kubernetes/pkg/kubelet/api/v1alpha1/runtime/api.proto

// To regenerate api.pb.go run hack/update-generated-runtime.sh
syntax = 'proto2';

package runtime;

// Runtime service defines the public APIs for remote container runtimes
service RuntimeService {
    // Version returns the runtime name, runtime version, and runtime API version.
    rpc Version(VersionRequest) returns (VersionResponse) {}

    // RunPodSandbox creates and starts a pod-level sandbox. Runtimes must ensure
    // the sandbox is in the ready state on success.
    rpc RunPodSandbox(RunPodSandboxRequest) returns (RunPodSandboxResponse) {}
    // StopPodSandbox stops any running process that is part of the sandbox and
    // reclaims network resources (e.g., IP addresses) allocated to the sandbox.
    // If there are any running containers in the sandbox, they must be forcibly
    // terminated.
    // This call is idempotent, and must not return an error if all relevant
    // resources have already been reclaimed. kubelet will call StopPodSandbox
    // at least once before calling RemovePodSandbox. It will also attempt to
    // reclaim resources eagerly, as soon as a sandbox is not needed. Hence,
    // multiple StopPodSandbox calls are expected.
    rpc StopPodSandbox(StopPodSandboxRequest) returns (StopPodSandboxResponse) {}
    // RemovePodSandbox removes the sandbox. If there are any running containers
    // in the sandbox, they must be forcibly terminated and removed.
    // This call is idempotent, and must not return an error if the sandbox has
    // already been removed.
    rpc RemovePodSandbox(RemovePodSandboxRequest) returns (RemovePodSandboxResponse) {}
    // PodSandboxStatus returns the status of the PodSandbox.
    rpc PodSandboxStatus(PodSandboxStatusRequest) returns (PodSandboxStatusResponse) {}
    // ListPodSandbox returns a list of PodSandboxes.
    rpc ListPodSandbox(ListPodSandboxRequest) returns (ListPodSandboxResponse) {}

    // CreateContainer creates a new container in specified PodSandbox
    rpc CreateContainer(CreateContainerRequest) returns (CreateContainerResponse) {}
    // StartContainer starts the container.
    rpc StartContainer(StartContainerRequest) returns (StartContainerResponse) {}
    // StopContainer stops a running container with a grace period (i.e., timeout).
    // This call is idempotent, and must not return an error if the container has
    // already been stopped.
    // TODO: what must the runtime do after the grace period is reached?
    rpc StopContainer(StopContainerRequest) returns (StopContainerResponse) {}
    // RemoveContainer removes the container. If the container is running, the
    // container must be forcibly removed.
    // This call is idempotent, and must not return an error if the container has
    // already been removed.
    rpc RemoveContainer(RemoveContainerRequest) returns (RemoveContainerResponse) {}
    // ListContainers lists all containers by filters.
    rpc ListContainers(ListContainersRequest) returns (ListContainersResponse) {}
    // ContainerStatus returns status of the container.
    rpc ContainerStatus(ContainerStatusRequest) returns (ContainerStatusResponse) {}

    // ExecSync runs a command in a container synchronously.
    rpc ExecSync(ExecSyncRequest) returns (ExecSyncResponse) {}
    // Exec prepares a streaming endpoint to execute a command in the container.
    rpc Exec(ExecRequest) returns (ExecResponse) {}
    // Attach prepares a streaming endpoint to attach to a running container.
    rpc Attach(AttachRequest) returns (AttachResponse) {}
    // PortForward prepares a streaming endpoint to forward ports from a PodSandbox.
    rpc PortForward(PortForwardRequest) returns (PortForwardResponse) {}

    // UpdateRuntimeConfig updates the runtime configuration based on the given request.
    rpc UpdateRuntimeConfig(UpdateRuntimeConfigRequest) returns (UpdateRuntimeConfigResponse) {}

    // Status returns the status of the runtime.
    rpc Status(StatusRequest) returns (StatusResponse) {}
}

// ImageService defines the public APIs for managing images.
service ImageService {
    // ListImages lists existing images.
    rpc ListImages(ListImagesRequest) returns (ListImagesResponse) {}
    // ImageStatus returns the status of the image. If the image is not
    // present, returns nil.
    rpc ImageStatus(ImageStatusRequest) returns (ImageStatusResponse) {}
    // PullImage pulls an image with authentication config.
    rpc PullImage(PullImageRequest) returns (PullImageResponse) {}
    // RemoveImage removes the image.
    // This call is idempotent, and must not return an error if the image has
    // already been removed.
    rpc RemoveImage(RemoveImageRequest) returns (RemoveImageResponse) {}
}

message VersionRequest {
    // Version of the kubelet runtime API.
    optional string version = 1;
}

message VersionResponse {
    // Version of the kubelet runtime API.
    optional string version = 1;
    // Name of the container runtime.
    optional string runtime_name = 2;
    // Version of the container runtime. The string must be
    // semver-compatible.
    optional string runtime_version = 3;
    // API version of the container runtime. The string must be
    // semver-compatible.
    optional string runtime_api_version = 4;
}

// DNSConfig specifies the DNS servers and search domains of a sandbox.
message DNSConfig {
    // List of DNS servers of the cluster.
    repeated string servers = 1;
    // List of DNS search domains of the cluster.
    repeated string searches = 2;
    // List of DNS options. See https://linux.die.net/man/5/resolv.conf
    // for all available options.
    repeated string options = 3;
}

enum Protocol {
    TCP = 0;
    UDP = 1;
}

// PortMapping specifies the port mapping configurations of a sandbox.
message PortMapping {
    // Protocol of the port mapping.
    optional Protocol protocol = 1;
    // Port number within the container.
    optional int32 container_port = 2;
    // Port number on the host.
    optional int32 host_port = 3;
    // Host IP.
    optional string host_ip = 4;
}

// Mount specifies a host volume to mount into a container.
message Mount {
    // Path of the mount within the container.
    optional string container_path = 1;
    // Path of the mount on the host.
    optional string host_path = 2;
    // If set, the mount is read-only.
    optional bool readonly = 3;
    // If set, the mount needs SELinux relabeling.
    optional bool selinux_relabel = 4;
}

// NamespaceOption provides options for Linux namespaces.
message NamespaceOption {
    // If set, use the host's network namespace.
    optional bool host_network = 1;
    // If set, use the host's PID namespace.
    optional bool host_pid = 2;
    // If set, use the host's IPC namespace.
    optional bool host_ipc = 3;
}

// LinuxSandboxSecurityContext holds linux security configuration that will be
// applied to a sandbox. Note that:
// 1) It does not apply to containers in the pods.
// 2) It may not be applicable to a PodSandbox which does not contain any running
//    process.
message LinuxSandboxSecurityContext {
    // Configurations for the sandbox's namespaces.
    // This will be used only if the PodSandbox uses namespace for isolation.
    optional NamespaceOption namespace_options = 1;
    // Optional SELinux context to be applied.
    optional SELinuxOption selinux_options = 2;
    // User to run the entrypoint of the sandbox process. Can be either UID or
    // user name.
    optional string run_as_user = 3;
    // If set, the root filesystem of the sandbox is read-only.
    optional bool readonly_rootfs = 4;
    // List of groups applied to the first process run in the sandbox, in
    // addition to the sandbox's primary GID.
    repeated int64 supplemental_groups = 5;
}

// LinuxPodSandboxConfig holds platform-specific configurations for Linux
// host platforms and Linux-based containers.
message LinuxPodSandboxConfig {
    // Parent cgroup of the PodSandbox.
    // The cgroupfs style syntax will be used, but the container runtime can
    // convert it to systemd semantics if needed.
    optional string cgroup_parent = 1;
    // LinuxSandboxSecurityContext holds sandbox security attributes.
    optional LinuxSandboxSecurityContext security_context = 2;
}

// PodSandboxMetadata holds all necessary information for building the sandbox name.
// The container runtime is encouraged to expose the metadata associated with the
// PodSandbox in its user interface for better user experience. For example,
// the runtime can construct a unique PodSandboxName based on the metadata.
message PodSandboxMetadata {
    // Pod name of the sandbox. Same as the pod name in the PodSpec.
    optional string name = 1;
    // Pod UID of the sandbox. Same as the pod UID in the PodSpec.
    optional string uid = 2;
    // Pod namespace of the sandbox. Same as the pod namespace in the PodSpec.
    optional string namespace = 3;
    // Attempt number of creating the sandbox.
    optional uint32 attempt = 4;
}

// PodSandboxConfig holds all the required and optional fields for creating a
// sandbox.
message PodSandboxConfig {
    // Metadata of the sandbox. This information will uniquely identify the
    // sandbox, and the runtime should leverage this to ensure correct
    // operation. The runtime may also use this information to improve UX, such
    // as by constructing a readable name.
    optional PodSandboxMetadata metadata = 1;
    // Hostname of the sandbox.
    optional string hostname = 2;
    // Path to the directory on the host in which container log files are
    // stored.
    // By default the log of a container going into the LogDirectory will be
    // hooked up to STDOUT and STDERR. However, the LogDirectory may contain
    // binary log files with structured logging data from the individual
    // containers. For example, the files might be newline separated JSON
    // structured logs, systemd-journald journal files, gRPC trace files, etc.
    // E.g.,
    //     PodSandboxConfig.LogDirectory = `/var/log/pods/<podUID>/`
    //     ContainerConfig.LogPath = `containerName_Instance#.log`
    //
    // WARNING: Log management and how kubelet should interface with the
    // container logs are under active discussion in
    // https://issues.k8s.io/24677. There *may* be future change of direction
    // for logging as the discussion carries on.
    optional string log_directory = 3;
    // DNS config for the sandbox.
    optional DNSConfig dns_config = 4;
    // Port mappings for the sandbox.
    repeated PortMapping port_mappings = 5;
    // Key-value pairs that may be used to scope and select individual resources.
    map<string, string> labels = 6;
    // Annotations is an unstructured key value map that may be set by external
    // tools to store and retrieve arbitrary metadata. There are a few features are
    // driven by annotations, Runtimes could support them optionally:
    //
    // 1. AppArmor
    //
    //    key: container.apparmor.security.beta.kubernetes.io/<container_name>
    //    description: apparmor profile for the container.
    //    value:
    //      * runtime/default: equivalent to not specifying a profile.
    //      * localhost/<profile_name>: profile loaded on the node
    //        (localhost) by name. The possible profile names are detailed at
    //        http://wiki.apparmor.net/index.php/AppArmor_Core_Policy_Reference
    //
    // 2. Seccomp
    //
    //      key: security.alpha.kubernetes.io/seccomp/pod
    //      description: the seccomp profile for the containers of an entire pod.
    //      value: see below.
    //
    //      key: security.alpha.kubernetes.io/seccomp/container/<container name>
    //      description: the seccomp profile for the container (overides pod).
    //      values: see below
    //
    //      The value of seccomp is runtime agnostic:
    //      * runtime/default: the default profile for the container runtime
    //      * unconfined: unconfined profile, ie, no seccomp sandboxing
    //      * localhost/<profile-name>: the profile installed to the node's
    //        local seccomp profile root
    //
    map<string, string> annotations = 7;
    // Optional configurations specific to Linux hosts.
    optional LinuxPodSandboxConfig linux = 8;
}

message RunPodSandboxRequest {
    // Configuration for creating a PodSandbox.
    optional PodSandboxConfig config = 1;
}

message RunPodSandboxResponse {
    // ID of the PodSandbox to run.
    optional string pod_sandbox_id = 1;
}

message StopPodSandboxRequest {
    // ID of the PodSandbox to stop.
    optional string pod_sandbox_id = 1;
}

message StopPodSandboxResponse {}

message RemovePodSandboxRequest {
    // ID of the PodSandbox to remove.
    optional string pod_sandbox_id = 1;
}

message RemovePodSandboxResponse {}

message PodSandboxStatusRequest {
    // ID of the PodSandbox for which to retrieve status.
    optional string pod_sandbox_id = 1;
}

// PodSandboxNetworkStatus is the status of the network for a PodSandbox.
message PodSandboxNetworkStatus {
    // IP address of the PodSandbox.
    optional string ip = 1;
}

// Namespace contains paths to the namespaces.
message Namespace {
    // Path to the network namespace.
    optional string network = 1;
    // Namespace options for Linux namespaces.
    optional NamespaceOption options = 2;
}

// LinuxSandboxStatus contains status specific to Linux sandboxes.
message LinuxPodSandboxStatus {
    // Paths to the sandbox's namespaces.
    optional Namespace namespaces = 1;
}

enum PodSandboxState {
    SANDBOX_READY = 0;
    SANDBOX_NOTREADY = 1;
}

// PodSandboxStatus contains the status of the PodSandbox.
message PodSandboxStatus {
    // ID of the sandbox.
    optional string id = 1;
    // Metadata of the sandbox.
    optional PodSandboxMetadata metadata = 2;
    // State of the sandbox.
    optional PodSandboxState state = 3;
    // Creation timestamp of the sandbox in nanoseconds.
    optional int64 created_at = 4;
    // Network contains network status if network is handled by the runtime.
    optional PodSandboxNetworkStatus network = 5;
    // Linux-specific status to a pod sandbox.
    optional LinuxPodSandboxStatus linux = 6;
    // Labels are key value pairs that may be used to scope and select individual resources.
    map<string, string> labels = 7;
    // Annotations is an unstructured key value map that may be set by external
    // tools to store and retrieve arbitrary metadata.
    map<string, string> annotations = 8;
}

message PodSandboxStatusResponse {
    // Status of the PodSandbox.
    optional PodSandboxStatus status = 1;
}

// PodSandboxFilter is used to filter a list of PodSandboxes.
// All those fields are combined with 'AND'
message PodSandboxFilter {
    // ID of the sandbox.
    optional string id = 1;
    // State of the sandbox.
    optional PodSandboxState state = 2;
    // LabelSelector to select matches.
    // Only api.MatchLabels is supported for now and the requirements
    // are ANDed. MatchExpressions is not supported yet.
    map<string, string> label_selector = 3;
}

message ListPodSandboxRequest {
    // PodSandboxFilter to filter a list of PodSandboxes.
    optional PodSandboxFilter filter = 1;
}


// PodSandbox contains minimal information about a sandbox.
message PodSandbox {
    // ID of the PodSandbox.
    optional string id = 1;
    // Metadata of the PodSandbox.
    optional PodSandboxMetadata metadata = 2;
    // State of the PodSandbox.
    optional PodSandboxState state = 3;
    // Creation timestamps of the PodSandbox in nanoseconds.
    optional int64 created_at = 4;
    // Labels of the PodSandbox.
    map<string, string> labels = 5;
    // Annotations is an unstructured key value map that may be set by external
    // tools to store and retrieve arbitrary metadata.
    map<string, string> annotations = 6;
}

message ListPodSandboxResponse {
    // List of PodSandboxes.
    repeated PodSandbox items = 1;
}

// ImageSpec is an internal representation of an image.  Currently, it wraps the
// value of a Container's Image field (e.g. imageName, imageName:tag, or
// imageName:digest), but in the future it will include more detailed
// information about the different image types.
message ImageSpec {
    optional string image = 1;
}

message KeyValue {
    optional string key = 1;
    optional string value = 2;
}

// LinuxContainerResources specifies Linux specific configuration for
// resources.
// TODO: Consider using Resources from opencontainers/runtime-spec/specs-go
// directly.
message LinuxContainerResources {
    // CPU CFS (Completely Fair Scheduler) period.
    optional int64 cpu_period = 1;
    // CPU CFS (Completely Fair Scheduler) quota.
    optional int64 cpu_quota = 2;
    // CPU shares (relative weight vs. other containers).
    optional int64 cpu_shares = 3;
    // Memory limit in bytes.
    optional int64 memory_limit_in_bytes = 4;
    // OOMScoreAdj adjusts the oom-killer score.
    optional int64 oom_score_adj = 5;
}

// SELinuxOption are the labels to be applied to the container.
message SELinuxOption {
    optional string user = 1;
    optional string role = 2;
    optional string type = 3;
    optional string level = 4;
}

// Capability contains the container capabilities to add or drop
message Capability {
    // List of capabilities to add.
    repeated string add_capabilities = 1;
    // List of capabilities to drop.
    repeated string drop_capabilities = 2;
}

// LinuxContainerSecurityContext holds linux security configuration that will be applied to a container.
message LinuxContainerSecurityContext {
    // Capabilities to add or drop.
    optional Capability capabilities = 1;
    // If set, run container in privileged mode.
    optional bool privileged = 2;
    // Configurations for the container's namespaces.
    // Only used if the container uses namespace for isolation.
    optional NamespaceOption namespace_options = 3;
    // SELinux context to be optionally applied.
    optional SELinuxOption selinux_options = 4;
    // The user to run the the container process as. Can be either UID or user
    // name.
    // Defaults to user specified in image metadata if unspecified.
    optional string run_as_user = 5;
    // If set, the root filesystem of the container is read-only.
    optional bool readonly_rootfs = 6;
    // List of groups applied to the first process run in the container, in
    // addition to the container's primary GID.
    repeated int64 supplemental_groups = 7;
}

// LinuxContainerConfig contains platform-specific configuration for
// Linux-based containers.
message LinuxContainerConfig {
    // Resources specification for the container.
    optional LinuxContainerResources resources = 1;
    // LinuxContainerSecurityContext configuration for the container.
    optional LinuxContainerSecurityContext security_context = 2;
}

// ContainerMetadata holds all necessary information for building the container
// name. The container runtime is encouraged to expose the metadata in its user
// interface for better user experience. E.g., runtime can construct a unique
// container name based on the metadata. Note that (name, attempt) is unique
// within a sandbox for the entire lifetime of the sandbox.
message ContainerMetadata {
    // Name of the container. Same as the container name in the PodSpec.
    optional string name = 1;
    // Attempt number of creating the container.
    optional uint32 attempt = 2;
}

// Device specifies a host device to mount into a container.
message Device {
    // Path of the device within the container.
    optional string container_path = 1;
    // Path of the device on the host.
    optional string host_path = 2;
    // Cgroups permissions of the device, candidates are one or more of
    // * r - allows container to read from the specified device.
    // * w - allows container to write to the specified device.
    // * m - allows container to create device files that do not yet exist.
    optional string permissions = 3;
}

// ContainerConfig holds all the required and optional fields for creating a
// container.
message ContainerConfig {
    // Metadata of the container. This information will uniquely identify the
    // container, and the runtime should leverage this to ensure correct
    // operation. The runtime may also use this information to improve UX, such
    // as by constructing a readable name.
    optional ContainerMetadata metadata = 1 ;
    // Image to use.
    optional ImageSpec image = 2;
    // Command to execute (i.e., entrypoint for docker)
    repeated string command = 3;
    // Args for the Command (i.e., command for docker)
    repeated string args = 4;
    // Current working directory of the command.
    optional string working_dir = 5;
    // List of environment variable to set in the container.
    repeated KeyValue envs = 6;
    // Mounts for the container.
    repeated Mount mounts = 7;
    // Devices for the container.
    repeated Device devices = 8;
    // Key-value pairs that may be used to scope and select individual resources.
    // Label keys are of the form:
    //     label-key ::= prefixed-name | name
    //     prefixed-name ::= prefix '/' name
    //     prefix ::= DNS_SUBDOMAIN
    //     name ::= DNS_LABEL
    map<string, string> labels = 9;
    // Annotations is an unstructured key value map that may be set by external
    // tools to store and retrieve arbitrary metadata.
    map<string, string> annotations = 10;
    // Path relative to PodSandboxConfig.LogDirectory for container to store
    // the log (STDOUT and STDERR) on the host.
    // E.g.,
    //     PodSandboxConfig.LogDirectory = `/var/log/pods/<podUID>/`
    //     ContainerConfig.LogPath = `containerName_Instance#.log`
    //
    // WARNING: Log management and how kubelet should interface with the
    // container logs are under active discussion in
    // https://issues.k8s.io/24677. There *may* be future change of direction
    // for logging as the discussion carries on.
    optional string log_path = 11;

    // Variables for interactive containers, these have very specialized
    // use-cases (e.g. debugging).
    // TODO: Determine if we need to continue supporting these fields that are
    // part of Kubernetes's Container Spec.
    optional bool stdin = 12;
    optional bool stdin_once = 13;
    optional bool tty = 14;

    // Configuration specific to Linux containers.
    optional LinuxContainerConfig linux = 15;
}

message CreateContainerRequest {
    // ID of the PodSandbox in which the container should be created.
    optional string pod_sandbox_id = 1;
    // Config of the container.
    optional ContainerConfig config = 2;
    // Config of the PodSandbox. This is the same config that was passed
    // to RunPodSandboxRequest to create the PodSandbox. It is passed again
    // here just for easy reference. The PodSandboxConfig is immutable and
    // remains the same throughout the lifetime of the pod.
    optional PodSandboxConfig sandbox_config = 3;
}

message CreateContainerResponse {
    // ID of the created container.
    optional string container_id = 1;
}

message StartContainerRequest {
    // ID of the container to start.
    optional string container_id = 1;
}

message StartContainerResponse {}

message StopContainerRequest {
    // ID of the container to stop.
    optional string container_id = 1;
    // Timeout, in seconds, to stop the container.
    optional int64 timeout = 2;
}

message StopContainerResponse {}

message RemoveContainerRequest {
    // ID of the container to remove.
    optional string container_id = 1;
}

message RemoveContainerResponse {}

enum ContainerState {
    CONTAINER_CREATED = 0;
    CONTAINER_RUNNING = 1;
    CONTAINER_EXITED  = 2;
    CONTAINER_UNKNOWN = 3;
}

// ContainerFilter is used to filter containers.
// All those fields are combined with 'AND'
message ContainerFilter {
    // ID of the container.
    optional string id = 1;
    // State of the container.
    optional ContainerState state = 2;
    // ID of the PodSandbox.
    optional string pod_sandbox_id = 3;
    // LabelSelector to select matches.
    // Only api.MatchLabels is supported for now and the requirements
    // are ANDed. MatchExpressions is not supported yet.
    map<string, string> label_selector = 4;
}

message ListContainersRequest {
    optional ContainerFilter filter = 1;
}

// Container provides the runtime information for a container, such as ID, hash,
// state of the container.
message Container {
    // ID of the container, used by the container runtime to identify
    // a container.
    optional string id = 1;
    // ID of the sandbox to which this container belongs.
    optional string pod_sandbox_id = 2;
    // Metadata of the container.
    optional ContainerMetadata metadata = 3;
    // Spec of the image.
    optional ImageSpec image = 4;
    // Reference to the image in use. For most runtimes, this should be an
    // image ID.
    optional string image_ref = 5;
    // State of the container.
    optional ContainerState state = 6;
    // Creation time of the container in nanoseconds.
    optional int64 created_at = 7;
    // Key-value pairs that may be used to scope and select individual resources.
    map<string, string> labels = 8;
    // Annotations is an unstructured key value map that may be set by external
    // tools to store and retrieve arbitrary metadata.
    map<string, string> annotations = 9;
}

message ListContainersResponse {
    // List of containers.
    repeated Container containers = 1;
}

message ContainerStatusRequest {
    // ID of the container for which to retrieve status.
    optional string container_id = 1;
}

// ContainerStatus represents the status of a container.
message ContainerStatus {
    // ID of the container.
    optional string id = 1;
    // Metadata of the container.
    optional ContainerMetadata metadata = 2;
    // Status of the container.
    optional ContainerState state = 3;
    // Creation time of the container in nanoseconds.
    optional int64 created_at = 4;
    // Start time of the container in nanoseconds.
    optional int64 started_at = 5;
    // Finish time of the container in nanoseconds.
    optional int64 finished_at = 6;
    // Exit code of the container.
    optional int32 exit_code = 7;
    // Spec of the image.
    optional ImageSpec image = 8;
    // Reference to the image in use. For most runtimes, this should be an
    // image ID
    optional string image_ref = 9;
    // Brief CamelCase string explaining why container is in its current state.
    optional string reason = 10;
    // Human-readable message indicating details about why container is in its
    // current state.
    optional string message = 11;
    // Key-value pairs that may be used to scope and select individual resources.
    map<string,string> labels = 12;
    // Annotations is an unstructured key value map.
    map<string,string> annotations = 13;
    // Mounts for the container.
    repeated Mount mounts = 14;
}

message ContainerStatusResponse {
    // Status of the container.
    optional ContainerStatus status = 1;
}

message ExecSyncRequest {
    // ID of the container.
    optional string container_id = 1;
    // Command to execute.
    repeated string cmd = 2;
    // Timeout in seconds to stop the command. Default: run forever.
    optional int64 timeout = 3;
}

message ExecSyncResponse {
    // Captured command stdout output.
    optional bytes stdout = 1;
    // Captured command stderr output.
    optional bytes stderr = 2;
    // Exit code the command finished with.
    optional int32 exit_code = 3;
}

message ExecRequest {
    // ID of the container in which to execute the command.
    optional string container_id = 1;
    // Command to execute.
    repeated string cmd = 2;
    // Whether use tty.
    optional bool tty = 3;
    // Whether to stream stdin.
    optional bool stdin = 4;
}

message ExecResponse {
    // Fully qualified URL of the exec streaming server.
    optional string url = 1;
}

message AttachRequest {
    // ID of the container to which to attach.
    optional string container_id = 1;
    // Whether to stream stdin.
    optional bool stdin = 2;
}

message AttachResponse {
    // Fully qualified URL of the attach streaming server.
    optional string url = 1;
}

message PortForwardRequest {
    // ID of the container to which to forward the port.
    optional string pod_sandbox_id = 1;
    // Port to forward.
    repeated int32 port = 2;
}

message PortForwardResponse {
    // Fully qualified URL of the port-forward streaming server.
    optional string url = 1;
}

message ImageFilter {
    // Spec of the image.
    optional ImageSpec image = 1;
}

message ListImagesRequest {
    // Filter to list images.
    optional ImageFilter filter = 1;
}

// Basic information about a container image.
message Image {
    // ID of the image.
    optional string id = 1;
    // Other names by which this image is known.
    repeated string repo_tags = 2;
    // Digests by which this image is known.
    repeated string repo_digests = 3;
    // Size of the image in bytes.
    optional uint64 size = 4;
    // User that will run the command(s).
    optional string user = 5;
}

message ListImagesResponse {
    // List of images.
    repeated Image images = 1;
}

message ImageStatusRequest {
    // Spec of the image.
    optional ImageSpec image = 1;
}

message ImageStatusResponse {
    // Status of the image.
    optional Image image = 1;
}

// AuthConfig contains authorization information for connecting to a registry.
message AuthConfig {
    optional string username = 1;
    optional string password = 2;
    optional string auth = 3;
    optional string server_address = 4;
    // IdentityToken is used to authenticate the user and get
    // an access token for the registry.
    optional string identity_token = 5;
    // RegistryToken is a bearer token to be sent to a registry
    optional string registry_token = 6;
}

message PullImageRequest {
    // Spec of the image.
    optional ImageSpec image = 1;
    // Authentication configuration for pulling the image.
    optional AuthConfig auth = 2;
    // Config of the PodSandbox, which is used to pull image in PodSandbox context.
    optional PodSandboxConfig sandbox_config = 3;
}

message PullImageResponse {}

message RemoveImageRequest {
    // Spec of the image to remove.
    optional ImageSpec image = 1;
}

message RemoveImageResponse {}

message NetworkConfig {
    // CIDR to use for pod IP addresses.
    optional string pod_cidr = 1;
}

message RuntimeConfig {
    optional NetworkConfig network_config = 1;
}

message UpdateRuntimeConfigRequest {
    optional RuntimeConfig runtime_config = 1;
}

message UpdateRuntimeConfigResponse {}

// RuntimeCondition contains condition information for the runtime.
// There are 2 kinds of runtime conditions:
// 1. Required condtitions: Conditions are required for kubelet to work
// properly. If any required condition is unmet, the node will be not ready.
// The required conditions include:
//   * RuntimeReady: RuntimeReady means the runtime is up and ready to accept
//   basic containers e.g. container only needs host network.
//   * NetworkReady: NetworkReady means the runtime network is up and ready to
//   accept containers which require container network.
// 2. Optional conditions: Conditions are informative to the user, but kubelet
// will not rely on. Since condition type is an arbitrary string, all conditions
// not required are optional. These conditions will be exposed to users to help
// them understand the status of the system.
message RuntimeCondition {
    // Type of runtime condition.
    optional string type = 1;
    // Status of the condition, one of true/false.
    optional bool status = 2;
    // Brief CamelCase string containing reason for the condition's last transition.
    optional string reason = 3;
    // Human-readable message indicating details about last transition.
    optional string message = 4;
}

// RuntimeStatus is information about the current status of the runtime.
message RuntimeStatus {
    // List of current observed runtime conditions.
    repeated RuntimeCondition conditions = 1;
}

message StatusRequest {}

message StatusResponse {
    // Status of the Runtime.
    optional RuntimeStatus status = 1;
}