package libpod import ( "bufio" "net" "github.com/containers/podman/v2/libpod/define" "k8s.io/client-go/tools/remotecommand" ) // OCIRuntime is an implementation of an OCI runtime. // The OCI runtime implementation is expected to be a fairly thin wrapper around // the actual runtime, and is not expected to include things like state // management logic - e.g., we do not expect it to determine on its own that // calling 'UnpauseContainer()' on a container that is not paused is an error. // The code calling the OCIRuntime will manage this. // TODO: May want to move the Attach() code under this umbrella. It's highly OCI // runtime dependent. // TODO: May want to move the conmon cleanup code here too - it depends on // Conmon being in use. type OCIRuntime interface { // Name returns the name of the runtime. Name() string // Path returns the path to the runtime executable. Path() string // CreateContainer creates the container in the OCI runtime. CreateContainer(ctr *Container, restoreOptions *ContainerCheckpointOptions) error // UpdateContainerStatus updates the status of the given container. UpdateContainerStatus(ctr *Container) error // StartContainer starts the given container. StartContainer(ctr *Container) error // KillContainer sends the given signal to the given container. // If all is set, all processes in the container will be signalled; // otherwise, only init will be signalled. KillContainer(ctr *Container, signal uint, all bool) error // StopContainer stops the given container. // The container's stop signal (or SIGTERM if unspecified) will be sent // first. // After the given timeout, SIGKILL will be sent. // If the given timeout is 0, SIGKILL will be sent immediately, and the // stop signal will be omitted. // If all is set, we will attempt to use the --all flag will `kill` in // the OCI runtime to kill all processes in the container, including // exec sessions. This is only supported if the container has cgroups. StopContainer(ctr *Container, timeout uint, all bool) error // DeleteContainer deletes the given container from the OCI runtime. DeleteContainer(ctr *Container) error // PauseContainer pauses the given container. PauseContainer(ctr *Container) error // UnpauseContainer unpauses the given container. UnpauseContainer(ctr *Container) error // HTTPAttach performs an attach intended to be transported over HTTP. // For terminal attach, the container's output will be directly streamed // to output; otherwise, STDOUT and STDERR will be multiplexed, with // a header prepended as follows: 1-byte STREAM (0, 1, 2 for STDIN, // STDOUT, STDERR), 3 null (0x00) bytes, 4-byte big endian length. // If a cancel channel is provided, it can be used to asynchronously // termninate the attach session. Detach keys, if given, will also cause // the attach session to be terminated if provided via the STDIN // channel. If they are not provided, the default detach keys will be // used instead. Detach keys of "" will disable detaching via keyboard. // The streams parameter will determine which streams to forward to the // client. HTTPAttach(ctr *Container, httpConn net.Conn, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool) error // AttachResize resizes the terminal in use by the given container. AttachResize(ctr *Container, newSize remotecommand.TerminalSize) error // ExecContainer executes a command in a running container. // Returns an int (PID of exec session), error channel (errors from // attach), and error (errors that occurred attempting to start the exec // session). This returns once the exec session is running - not once it // has completed, as one might expect. The attach session will remain // running, in a goroutine that will return via the chan error in the // return signature. ExecContainer(ctr *Container, sessionID string, options *ExecOptions, streams *define.AttachStreams) (int, chan error, error) // ExecContainerHTTP executes a command in a running container and // attaches its standard streams to a provided hijacked HTTP session. // Maintains the same invariants as ExecContainer (returns on session // start, with a goroutine running in the background to handle attach). // The HTTP attach itself maintains the same invariants as HTTPAttach. ExecContainerHTTP(ctr *Container, sessionID string, options *ExecOptions, httpConn net.Conn, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, cancel <-chan bool) (int, chan error, error) // ExecContainerDetached executes a command in a running container, but // does not attach to it. Returns the PID of the exec session and an // error (if starting the exec session failed) ExecContainerDetached(ctr *Container, sessionID string, options *ExecOptions, stdin bool) (int, error) // ExecAttachResize resizes the terminal of a running exec session. Only // allowed with sessions that were created with a TTY. ExecAttachResize(ctr *Container, sessionID string, newSize remotecommand.TerminalSize) error // ExecStopContainer stops a given exec session in a running container. // SIGTERM with be sent initially, then SIGKILL after the given timeout. // If timeout is 0, SIGKILL will be sent immediately, and SIGTERM will // be omitted. ExecStopContainer(ctr *Container, sessionID string, timeout uint) error // ExecUpdateStatus checks the status of a given exec session. // Returns true if the session is still running, or false if it exited. ExecUpdateStatus(ctr *Container, sessionID string) (bool, error) // ExecContainerCleanup cleans up after an exec session exits. // It removes any files left by the exec session that are no longer // needed, including the attach socket. ExecContainerCleanup(ctr *Container, sessionID string) error // CheckpointContainer checkpoints the given container. // Some OCI runtimes may not support this - if SupportsCheckpoint() // returns false, this is not implemented, and will always return an // error. CheckpointContainer(ctr *Container, options ContainerCheckpointOptions) error // CheckConmonRunning verifies that the given container's Conmon // instance is still running. Runtimes without Conmon, or systems where // the PID of conmon is not available, should mock this as True. // True indicates that Conmon for the instance is running, False // indicates it is not. CheckConmonRunning(ctr *Container) (bool, error) // SupportsCheckpoint returns whether this OCI runtime // implementation supports the CheckpointContainer() operation. SupportsCheckpoint() bool // SupportsJSONErrors is whether the runtime can return JSON-formatted // error messages. SupportsJSONErrors() bool // SupportsNoCgroups is whether the runtime supports running containers // without cgroups. SupportsNoCgroups() bool // SupportsKVM os whether the OCI runtime supports running containers // without KVM separation SupportsKVM() bool // AttachSocketPath is the path to the socket to attach to a given // container. // TODO: If we move Attach code in here, this should be made internal. // We don't want to force all runtimes to share the same attach // implementation. AttachSocketPath(ctr *Container) (string, error) // ExecAttachSocketPath is the path to the socket to attach to a given // exec session in the given container. // TODO: Probably should be made internal. ExecAttachSocketPath(ctr *Container, sessionID string) (string, error) // ExitFilePath is the path to a container's exit file. // All runtime implementations must create an exit file when containers // exit, containing the exit code of the container (as a string). // This is the path to that file for a given container. ExitFilePath(ctr *Container) (string, error) // RuntimeInfo returns verbose information about the runtime. RuntimeInfo() (*define.ConmonInfo, *define.OCIRuntimeInfo, error) } // ExecOptions are options passed into ExecContainer. They control the command // that will be executed and how the exec will proceed. type ExecOptions struct { // Cmd is the command to execute. Cmd []string // CapAdd is a set of capabilities to add to the executed command. CapAdd []string // Env is a set of environment variables to add to the container. Env map[string]string // Terminal is whether to create a new TTY for the exec session. Terminal bool // Cwd is the working directory for the executed command. If unset, the // working directory of the container will be used. Cwd string // User is the user the command will be executed as. If unset, the user // the container was run as will be used. User string // Streams are the streams that will be attached to the container. Streams *define.AttachStreams // PreserveFDs is a number of additional file descriptors (in addition // to 0, 1, 2) that will be passed to the executed process. The total FDs // passed will be 3 + PreserveFDs. PreserveFDs uint // DetachKeys is a set of keys that, when pressed in sequence, will // detach from the container. // If not provided, the default keys will be used. // If provided but set to "", detaching from the container will be // disabled. DetachKeys *string // ExitCommand is a command that will be run after the exec session // exits. ExitCommand []string // ExitCommandDelay is a delay (in seconds) between the exec session // exiting, and the exit command being invoked. ExitCommandDelay uint } // HTTPAttachStreams informs the HTTPAttach endpoint which of the container's // standard streams should be streamed to the client. If this is passed, at // least one of the streams must be set to true. type HTTPAttachStreams struct { Stdin bool Stdout bool Stderr bool }