aboutsummaryrefslogtreecommitdiff
path: root/libpod/oci.go
blob: ef46cf5c31d73fe969cee25a68d1c34a7ee373ba (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
package libpod

import (
	"bufio"
	"net"

	"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 may be passed for containers that did not
	// create a terminal and 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 (exit code), error channel (errors from attach), and
	// error (errors that occurred attempting to start the exec session).
	ExecContainer(ctr *Container, sessionID string, options *ExecOptions) (int, chan error, 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

	// 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

	// 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() (map[string]interface{}, 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 *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
}

// 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
}