Image specs.
    15  
    16  The v1 file layout and manifests are no longer used in Moby and Docker, except in `docker save` and `docker load`.
    17  
    18  However, v1 Image JSON (`application/vnd.docker.container.image.v1+json`) has been still widely
    19  used and officially adopted in [V2 manifest](https://github.com/docker/distribution/blob/master/docs/spec/manifest-v2-2.md)
    20  and in [OCI Image Format Specification](https://github.com/opencontainers/image-spec).
    21  
    22  ## v1.X rough Changelog
    23  
    24  All 1.X versions are compatible with older ones.
    25  
    26  ### [v1.3](spec.md)
    27  
    28  * Implemented in Docker v25.0
    29  
    30  Changes:
    31  
    32  * `StartInterval` was added to the `Healthcheck` struct in the Image JSON
    33  
    34  ### [v1.2](https://github.com/moby/moby/blob/daa4618da826fb1de4fc2478d88196edbba49b2f/image/spec/v1.2.md)
    35  
    36  * Implemented in Docker v1.12 (July, 2016)
    37  * The official spec document was written in August 2016 ([#25750](https://github.com/moby/moby/pull/25750))
    38  
    39  Changes:
    40  
    41  * `Healthcheck` struct was added to Image JSON
    42  
    43  ### [v1.1](https://github.com/moby/moby/blob/daa4618da826fb1de4fc2478d88196edbba49b2f/image/spec/v1.1.md)
    44  
    45  * Implemented in Docker v1.10 (February, 2016)
    46  * The official spec document was written in April 2016 ([#22264](https://github.com/moby/moby/pull/22264))
    47  
    48  Changes:
    49  
    50  * IDs were made into SHA256 digest values rather than random values
    51  * Layer directory names were made into deterministic values rather than random ID values
    52  * `manifest.json` was added 
    53  
    54  ### [v1](https://github.com/moby/moby/blob/daa4618da826fb1de4fc2478d88196edbba49b2f/image/spec/v1.md)
    55  
    56  * The initial revision
    57  * The official spec document was written in late 2014 ([#9560](https://github.com/moby/moby/pull/9560)), but actual implementations had existed even earlier
    58  
    59  
    60  ## Related specifications
    61  
    62  * [Open Containers Initiative (OCI) Image Format Specification v1.0.0](https://github.com/opencontainers/image-spec/tree/v1.0.0)
    63  * [Docker Image Manifest Version 2, Schema 2](https://github.com/docker/distribution/blob/master/docs/spec/manifest-v2-2.md)
    64  * [Docker Image Manifest Version 2, Schema 1](https://github.com/docker/distribution/blob/master/docs/spec/manifest-v2-1.md) (*DEPRECATED*)
    65  * [Docker Registry HTTP API V2](https://docs.docker.com/registry/spec/api/)