Documentation
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Overview ¶
Package oci is a small read-only OCI Distribution v2 client. It pulls manifests and blobs anonymously or with the registry credentials of the Docker client configuration, through Basic or Bearer-token challenges, which is sufficient for fetching devcontainer features published as OCI artifacts (the "ghcr.io/devcontainers/features/*" namespace, for instance).
This client does not do content verification beyond digest matching, and is intentionally minimal — it's not a substitute for go-containerregistry or oras-go in production-grade tooling.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Client ¶
type Client struct {
HTTP *http.Client
// Auth supplies registry credentials. When nil, every registry is
// accessed anonymously.
Auth CredentialSource
// contains filtered or unexported fields
}
Client performs read operations against an OCI distribution registry.
func NewClient ¶
func NewClient() *Client
NewClient constructs a Client using sensible defaults. It reads registry credentials from the Docker client configuration.
func (*Client) FetchBlob ¶
FetchBlob streams a blob to the supplied writer. It verifies the digest before returning success. Errors name ref, not the digest, which can come from a manifest.
func (*Client) FetchImageConfig ¶
func (c *Client) FetchImageConfig(ref Reference, p Platform) (*ImageConfig, error)
FetchImageConfig returns the configuration of the image ref for platform p, following a multi-platform index to p's manifest.
func (*Client) FetchManifest ¶
FetchManifest fetches a manifest by reference, following indexes if needed by selecting the first child manifest. (For features, indexes are rare; when present we just take whatever is first.)
func (*Client) WithAuth ¶
func (c *Client) WithAuth(auth CredentialSource) *Client
WithAuth returns a client that reads registry credentials from auth and shares c's HTTP client. Its authorizations start empty, so that a token c obtained with its own credentials is never sent for auth. A nil c gives NewClient's HTTP client.
type CredentialSource ¶
type CredentialSource interface {
Credentials(host string) (registryauth.Credentials, error)
}
CredentialSource supplies the credentials for a registry host.
type Descriptor ¶
type Descriptor struct {
MediaType string `json:"mediaType"`
Digest string `json:"digest"`
Size int64 `json:"size"`
Annotations map[string]string `json:"annotations,omitempty"`
Platform *Platform `json:"platform,omitempty"`
}
Descriptor is the OCI content descriptor used by manifests.
type ImageConfig ¶
type ImageConfig struct {
Config struct {
Labels map[string]string `json:"Labels,omitempty"`
Entrypoint []string `json:"Entrypoint,omitempty"`
Cmd []string `json:"Cmd,omitempty"`
User string `json:"User,omitempty"`
Env []string `json:"Env,omitempty"`
} `json:"config"`
}
ImageConfig is the subset of an OCI image configuration this package reads.
type Index ¶
type Index struct {
SchemaVersion int `json:"schemaVersion"`
MediaType string `json:"mediaType"`
Manifests []Descriptor `json:"manifests"`
}
Index is a thin model of an OCI index / Docker manifest list.
type Manifest ¶
type Manifest struct {
SchemaVersion int `json:"schemaVersion"`
MediaType string `json:"mediaType"`
ArtifactType string `json:"artifactType,omitempty"`
Config Descriptor `json:"config"`
Layers []Descriptor `json:"layers"`
Annotations ManifestAnnot `json:"annotations,omitempty"`
}
Manifest is a thin model of an OCI image manifest.
type ManifestAnnot ¶
ManifestAnnot is the typed map for manifest-level annotations.
type Platform ¶
type Platform struct {
OS string `json:"os,omitempty"`
Architecture string `json:"architecture,omitempty"`
Variant string `json:"variant,omitempty"`
}
Platform is the OCI platform object found on index descriptors.
type Reference ¶
Reference is a parsed image reference of the form registry/repository:tag (or @digest).
func ParseReference ¶
ParseReference parses an OCI reference. If no registry is specified, docker.io is assumed (with an "library/" prefix for single-segment names, matching docker conventions).
Source Files