dotcloud/docker

package container // import "github.com/docker/docker/api/server/router/container"

import (
    "context"
    "fmt"
    "io"
    "net/http"
    "strconv"

    "github.com/containerd/log"
    "github.com/docker/docker/api/server/httputils"
    "github.com/docker/docker/api/types"
    "github.com/docker/docker/api/types/backend"
    "github.com/docker/docker/api/types/container"
    "github.com/docker/docker/api/types/versions"
    "github.com/docker/docker/errdefs"
    "github.com/docker/docker/pkg/stdcopy"
)

func (s *containerRouter) getExecByID(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
    eConfig, err := s.backend.ContainerExecInspect(vars["id"])
    if err != nil {
        return err
    }

    return httputils.WriteJSON(w, http.StatusOK, eConfig)
}

type execCommandError struct{}

func (execCommandError) Error() string {
    return "No exec command specified"
}

func (execCommandError) InvalidParameter() {}

func (s *containerRouter) postContainerExecCreate(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
    if err := httputils.ParseForm(r); err != nil {
        return err
    }

    execConfig := &container.ExecOptions{}
    if err := httputils.ReadJSON(r, execConfig); err != nil {
        return err
    }

    if len(execConfig.Cmd) == 0 {
        return execCommandError{}
    }

    version := httputils.VersionFromContext(ctx)
    if versions.LessThan(version, "1.42") {
        // Not supported by API versions before 1.42
        execConfig.ConsoleSize = nil
    }

    // Register an instance of Exec in container.
    id, err := s.backend.ContainerExecCreate(vars["name"], execConfig)
    if err != nil {
        log.G(ctx).Errorf("Error setting up exec command in container %s: %v", vars["name"], err)
        return err
    }

    return httputils.WriteJSON(w, http.StatusCreated, &types.IDResponse{
        ID: id,
    })
}

// TODO(vishh): Refactor the code to avoid having to specify stream config as part of both create and start.
func (s *containerRouter) postContainerExecStart(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
    if err := httputils.ParseForm(r); err != nil {
        return err
    }

    var (
        execName                  = vars["name"]
        stdin, inStream           io.ReadCloser
        stdout, stderr, outStream io.Writer
    )

    options := &container.ExecStartOptions{}
    if err := httputils.ReadJSON(r, options); err != nil {
        return err
    }

    if exists, err := s.backend.ExecExists(execName); !exists {
        return err
    }

    if options.ConsoleSize != nil {
        version := httputils.VersionFromContext(ctx)

        // Not supported before 1.42
        if versions.LessThan(version, "1.42") {
            options.ConsoleSize = nil
        }

        // No console without tty
        if !options.Tty {
            options.ConsoleSize = nil
        }
    }

    if !options.Detach {
        var err error
        // Setting up the streaming http interface.
        inStream, outStream, err = httputils.HijackConnection(w)
        if err != nil {
            return err
        }
        defer httputils.CloseStreams(inStream, outStream)

        if _, ok := r.Header["Upgrade"]; ok {
            contentType := types.MediaTypeRawStream
            if !options.Tty && versions.GreaterThanOrEqualTo(httputils.VersionFromContext(ctx), "1.42") {
                contentType = types.MediaTypeMultiplexedStream
            }
            _, _ = fmt.Fprint(outStream, "HTTP/1.1 101 UPGRADED\r\nContent-Type: "+contentType+"\r\nConnection: Upgrade\r\nUpgrade: tcp\r\n")
        } else {
            _, _ = fmt.Fprint(outStream, "HTTP/1.1 200 OK\r\nContent-Type: application/vnd.docker.raw-stream\r\n")
        }

        // copy headers that were removed as part of hijack
        if err := w.Header().WriteSubset(outStream, nil); err != nil {
            return err
        }
        _, _ = fmt.Fprint(outStream, "\r\n")

        stdin = inStream
        if options.Tty {
            stdout = outStream
        } else {
            stderr = stdcopy.NewStdWriter(outStream, stdcopy.Stderr)
            stdout = stdcopy.NewStdWriter(outStream, stdcopy.Stdout)
        }
    }

    // Now run the user process in container.
    //
    // TODO: Maybe we should we pass ctx here if we're not detaching?
    err := s.backend.ContainerExecStart(context.Background(), execName, backend.ExecStartConfig{
        Stdin:       stdin,
        Stdout:      stdout,
        Stderr:      stderr,
        ConsoleSize: options.ConsoleSize,
    })
    if err != nil {
        if options.Detach {
            return err
        }
        _, _ = fmt.Fprintf(stdout, "%v\r\n", err)
        log.G(ctx).Errorf("Error running exec %s in container: %v", execName, err)
    }
    return nil
}

func (s *containerRouter) postContainerExecResize(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
    if err := httputils.ParseForm(r); err != nil {
        return err
    }
    height, err := strconv.Atoi(r.Form.Get("h"))
    if err != nil {
        return errdefs.InvalidParameter(err)
    }
    width, err := strconv.Atoi(r.Form.Get("w"))
    if err != nil {
        return errdefs.InvalidParameter(err)
    }

    return s.backend.ContainerExecResize(vars["name"], height, width)
}