opencontainers/image-spec

Features

• Container Image Layering - Standardizes the structure of container images using filesystem layering to ensure cross-tool interoperability.
• Container Image Distribution - Establishes the standardized rules for structuring image blobs and manifests for consistent transfer between registries and clients.
• Layered Filesystems - Organize a root filesystem as an ordered collection of archives recording additions and deletions.
• Container Image Formats - Standardizes the structure of software containers to ensure interoperability across different build tools and runtimes.
• Content Descriptors - Provides a system to identify external components using media types and digests to ensure content integrity.
• Content-Addressable Storage - Implements a content-addressable storage model using cryptographic digests to uniquely identify and deduplicate image components.
• Filesystem Layer Serialization - Defines how filesystem additions and removals are packaged into archive blobs for distribution.
• Content Immutability - Ensures that image layers and manifests remain unchanged across registries to maintain data integrity.
• Verifiable Data Retrieval - Validates retrieved data against cryptographic hashes and byte sizes to detect corruption from untrusted sources.
• Content Identifiers - Implements standards for generating unique content identifiers using cryptographic hashes to enable content-addressable storage.
• Configuration Schemas - Provides a JSON-based specification for defining execution metadata like entrypoints and environment variables.
• Manifest Resolution - Implements mechanisms to traverse indices and manifests to locate specific image configurations and filesystem layers.
• Container Image Specifications - Provides the standardized format for container images that ensures interoperability between different build tools and runtimes.
• Multi-Architecture Manifests - Implements image indices to map a single reference to multiple manifests for different operating systems and architectures.
• Runtime Configurations - Defines the execution metadata and filesystem layout required to launch applications from stored images.
• Image Index Variants - Organizes multiple manifests into a single index to support different platforms or attributes for the same image.
• Image Execution Metadata - Saves runtime configurations like commands and environment variables to launch applications on a target platform.
• Whiteout Processing - Reconstructs a filesystem by layering archives and processing whiteout markers to remove files from lower layers.
• Media Type Identification - Assigns standardized media types to manifests and layers to ensure consistent resource identification.
• Multi-Architecture Image Indexes - Uses image indices to map a single image reference to multiple platform-specific manifests for different architectures and operating systems.
• Multi-Platform Image Indices - Connect a high-level index to specific manifests based on target operating systems and architectures.
• Runtime Specification Mapping - Translates image blobs into runtime specifications by mapping environment variables and entrypoints to the runtime layout.
• Container Image Standards - Defines a universal format for container images to ensure they work across different build tools and runtimes.
• Layout Specifications - Defines a standardized directory layout for structuring blobs and references across transport mechanisms.
• Content-Addressable Authenticity - Uses content-addressable identities and hashes to ensure downloaded image components are untampered.
• Blob Hashing - Uses cryptographic hashing to verify that stored binary blobs match their expected identifiers.
• Container Registry - Provides a consistent way to store and transfer image layers and manifests across different registry implementations.
• Content Descriptors - Provides a descriptor-based mechanism to identify and validate remote image components before they are downloaded.
• Application Parameter Configurators - Defines runtime execution parameters such as entrypoints and environment variables within a JSON configuration.
• Image Resource Manifests - Employs JSON manifests to map an image configuration to its specific set of filesystem layers and media types.
• Serialization Interoperability Rules - Enforces strict JSON UTF-8 encoding and number precision to maintain interoperability across different runtime implementations.
• UTF-8 Sequence Validation - Validates byte sequences to ensure strict adherence to UTF-8 standards during configuration serialization.
• Artifact Packaging Tools - Bundles non-container artifacts using standard manifests and custom media types for distribution.
• Generic Artifact Packaging - Allows wrapping generic content into a standardized manifest using custom artifact types and configuration blobs.
• Container Image Metadata - Allows the attachment of custom key-value pairs for authorship and licensing within image manifests.
• Runtime Bundle Generation - Provides the mechanism to combine manifests and layers into a standardized runtime specification.
• Generic Artifact Packaging - Provides a flexible packaging format to bundle non-container artifacts using custom media types.
• Image to Runtime Translation - Defines how to translate image configurations and layouts into bundles suitable for execution by a runtime.
• Manifest-Based Packaging - Uses a flexible manifest structure to bundle non-container content using custom media types and configuration blobs.
• Layer Chain Identification - Associates unique chain identifiers with stacks of layers to identify the result of series changesets.
• Schema-Based Blob Validation - Checks the internal integrity and correctness of image data using schema-based validation.

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