github.com/hms58/moby@v1.13.1/daemon/exec.go (about) 1 package daemon 2 3 import ( 4 "fmt" 5 "io" 6 "strings" 7 "time" 8 9 "golang.org/x/net/context" 10 11 "github.com/Sirupsen/logrus" 12 "github.com/docker/docker/api/errors" 13 "github.com/docker/docker/api/types" 14 "github.com/docker/docker/api/types/strslice" 15 "github.com/docker/docker/container" 16 "github.com/docker/docker/daemon/exec" 17 "github.com/docker/docker/libcontainerd" 18 "github.com/docker/docker/pkg/pools" 19 "github.com/docker/docker/pkg/signal" 20 "github.com/docker/docker/pkg/term" 21 "github.com/docker/docker/utils" 22 ) 23 24 // Seconds to wait after sending TERM before trying KILL 25 const termProcessTimeout = 10 26 27 func (d *Daemon) registerExecCommand(container *container.Container, config *exec.Config) { 28 // Storing execs in container in order to kill them gracefully whenever the container is stopped or removed. 29 container.ExecCommands.Add(config.ID, config) 30 // Storing execs in daemon for easy access via Engine API. 31 d.execCommands.Add(config.ID, config) 32 } 33 34 // ExecExists looks up the exec instance and returns a bool if it exists or not. 35 // It will also return the error produced by `getConfig` 36 func (d *Daemon) ExecExists(name string) (bool, error) { 37 if _, err := d.getExecConfig(name); err != nil { 38 return false, err 39 } 40 return true, nil 41 } 42 43 // getExecConfig looks up the exec instance by name. If the container associated 44 // with the exec instance is stopped or paused, it will return an error. 45 func (d *Daemon) getExecConfig(name string) (*exec.Config, error) { 46 ec := d.execCommands.Get(name) 47 48 // If the exec is found but its container is not in the daemon's list of 49 // containers then it must have been deleted, in which case instead of 50 // saying the container isn't running, we should return a 404 so that 51 // the user sees the same error now that they will after the 52 // 5 minute clean-up loop is run which erases old/dead execs. 53 54 if ec != nil { 55 if container := d.containers.Get(ec.ContainerID); container != nil { 56 if !container.IsRunning() { 57 return nil, fmt.Errorf("Container %s is not running: %s", container.ID, container.State.String()) 58 } 59 if container.IsPaused() { 60 return nil, errExecPaused(container.ID) 61 } 62 if container.IsRestarting() { 63 return nil, errContainerIsRestarting(container.ID) 64 } 65 return ec, nil 66 } 67 } 68 69 return nil, errExecNotFound(name) 70 } 71 72 func (d *Daemon) unregisterExecCommand(container *container.Container, execConfig *exec.Config) { 73 container.ExecCommands.Delete(execConfig.ID) 74 d.execCommands.Delete(execConfig.ID) 75 } 76 77 func (d *Daemon) getActiveContainer(name string) (*container.Container, error) { 78 container, err := d.GetContainer(name) 79 if err != nil { 80 return nil, err 81 } 82 83 if !container.IsRunning() { 84 return nil, errNotRunning{container.ID} 85 } 86 if container.IsPaused() { 87 return nil, errExecPaused(name) 88 } 89 if container.IsRestarting() { 90 return nil, errContainerIsRestarting(container.ID) 91 } 92 return container, nil 93 } 94 95 // ContainerExecCreate sets up an exec in a running container. 96 func (d *Daemon) ContainerExecCreate(name string, config *types.ExecConfig) (string, error) { 97 container, err := d.getActiveContainer(name) 98 if err != nil { 99 return "", err 100 } 101 102 cmd := strslice.StrSlice(config.Cmd) 103 entrypoint, args := d.getEntrypointAndArgs(strslice.StrSlice{}, cmd) 104 105 keys := []byte{} 106 if config.DetachKeys != "" { 107 keys, err = term.ToBytes(config.DetachKeys) 108 if err != nil { 109 err = fmt.Errorf("Invalid escape keys (%s) provided", config.DetachKeys) 110 return "", err 111 } 112 } 113 114 execConfig := exec.NewConfig() 115 execConfig.OpenStdin = config.AttachStdin 116 execConfig.OpenStdout = config.AttachStdout 117 execConfig.OpenStderr = config.AttachStderr 118 execConfig.ContainerID = container.ID 119 execConfig.DetachKeys = keys 120 execConfig.Entrypoint = entrypoint 121 execConfig.Args = args 122 execConfig.Tty = config.Tty 123 execConfig.Privileged = config.Privileged 124 execConfig.User = config.User 125 126 linkedEnv, err := d.setupLinkedContainers(container) 127 if err != nil { 128 return "", err 129 } 130 execConfig.Env = utils.ReplaceOrAppendEnvValues(container.CreateDaemonEnvironment(config.Tty, linkedEnv), config.Env) 131 if len(execConfig.User) == 0 { 132 execConfig.User = container.Config.User 133 } 134 135 d.registerExecCommand(container, execConfig) 136 137 d.LogContainerEvent(container, "exec_create: "+execConfig.Entrypoint+" "+strings.Join(execConfig.Args, " ")) 138 139 return execConfig.ID, nil 140 } 141 142 // ContainerExecStart starts a previously set up exec instance. The 143 // std streams are set up. 144 // If ctx is cancelled, the process is terminated. 145 func (d *Daemon) ContainerExecStart(ctx context.Context, name string, stdin io.ReadCloser, stdout io.Writer, stderr io.Writer) (err error) { 146 var ( 147 cStdin io.ReadCloser 148 cStdout, cStderr io.Writer 149 ) 150 151 ec, err := d.getExecConfig(name) 152 if err != nil { 153 return errExecNotFound(name) 154 } 155 156 ec.Lock() 157 if ec.ExitCode != nil { 158 ec.Unlock() 159 err := fmt.Errorf("Error: Exec command %s has already run", ec.ID) 160 return errors.NewRequestConflictError(err) 161 } 162 163 if ec.Running { 164 ec.Unlock() 165 return fmt.Errorf("Error: Exec command %s is already running", ec.ID) 166 } 167 ec.Running = true 168 defer func() { 169 if err != nil { 170 ec.Running = false 171 exitCode := 126 172 ec.ExitCode = &exitCode 173 } 174 }() 175 ec.Unlock() 176 177 c := d.containers.Get(ec.ContainerID) 178 logrus.Debugf("starting exec command %s in container %s", ec.ID, c.ID) 179 d.LogContainerEvent(c, "exec_start: "+ec.Entrypoint+" "+strings.Join(ec.Args, " ")) 180 181 if ec.OpenStdin && stdin != nil { 182 r, w := io.Pipe() 183 go func() { 184 defer w.Close() 185 defer logrus.Debug("Closing buffered stdin pipe") 186 pools.Copy(w, stdin) 187 }() 188 cStdin = r 189 } 190 if ec.OpenStdout { 191 cStdout = stdout 192 } 193 if ec.OpenStderr { 194 cStderr = stderr 195 } 196 197 if ec.OpenStdin { 198 ec.StreamConfig.NewInputPipes() 199 } else { 200 ec.StreamConfig.NewNopInputPipe() 201 } 202 203 p := libcontainerd.Process{ 204 Args: append([]string{ec.Entrypoint}, ec.Args...), 205 Env: ec.Env, 206 Terminal: ec.Tty, 207 } 208 209 if err := execSetPlatformOpt(c, ec, &p); err != nil { 210 return err 211 } 212 213 attachErr := container.AttachStreams(ctx, ec.StreamConfig, ec.OpenStdin, true, ec.Tty, cStdin, cStdout, cStderr, ec.DetachKeys) 214 215 systemPid, err := d.containerd.AddProcess(ctx, c.ID, name, p, ec.InitializeStdio) 216 if err != nil { 217 return err 218 } 219 ec.Lock() 220 ec.Pid = systemPid 221 ec.Unlock() 222 223 select { 224 case <-ctx.Done(): 225 logrus.Debugf("Sending TERM signal to process %v in container %v", name, c.ID) 226 d.containerd.SignalProcess(c.ID, name, int(signal.SignalMap["TERM"])) 227 select { 228 case <-time.After(termProcessTimeout * time.Second): 229 logrus.Infof("Container %v, process %v failed to exit within %d seconds of signal TERM - using the force", c.ID, name, termProcessTimeout) 230 d.containerd.SignalProcess(c.ID, name, int(signal.SignalMap["KILL"])) 231 case <-attachErr: 232 // TERM signal worked 233 } 234 return fmt.Errorf("context cancelled") 235 case err := <-attachErr: 236 if err != nil { 237 if _, ok := err.(container.DetachError); !ok { 238 return fmt.Errorf("exec attach failed with error: %v", err) 239 } 240 d.LogContainerEvent(c, "exec_detach") 241 } 242 } 243 return nil 244 } 245 246 // execCommandGC runs a ticker to clean up the daemon references 247 // of exec configs that are no longer part of the container. 248 func (d *Daemon) execCommandGC() { 249 for range time.Tick(5 * time.Minute) { 250 var ( 251 cleaned int 252 liveExecCommands = d.containerExecIds() 253 ) 254 for id, config := range d.execCommands.Commands() { 255 if config.CanRemove { 256 cleaned++ 257 d.execCommands.Delete(id) 258 } else { 259 if _, exists := liveExecCommands[id]; !exists { 260 config.CanRemove = true 261 } 262 } 263 } 264 if cleaned > 0 { 265 logrus.Debugf("clean %d unused exec commands", cleaned) 266 } 267 } 268 } 269 270 // containerExecIds returns a list of all the current exec ids that are in use 271 // and running inside a container. 272 func (d *Daemon) containerExecIds() map[string]struct{} { 273 ids := map[string]struct{}{} 274 for _, c := range d.containers.List() { 275 for _, id := range c.ExecCommands.List() { 276 ids[id] = struct{}{} 277 } 278 } 279 return ids 280 }