proto/manifest.proto

syntax = "proto3";

package proto;
option go_package = "github.com/containerd/continuity/proto;proto";

// Manifest specifies the entries in a container bundle, keyed and sorted by
// path.
message Manifest {
    repeated Resource resource = 1;
}

message Resource {
    // Path specifies the path from the bundle root. If more than one
    // path is present, the entry may represent a hardlink, rather than using
    // a link target. The path format is operating system specific.
    repeated string path = 1;

    // NOTE(stevvooe): Need to define clear precedence for user/group/uid/gid precedence.

    // Uid specifies the user id for the resource.
    int64 uid = 2;

    // Gid specifies the group id for the resource.
    int64 gid = 3;

    // user and group are not currently used but their field numbers have been
    // reserved for future use. As such, they are marked as deprecated.
    string user = 4 [deprecated=true]; // "deprecated" stands for "reserved" here
    string group = 5 [deprecated=true]; // "deprecated" stands for "reserved" here

    // Mode defines the file mode and permissions. We've used the same
    // bit-packing from Go's os package,
    // https://golang.org/pkg/os/#FileMode, since they've done the work of
    // creating a cross-platform layout.
    uint32 mode = 6;

    // NOTE(stevvooe): Beyond here, we start defining type specific fields.

    // Size specifies the size in bytes of the resource. This is only valid
    // for regular files.
    uint64 size = 7;

    // Digest specifies the content digest of the target file. Only valid for
    // regular files. The strings are formatted in OCI style, i.e. <alg>:<encoded>.
    // For detailed information about the format, please refer to OCI Image Spec:
    // https://github.com/opencontainers/image-spec/blob/master/descriptor.md#digests-and-verification
    // The digests are sorted in lexical order and implementations may choose
    // which algorithms they prefer.
    repeated string digest = 8;

    // Target defines the target of a hard or soft link. Absolute links start
    // with a slash and specify the resource relative to the bundle root.
    // Relative links do not start with a slash and are relative to the
    // resource path.
    string target = 9;

    // Major specifies the major device number for character and block devices.
    uint64 major = 10;

    // Minor specifies the minor device number for character and block devices.
    uint64 minor = 11;

    // Xattr provides storage for extended attributes for the target resource.
    repeated XAttr xattr = 12;

    // Ads stores one or more alternate data streams for the target resource.
    repeated ADSEntry ads = 13;

}

// XAttr encodes extended attributes for a resource.
message XAttr {
    // Name specifies the attribute name.
    string name = 1;

    // Data specifies the associated data for the attribute.
    bytes data = 2;
}

// ADSEntry encodes information for a Windows Alternate Data Stream.
message ADSEntry {
    // Name specifices the stream name.
    string name = 1;

    // Data specifies the stream data.
    // See also the description about the digest below.
    bytes data = 2;

    // Digest is a CAS representation of the stream data.
    //
    // At least one of data or digest MUST be specified, and either one of them
    // SHOULD be specified.
    //
    // How to access the actual data using the digest is implementation-specific,
    // and implementations can choose not to implement digest.
    // So, digest SHOULD be used only when the stream data is large.
    string digest = 3;
}