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Send HTTP Hijack headers after successful attach

Browse Source 
Our previous flow was to perform a hijack before passing a
connection into Libpod, and then Libpod would attach to the
container's attach socket and begin forwarding traffic.

A problem emerges: we write the attach header as soon as the
attach complete. As soon as we write the header, the client
assumes that all is ready, and sends a Start request. This Start
may be processed *before* we successfully finish attaching,
causing us to lose output.

The solution is to handle hijacking inside Libpod. Unfortunately,
this requires a downright extensive refactor of the Attach and
HTTP Exec StartAndAttach code. I think the result is an
improvement in some places (a lot more errors will be handled
with a proper HTTP error code, before the hijack occurs) but
other parts, like the relocation of printing container logs, are
just *bad*. Still, we need this fixed now to get CI back into
good shape...

Fixes #7195

Signed-off-by: Matthew Heon <matthew.heon@pm.me>
This commit is contained in:
Matthew Heon
2020-08-24 11:35:01 -04:00
parent 7ccd821397
commit 2ea9dac5e1
11 changed files with 241 additions and 188 deletions
Download Patch File Download Diff File Expand all files Collapse all files

85
libpod/container_api.go
View File

@ -1,18 +1,14 @@
package libpod
import (
"bufio"
"context"
"io/ioutil"
"net"
"net/http"
"os"
"strings"
"sync"
"time"
"github.com/containers/podman/v2/libpod/define"
"github.com/containers/podman/v2/libpod/events"
"github.com/containers/podman/v2/libpod/logs"
"github.com/opentracing/opentracing-go"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
@ -267,15 +263,10 @@ func (c *Container) Attach(streams *define.AttachStreams, keys string, resize <-
// over the socket; if this is not set, but streamLogs is, only the logs will be
// sent.
// At least one of streamAttach and streamLogs must be set.
func (c *Container) HTTPAttach(httpCon net.Conn, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool, streamAttach, streamLogs bool) (deferredErr error) {
isTerminal := false
if c.config.Spec.Process != nil {
isTerminal = c.config.Spec.Process.Terminal
}
// Ensure our contract of writing errors to and closing the HTTP conn is
// honored.
func (c *Container) HTTPAttach(r *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool, streamAttach, streamLogs bool, hijackDone chan<- bool) error {
// Ensure we don't leak a goroutine if we exit before hijack completes.
defer func() {
hijackWriteErrorAndClose(deferredErr, c.ID(), isTerminal, httpCon, httpBuf)
close(hijackDone)
}()
if !c.batched {
@ -299,74 +290,8 @@ func (c *Container) HTTPAttach(httpCon net.Conn, httpBuf *bufio.ReadWriter, stre
logrus.Infof("Performing HTTP Hijack attach to container %s", c.ID())
logSize := 0
if streamLogs {
// Get all logs for the container
logChan := make(chan *logs.LogLine)
logOpts := new(logs.LogOptions)
logOpts.Tail = -1
logOpts.WaitGroup = new(sync.WaitGroup)
errChan := make(chan error)
go func() {
var err error
// In non-terminal mode we need to prepend with the
// stream header.
logrus.Debugf("Writing logs for container %s to HTTP attach", c.ID())
for logLine := range logChan {
if !isTerminal {
device := logLine.Device
var header []byte
headerLen := uint32(len(logLine.Msg))
logSize += len(logLine.Msg)
switch strings.ToLower(device) {
case "stdin":
header = makeHTTPAttachHeader(0, headerLen)
case "stdout":
header = makeHTTPAttachHeader(1, headerLen)
case "stderr":
header = makeHTTPAttachHeader(2, headerLen)
default:
logrus.Errorf("Unknown device for log line: %s", device)
header = makeHTTPAttachHeader(1, headerLen)
}
_, err = httpBuf.Write(header)
if err != nil {
break
}
}
_, err = httpBuf.Write([]byte(logLine.Msg))
if err != nil {
break
}
_, err = httpBuf.Write([]byte("\n"))
if err != nil {
break
}
err = httpBuf.Flush()
if err != nil {
break
}
}
errChan <- err
}()
go func() {
logOpts.WaitGroup.Wait()
close(logChan)
}()
if err := c.ReadLog(context.Background(), logOpts, logChan); err != nil {
return err
}
logrus.Debugf("Done reading logs for container %s, %d bytes", c.ID(), logSize)
if err := <-errChan; err != nil {
return err
}
}
if !streamAttach {
return nil
}
c.newContainerEvent(events.Attach)
return c.ociRuntime.HTTPAttach(c, httpCon, httpBuf, streams, detachKeys, cancel)
return c.ociRuntime.HTTPAttach(c, r, w, streams, detachKeys, cancel, hijackDone, streamAttach, streamLogs)
}
// AttachResize resizes the container's terminal, which is displayed by Attach

24
libpod/container_exec.go
View File

@ -1,9 +1,8 @@
package libpod
import (
"bufio"
"io/ioutil"
"net"
"net/http"
"os"
"path/filepath"
"strconv"
@ -373,17 +372,12 @@ func (c *Container) ExecStartAndAttach(sessionID string, streams *define.AttachS
}
// ExecHTTPStartAndAttach starts and performs an HTTP attach to an exec session.
func (c *Container) ExecHTTPStartAndAttach(sessionID string, httpCon net.Conn, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool) (deferredErr error) {
func (c *Container) ExecHTTPStartAndAttach(sessionID string, r *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool, hijackDone chan<- bool) error {
// TODO: How do we combine streams with the default streams set in the exec session?
// The flow here is somewhat strange, because we need to determine if
// there's a terminal ASAP (for error handling).
// Until we know, assume it's true (don't add standard stream headers).
// Add a defer to ensure our invariant (HTTP session is closed) is
// maintained.
isTerminal := true
// Ensure that we don't leak a goroutine here
defer func() {
hijackWriteErrorAndClose(deferredErr, c.ID(), isTerminal, httpCon, httpBuf)
close(hijackDone)
}()
if !c.batched {
@ -399,8 +393,6 @@ func (c *Container) ExecHTTPStartAndAttach(sessionID string, httpCon net.Conn, h
if !ok {
return errors.Wrapf(define.ErrNoSuchExecSession, "container %s has no exec session with ID %s", c.ID(), sessionID)
}
// We can now finally get the real value of isTerminal.
isTerminal = session.Config.Terminal
// Verify that we are in a good state to continue
if !c.ensureState(define.ContainerStateRunning) {
@ -432,7 +424,13 @@ func (c *Container) ExecHTTPStartAndAttach(sessionID string, httpCon net.Conn, h
streams.Stderr = session.Config.AttachStderr
}
pid, attachChan, err := c.ociRuntime.ExecContainerHTTP(c, session.ID(), execOpts, httpCon, httpBuf, streams, cancel)
holdConnOpen := make(chan bool)
defer func() {
close(holdConnOpen)
}()
pid, attachChan, err := c.ociRuntime.ExecContainerHTTP(c, session.ID(), execOpts, r, w, streams, cancel, hijackDone, holdConnOpen)
if err != nil {
session.State = define.ExecStateStopped
session.ExitCode = define.TranslateExecErrorToExitCode(define.ExecErrorCodeGeneric, err)

7
libpod/oci.go
View File

@ -1,8 +1,7 @@
package libpod
import (
"bufio"
"net"
"net/http"
"github.com/containers/podman/v2/libpod/define"
"k8s.io/client-go/tools/remotecommand"
@ -63,7 +62,7 @@ type OCIRuntime interface {
// 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
HTTPAttach(ctr *Container, r *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool, hijackDone chan<- bool, streamAttach, streamLogs bool) error
// AttachResize resizes the terminal in use by the given container.
AttachResize(ctr *Container, newSize remotecommand.TerminalSize) error
@ -80,7 +79,7 @@ type OCIRuntime interface {
// 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)
ExecContainerHTTP(ctr *Container, sessionID string, options *ExecOptions, r *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, cancel <-chan bool, hijackDone chan<- bool, holdConnOpen <-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)

39
libpod/oci_conmon_exec_linux.go
View File

@ -1,9 +1,9 @@
package libpod
import (
"bufio"
"fmt"
"net"
"net/http"
"os"
"os/exec"
"path/filepath"
@ -80,7 +80,7 @@ func (r *ConmonOCIRuntime) ExecContainer(c *Container, sessionID string, options
// ExecContainerHTTP executes a new command in an existing container and
// forwards its standard streams over an attach
func (r *ConmonOCIRuntime) ExecContainerHTTP(ctr *Container, sessionID string, options *ExecOptions, httpConn net.Conn, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, cancel <-chan bool) (int, chan error, error) {
func (r *ConmonOCIRuntime) ExecContainerHTTP(ctr *Container, sessionID string, options *ExecOptions, req *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, cancel <-chan bool, hijackDone chan<- bool, holdConnOpen <-chan bool) (int, chan error, error) {
if streams != nil {
if !streams.Stdin && !streams.Stdout && !streams.Stderr {
return -1, nil, errors.Wrapf(define.ErrInvalidArg, "must provide at least one stream to attach to")
@ -129,7 +129,7 @@ func (r *ConmonOCIRuntime) ExecContainerHTTP(ctr *Container, sessionID string, o
attachChan := make(chan error)
go func() {
// attachToExec is responsible for closing pipes
attachChan <- attachExecHTTP(ctr, sessionID, httpBuf, streams, pipes, detachKeys, options.Terminal, cancel)
attachChan <- attachExecHTTP(ctr, sessionID, req, w, streams, pipes, detachKeys, options.Terminal, cancel, hijackDone, holdConnOpen)
close(attachChan)
}()
@ -496,7 +496,7 @@ func (r *ConmonOCIRuntime) startExec(c *Container, sessionID string, options *Ex
}
// Attach to a container over HTTP
func attachExecHTTP(c *Container, sessionID string, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, pipes *execPipes, detachKeys []byte, isTerminal bool, cancel <-chan bool) error {
func attachExecHTTP(c *Container, sessionID string, r *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, pipes *execPipes, detachKeys []byte, isTerminal bool, cancel <-chan bool, hijackDone chan<- bool, holdConnOpen <-chan bool) (deferredErr error) {
if pipes == nil || pipes.startPipe == nil || pipes.attachPipe == nil {
return errors.Wrapf(define.ErrInvalidArg, "must provide a start and attach pipe to finish an exec attach")
}
@ -549,6 +549,37 @@ func attachExecHTTP(c *Container, sessionID string, httpBuf *bufio.ReadWriter, s
attachStdin = streams.Stdin
}
// Perform hijack
hijacker, ok := w.(http.Hijacker)
if !ok {
return errors.Errorf("unable to hijack connection")
}
httpCon, httpBuf, err := hijacker.Hijack()
if err != nil {
return errors.Wrapf(err, "error hijacking connection")
}
hijackDone <- true
// Write a header to let the client know what happened
writeHijackHeader(r, httpBuf)
// Force a flush after the header is written.
if err := httpBuf.Flush(); err != nil {
return errors.Wrapf(err, "error flushing HTTP hijack header")
}
go func() {
// We need to hold the connection open until the complete exec
// function has finished. This channel will be closed in a defer
// in that function, so we can wait for it here.
// Can't be a defer, because this would block the function from
// returning.
<-holdConnOpen
hijackWriteErrorAndClose(deferredErr, c.ID(), isTerminal, httpCon, httpBuf)
}()
// Next, STDIN. Avoid entirely if attachStdin unset.
if attachStdin {
go func() {

135
libpod/oci_conmon_linux.go
View File

@ -5,16 +5,19 @@ package libpod
import (
"bufio"
"bytes"
"context"
"fmt"
"io"
"io/ioutil"
"net"
"net/http"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"strings"
"sync"
"syscall"
"text/template"
"time"
@ -22,6 +25,7 @@ import (
"github.com/containers/common/pkg/config"
conmonConfig "github.com/containers/conmon/runner/config"
"github.com/containers/podman/v2/libpod/define"
"github.com/containers/podman/v2/libpod/logs"
"github.com/containers/podman/v2/pkg/cgroups"
"github.com/containers/podman/v2/pkg/errorhandling"
"github.com/containers/podman/v2/pkg/lookup"
@ -503,7 +507,9 @@ func (r *ConmonOCIRuntime) UnpauseContainer(ctr *Container) error {
// this function returns.
// If this is a container with a terminal, we will stream raw. If it is not, we
// will stream with an 8-byte header to multiplex STDOUT and STDERR.
func (r *ConmonOCIRuntime) HTTPAttach(ctr *Container, httpConn net.Conn, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool) (deferredErr error) {
// Returns any errors that occurred, and whether the connection was successfully
// hijacked before that error occurred.
func (r *ConmonOCIRuntime) HTTPAttach(ctr *Container, req *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool, hijackDone chan<- bool, streamAttach, streamLogs bool) (deferredErr error) {
isTerminal := false
if ctr.config.Spec.Process != nil {
isTerminal = ctr.config.Spec.Process.Terminal
@ -521,17 +527,21 @@ func (r *ConmonOCIRuntime) HTTPAttach(ctr *Container, httpConn net.Conn, httpBuf
}
socketPath := buildSocketPath(attachSock)
conn, err := net.DialUnix("unixpacket", nil, &net.UnixAddr{Name: socketPath, Net: "unixpacket"})
if err != nil {
return errors.Wrapf(err, "failed to connect to container's attach socket: %v", socketPath)
}
defer func() {
if err := conn.Close(); err != nil {
logrus.Errorf("unable to close container %s attach socket: %q", ctr.ID(), err)
var conn *net.UnixConn
if streamAttach {
newConn, err := net.DialUnix("unixpacket", nil, &net.UnixAddr{Name: socketPath, Net: "unixpacket"})
if err != nil {
return errors.Wrapf(err, "failed to connect to container's attach socket: %v", socketPath)
}
}()
conn = newConn
defer func() {
if err := conn.Close(); err != nil {
logrus.Errorf("unable to close container %s attach socket: %q", ctr.ID(), err)
}
}()
logrus.Debugf("Successfully connected to container %s attach socket %s", ctr.ID(), socketPath)
logrus.Debugf("Successfully connected to container %s attach socket %s", ctr.ID(), socketPath)
}
detachString := ctr.runtime.config.Engine.DetachKeys
if detachKeys != nil {
@ -554,6 +564,111 @@ func (r *ConmonOCIRuntime) HTTPAttach(ctr *Container, httpConn net.Conn, httpBuf
attachStdin = streams.Stdin
}
logrus.Debugf("Going to hijack container %s attach connection", ctr.ID())
// Alright, let's hijack.
hijacker, ok := w.(http.Hijacker)
if !ok {
return errors.Errorf("unable to hijack connection")
}
httpCon, httpBuf, err := hijacker.Hijack()
if err != nil {
return errors.Wrapf(err, "error hijacking connection")
}
hijackDone <- true
writeHijackHeader(req, httpBuf)
// Force a flush after the header is written.
if err := httpBuf.Flush(); err != nil {
return errors.Wrapf(err, "error flushing HTTP hijack header")
}
defer func() {
hijackWriteErrorAndClose(deferredErr, ctr.ID(), isTerminal, httpCon, httpBuf)
}()
logrus.Debugf("Hijack for container %s attach session done, ready to stream", ctr.ID())
// TODO: This is gross. Really, really gross.
// I want to say we should read all the logs into an array before
// calling this, in container_api.go, but that could take a lot of
// memory...
// On the whole, we need to figure out a better way of doing this,
// though.
logSize := 0
if streamLogs {
logrus.Debugf("Will stream logs for container %s attach session", ctr.ID())
// Get all logs for the container
logChan := make(chan *logs.LogLine)
logOpts := new(logs.LogOptions)
logOpts.Tail = -1
logOpts.WaitGroup = new(sync.WaitGroup)
errChan := make(chan error)
go func() {
var err error
// In non-terminal mode we need to prepend with the
// stream header.
logrus.Debugf("Writing logs for container %s to HTTP attach", ctr.ID())
for logLine := range logChan {
if !isTerminal {
device := logLine.Device
var header []byte
headerLen := uint32(len(logLine.Msg))
logSize += len(logLine.Msg)
switch strings.ToLower(device) {
case "stdin":
header = makeHTTPAttachHeader(0, headerLen)
case "stdout":
header = makeHTTPAttachHeader(1, headerLen)
case "stderr":
header = makeHTTPAttachHeader(2, headerLen)
default:
logrus.Errorf("Unknown device for log line: %s", device)
header = makeHTTPAttachHeader(1, headerLen)
}
_, err = httpBuf.Write(header)
if err != nil {
break
}
}
_, err = httpBuf.Write([]byte(logLine.Msg))
if err != nil {
break
}
_, err = httpBuf.Write([]byte("\n"))
if err != nil {
break
}
err = httpBuf.Flush()
if err != nil {
break
}
}
errChan <- err
}()
go func() {
logOpts.WaitGroup.Wait()
close(logChan)
}()
if err := ctr.ReadLog(context.Background(), logOpts, logChan); err != nil {
return err
}
logrus.Debugf("Done reading logs for container %s, %d bytes", ctr.ID(), logSize)
if err := <-errChan; err != nil {
return err
}
}
if !streamAttach {
logrus.Debugf("Done streaming logs for container %s attach, exiting as attach streaming not requested", ctr.ID())
return nil
}
logrus.Debugf("Forwarding attach output for container %s", ctr.ID())
// Handle STDOUT/STDERR
go func() {
var err error

7
libpod/oci_missing.go
View File

@ -1,9 +1,8 @@
package libpod
import (
"bufio"
"fmt"
"net"
"net/http"
"path/filepath"
"sync"
@ -111,7 +110,7 @@ func (r *MissingRuntime) UnpauseContainer(ctr *Container) error {
}
// HTTPAttach is not available as the runtime is missing
func (r *MissingRuntime) HTTPAttach(ctr *Container, httpConn net.Conn, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool) error {
func (r *MissingRuntime) HTTPAttach(ctr *Container, req *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool, hijackDone chan<- bool, streamAttach, streamLogs bool) error {
return r.printError()
}
@ -126,7 +125,7 @@ func (r *MissingRuntime) ExecContainer(ctr *Container, sessionID string, options
}
// ExecContainerHTTP is not available as the runtime is missing
func (r *MissingRuntime) ExecContainerHTTP(ctr *Container, sessionID string, options *ExecOptions, httpConn net.Conn, httpBuf *bufio.ReadWriter, streams *HTTPAttachStreams, cancel <-chan bool) (int, chan error, error) {
func (r *MissingRuntime) ExecContainerHTTP(ctr *Container, sessionID string, options *ExecOptions, req *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, cancel <-chan bool, hijackDone chan<- bool, holdConnOpen <-chan bool) (int, chan error, error) {
return -1, nil, r.printError()
}

22
libpod/util.go
View File

@ -5,6 +5,7 @@ import (
"encoding/binary"
"fmt"
"io"
"net/http"
"os"
"os/exec"
"path/filepath"
@ -257,6 +258,27 @@ func makeHTTPAttachHeader(stream byte, length uint32) []byte {
return header
}
// writeHijackHeader writes a header appropriate for the type of HTTP Hijack
// that occurred in a hijacked HTTP connection used for attach.
func writeHijackHeader(r *http.Request, conn io.Writer) {
// AttachHeader is the literal header sent for upgraded/hijacked connections for
// attach, sourced from Docker at:
// https://raw.githubusercontent.com/moby/moby/b95fad8e51bd064be4f4e58a996924f343846c85/api/server/router/container/container_routes.go
// Using literally to ensure compatibility with existing clients.
c := r.Header.Get("Connection")
proto := r.Header.Get("Upgrade")
if len(proto) == 0 || !strings.EqualFold(c, "Upgrade") {
// OK - can't upgrade if not requested or protocol is not specified
fmt.Fprintf(conn,
"HTTP/1.1 200 OK\r\nContent-Type: application/vnd.docker.raw-stream\r\n\r\n")
} else {
// Upraded
fmt.Fprintf(conn,
"HTTP/1.1 101 UPGRADED\r\nContent-Type: application/vnd.docker.raw-stream\r\nConnection: Upgrade\r\nUpgrade: %s\r\n\r\n",
proto)
}
}
// Convert OCICNI port bindings into Inspect-formatted port bindings.
func makeInspectPortBindings(bindings []ocicni.PortMapping) map[string][]define.InspectHostPort {
portBindings := make(map[string][]define.InspectHostPort)

82
pkg/api/handlers/compat/containers_attach.go
View File

@ -1,12 +1,7 @@
package compat
import (
"bufio"
"fmt"
"io"
"net"
"net/http"
"strings"
"github.com/containers/podman/v2/libpod"
"github.com/containers/podman/v2/libpod/define"
@ -97,75 +92,30 @@ func AttachContainer(w http.ResponseWriter, r *http.Request) {
return
}
connection, buffer, err := AttachConnection(w, r)
if err != nil {
utils.InternalServerError(w, err)
return
}
logrus.Debugf("Hijack for attach of container %s successful", ctr.ID())
idleTracker := r.Context().Value("idletracker").(*idletracker.IdleTracker)
hijackChan := make(chan bool, 1)
// Perform HTTP attach.
// HTTPAttach will handle everything about the connection from here on
// (including closing it and writing errors to it).
if err := ctr.HTTPAttach(connection, buffer, streams, detachKeys, nil, query.Stream, query.Logs); err != nil {
if err := ctr.HTTPAttach(r, w, streams, detachKeys, nil, query.Stream, query.Logs, hijackChan); err != nil {
hijackComplete := <-hijackChan
// We can't really do anything about errors anymore. HTTPAttach
// should be writing them to the connection.
logrus.Errorf("Error attaching to container %s: %v", ctr.ID(), err)
if hijackComplete {
// We do need to tell the idle tracker that the
// connection has been closed, though. We can guarantee
// that is true after HTTPAttach exits.
idleTracker.TrackHijackedClosed()
} else {
// A hijack was not successfully completed. We need to
// report the error normally.
utils.InternalServerError(w, err)
}
}
logrus.Debugf("Attach for container %s completed successfully", ctr.ID())
}
type HijackedConnection struct {
net.Conn // Connection
idleTracker *idletracker.IdleTracker // Connection tracker
}
func (c HijackedConnection) Close() error {
logrus.Debugf("Hijacked connection closed")
c.idleTracker.TrackHijackedClosed()
return c.Conn.Close()
}
func AttachConnection(w http.ResponseWriter, r *http.Request) (net.Conn, *bufio.ReadWriter, error) {
idleTracker := r.Context().Value("idletracker").(*idletracker.IdleTracker)
// Hijack the connection
hijacker, ok := w.(http.Hijacker)
if !ok {
return nil, nil, errors.Errorf("unable to hijack connection")
}
connection, buffer, err := hijacker.Hijack()
if err != nil {
return nil, nil, errors.Wrapf(err, "error hijacking connection")
}
trackedConnection := HijackedConnection{
Conn: connection,
idleTracker: idleTracker,
}
WriteAttachHeaders(r, trackedConnection)
return trackedConnection, buffer, nil
}
func WriteAttachHeaders(r *http.Request, connection io.Writer) {
// AttachHeader is the literal header sent for upgraded/hijacked connections for
// attach, sourced from Docker at:
// https://raw.githubusercontent.com/moby/moby/b95fad8e51bd064be4f4e58a996924f343846c85/api/server/router/container/container_routes.go
// Using literally to ensure compatibility with existing clients.
c := r.Header.Get("Connection")
proto := r.Header.Get("Upgrade")
if len(proto) == 0 || !strings.EqualFold(c, "Upgrade") {
// OK - can't upgrade if not requested or protocol is not specified
fmt.Fprintf(connection,
"HTTP/1.1 200 OK\r\nContent-Type: application/vnd.docker.raw-stream\r\n\r\n")
} else {
// Upraded
fmt.Fprintf(connection,
"HTTP/1.1 101 UPGRADED\r\nContent-Type: application/vnd.docker.raw-stream\r\nConnection: Upgrade\r\nUpgrade: %s\r\n\r\n",
proto)
}
}

24
pkg/api/handlers/compat/exec.go
View File

@ -10,6 +10,7 @@ import (
"github.com/containers/podman/v2/libpod/define"
"github.com/containers/podman/v2/pkg/api/handlers"
"github.com/containers/podman/v2/pkg/api/handlers/utils"
"github.com/containers/podman/v2/pkg/api/server/idletracker"
"github.com/containers/podman/v2/pkg/specgen/generate"
"github.com/gorilla/mux"
"github.com/pkg/errors"
@ -173,15 +174,24 @@ func ExecStartHandler(w http.ResponseWriter, r *http.Request) {
return
}
connection, buffer, err := AttachConnection(w, r)
if err != nil {
utils.InternalServerError(w, err)
return
}
logrus.Debugf("Hijack for attach of container %s exec session %s successful", sessionCtr.ID(), sessionID)
idleTracker := r.Context().Value("idletracker").(*idletracker.IdleTracker)
hijackChan := make(chan bool, 1)
if err := sessionCtr.ExecHTTPStartAndAttach(sessionID, r, w, nil, nil, nil, hijackChan); err != nil {
hijackComplete := <-hijackChan
if err := sessionCtr.ExecHTTPStartAndAttach(sessionID, connection, buffer, nil, nil, nil); err != nil {
logrus.Errorf("Error attaching to container %s exec session %s: %v", sessionCtr.ID(), sessionID, err)
if hijackComplete {
// We do need to tell the idle tracker that the
// connection has been closed, though. We can guarantee
// that is true after HTTPAttach exits.
idleTracker.TrackHijackedClosed()
} else {
// A hijack was not successfully completed. We need to
// report the error normally.
utils.InternalServerError(w, err)
}
}
logrus.Debugf("Attach for container %s exec session %s completed successfully", sessionCtr.ID(), sessionID)

2
pkg/bindings/containers/attach.go
View File

@ -46,6 +46,8 @@ func Attach(ctx context.Context, nameOrID string, detachKeys *string, logs, stre
stderr = (io.Writer)(nil)
}
logrus.Infof("Going to attach to container %q", nameOrID)
conn, err := bindings.GetClient(ctx)
if err != nil {
return err

2
pkg/bindings/containers/containers.go
View File

@ -13,6 +13,7 @@ import (
"github.com/containers/podman/v2/pkg/bindings"
"github.com/containers/podman/v2/pkg/domain/entities"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
var (
@ -180,6 +181,7 @@ func Restart(ctx context.Context, nameOrID string, timeout *int) error {
// or a partial/full ID. The optional parameter for detach keys are to override the default
// detach key sequence.
func Start(ctx context.Context, nameOrID string, detachKeys *string) error {
logrus.Infof("Going to start container %q", nameOrID)
conn, err := bindings.GetClient(ctx)
if err != nil {
return err