Send HTTP Hijack headers after successful attach

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>

1 files changed, 3 insertions, 4 deletions

diff --git a/libpod/oci_missing.go b/libpod/oci_missing.go
index 83a6aaf90..9d12972d4 100644
--- a/libpod/oci_missing.go
+++ b/libpod/oci_missing.go
@@ -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()
 }