media-types.md: clarify differences from Docker media types

OCI media types are slightly different from Docker ones,
e.g., Docker manifests must have `.mediaType` field while OCI may not have.
Also, OCI descriptors may have `.annotations` while Docker may not.

Also updates to compare the spec with Docker Image Spec v1.2, not v1.0.

OCI Image Spec v1 is more akin to Docker Image Spec v1.2 rather than v1.0,
which lacked content addressability.

See also https://github.com/moby/moby/blob/v20.10.1/image/spec/README.md for
differencces between Docker Image Spec v1.2 and v1.0.

Signed-off-by: Akihiro Suda <[email protected]>

Author: AkihiroSuda

config.md

@@ -183,6 +183,22 @@ Note: Any OPTIONAL field MAY also be set to null, which is equivalent to being a
 
     The field contains the system call signal that will be sent to the container to exit. The signal can be a signal name in the format `SIGNAME`, for instance `SIGKILL` or `SIGRTMIN+3`.
 
+  - **Memory** *integer*, OPTIONAL
+
+    This property is *reserved* for use, to [maintain compatibility](media-types.md#compatibility-matrix).
+
+  - **MemorySwap** *integer*, OPTIONAL
+
+    This property is *reserved* for use, to [maintain compatibility](media-types.md#compatibility-matrix).
+
+  - **CpuShares** *integer*, OPTIONAL
+
+    This property is *reserved* for use, to [maintain compatibility](media-types.md#compatibility-matrix).
+
+  - **Healthcheck** *object*, OPTIONAL
+
+    This property is *reserved* for use, to [maintain compatibility](media-types.md#compatibility-matrix).
+
 - **rootfs** *object*, REQUIRED
 
    The rootfs key references the layer content addresses used by the image.

media-types.md

@@ -38,25 +38,40 @@ This section shows where the OCI Image Specification is compatible with formats
 
 **Similar/related schema**
 
-- [application/vnd.docker.distribution.manifest.list.v2+json](https://github.com/docker/distribution/blob/master/docs/spec/manifest-v2-2.md#manifest-list) - mediaType is different
+- [application/vnd.docker.distribution.manifest.list.v2+json](https://github.com/distribution/distribution/blob/master/docs/spec/manifest-v2-2.md#manifest-list)
+  - `.mediaType`: only present in Docker, and reserved in OCI
+  - `.annotations`: only present in OCI
+  - `.[]manifests.annotations`: only present in OCI
+  - `.[]manifests.urls`: only present in OCI
 
 ### application/vnd.oci.image.manifest.v1+json
 
 **Similar/related schema**
 
-- [application/vnd.docker.distribution.manifest.v2+json](https://github.com/docker/distribution/blob/master/docs/spec/manifest-v2-2.md#image-manifest-field-descriptions)
+- [application/vnd.docker.distribution.manifest.v2+json](https://github.com/distribution/distribution/blob/master/docs/spec/manifest-v2-2.md#image-manifest-field-descriptions)
+  - `.mediaType`: only present in Docker, and reserved in OCI
+  - `.annotations`: only present in OCI
+  - `.config.annotations`: only present in OCI
+  - `.config.urls`: only present in OCI
+  - `.[]layers.annotations`: only present in OCI
 
 ### application/vnd.oci.image.layer.v1.tar+gzip
 
 **Interchangeable and fully compatible mime-types**
 
-- [application/vnd.docker.image.rootfs.diff.tar.gzip](https://github.com/docker/docker/blob/master/image/spec/v1.md#creating-an-image-filesystem-changeset)
+- [application/vnd.docker.image.rootfs.diff.tar.gzip](https://github.com/moby/moby/blob/v20.10.8/image/spec/v1.2.md#creating-an-image-filesystem-changeset)
 
 ### application/vnd.oci.image.config.v1+json
 
 **Similar/related schema**
 
-- [application/vnd.docker.container.image.v1+json](https://github.com/docker/docker/blob/master/image/spec/v1.md#image-json-description)
+- [application/vnd.docker.container.image.v1+json](https://github.com/moby/moby/blob/v20.10.8/image/spec/v1.2.md#image-json-description) (Docker Image Spec v1.2)
+  - `.config.Memory`: only present in Docker, and reserved in OCI
+  - `.config.MemorySwap`: only present in Docker, and reserved in OCI
+  - `.config.CpuShares`: only present in Docker, and reserved in OCI
+  - `.config.Healthcheck`: only present in Docker, and reserved in OCI
+
+`.config.StopSignal` and `.config.Labels` are accidentally undocumented in Docker Image Spec v1.2, but these fields are not OCI-specific concepts.
 
 ## Relations