Merge pull request #5831 from mheon/exec_http_attach

APIv2 ExecStart (Attached Only)

pkg/api/handlers/compat/containers_attach.go

@@ -13,6 +13,12 @@ import (
 	"k8s.io/client-go/tools/remotecommand"
 )
 
+// 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.
+const AttachHeader = "HTTP/1.1 101 UPGRADED\r\nContent-Type: application/vnd.docker.raw-stream\r\nConnection: Upgrade\r\nUpgrade: tcp\r\n\r\n"
+
 func AttachContainer(w http.ResponseWriter, r *http.Request) {
 	runtime := r.Context().Value("runtime").(*libpod.Runtime)
 	decoder := r.Context().Value("decoder").(*schema.Decoder)
@@ -106,10 +112,7 @@ func AttachContainer(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// This header string sourced from Docker:
-	// https://raw.githubusercontent.com/moby/moby/b95fad8e51bd064be4f4e58a996924f343846c85/api/server/router/container/container_routes.go
-	// Using literally to ensure compatibility with existing clients.
-	fmt.Fprintf(connection, "HTTP/1.1 101 UPGRADED\r\nContent-Type: application/vnd.docker.raw-stream\r\nConnection: Upgrade\r\nUpgrade: tcp\r\n\r\n")
+	fmt.Fprintf(connection, AttachHeader)
 
 	logrus.Debugf("Hijack for attach of container %s successful", ctr.ID())
 

pkg/api/handlers/compat/exec.go

@@ -104,4 +104,76 @@ func ExecInspectHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	utils.WriteResponse(w, http.StatusOK, inspectOut)
+
+	// Only for the Compat API: we want to remove sessions that were
+	// stopped. This is very hacky, but should suffice for now.
+	if !utils.IsLibpodRequest(r) && inspectOut.CanRemove {
+		logrus.Infof("Pruning stale exec session %s from container %s", sessionID, sessionCtr.ID())
+		if err := sessionCtr.ExecRemove(sessionID, false); err != nil && errors.Cause(err) != define.ErrNoSuchExecSession {
+			logrus.Errorf("Error removing stale exec session %s from container %s: %v", sessionID, sessionCtr.ID(), err)
+		}
+	}
+}
+
+// ExecStartHandler runs a given exec session.
+func ExecStartHandler(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+
+	sessionID := mux.Vars(r)["id"]
+
+	// TODO: We should read/support Tty and Detach from here.
+	bodyParams := new(handlers.ExecStartConfig)
+
+	if err := json.NewDecoder(r.Body).Decode(&bodyParams); err != nil {
+		utils.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest,
+			errors.Wrapf(err, "failed to decode parameters for %s", r.URL.String()))
+		return
+	}
+	if bodyParams.Detach {
+		utils.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest,
+			errors.Errorf("Detached exec is not yet supported"))
+		return
+	}
+	// TODO: Verify TTY setting against what inspect session was made with
+
+	sessionCtr, err := runtime.GetExecSessionContainer(sessionID)
+	if err != nil {
+		utils.Error(w, fmt.Sprintf("No such exec session: %s", sessionID), http.StatusNotFound, err)
+		return
+	}
+
+	logrus.Debugf("Starting exec session %s of container %s", sessionID, sessionCtr.ID())
+
+	state, err := sessionCtr.State()
+	if err != nil {
+		utils.InternalServerError(w, err)
+		return
+	}
+	if state != define.ContainerStateRunning {
+		utils.Error(w, http.StatusText(http.StatusConflict), http.StatusConflict, errors.Errorf("cannot exec in a container that is not running; container %s is %s", sessionCtr.ID(), state.String()))
+		return
+	}
+
+	// Hijack the connection
+	hijacker, ok := w.(http.Hijacker)
+	if !ok {
+		utils.InternalServerError(w, errors.Errorf("unable to hijack connection"))
+		return
+	}
+
+	connection, buffer, err := hijacker.Hijack()
+	if err != nil {
+		utils.InternalServerError(w, errors.Wrapf(err, "error hijacking connection"))
+		return
+	}
+
+	fmt.Fprintf(connection, AttachHeader)
+
+	logrus.Debugf("Hijack for attach of container %s exec session %s successful", sessionCtr.ID(), sessionID)
+
+	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)
+	}
+
+	logrus.Debugf("Attach for container %s exec session %s completed successfully", sessionCtr.ID(), sessionID)
 }

pkg/api/handlers/types.go

@@ -170,6 +170,11 @@ type ExecCreateResponse struct {
 	docker.IDResponse
 }
 
+type ExecStartConfig struct {
+	Detach bool `json:"Detach"`
+	Tty    bool `json:"Tty"`
+}
+
 func ImageToImageSummary(l *libpodImage.Image) (*entities.ImageSummary, error) {
 	containers, err := l.Containers()
 	if err != nil {

pkg/api/server/register_exec.go

@@ -97,10 +97,10 @@ func (s *APIServer) registerExecHandlers(r *mux.Router) error {
 	//      properties:
 	//        Detach:
 	//          type: boolean
-	//          description: Detach from the command
+	//          description: Detach from the command. Not presently supported.
 	//        Tty:
 	//          type: boolean
-	//          description: Allocate a pseudo-TTY
+	//          description: Allocate a pseudo-TTY. Presently ignored.
 	// produces:
 	// - application/json
 	// responses:
@@ -109,12 +109,12 @@ func (s *APIServer) registerExecHandlers(r *mux.Router) error {
 	//   404:
 	//     $ref: "#/responses/NoSuchExecInstance"
 	//   409:
-	//	   description: container is stopped or paused
+	//	   description: container is not running
 	//   500:
 	//     $ref: "#/responses/InternalError"
-	r.Handle(VersionedPath("/exec/{id}/start"), s.APIHandler(compat.UnsupportedHandler)).Methods(http.MethodPost)
+	r.Handle(VersionedPath("/exec/{id}/start"), s.APIHandler(compat.ExecStartHandler)).Methods(http.MethodPost)
 	// Added non version path to URI to support docker non versioned paths
-	r.Handle("/exec/{id}/start", s.APIHandler(compat.UnsupportedHandler)).Methods(http.MethodPost)
+	r.Handle("/exec/{id}/start", s.APIHandler(compat.ExecStartHandler)).Methods(http.MethodPost)
 	// swagger:operation POST /exec/{id}/resize compat resizeExec
 	// ---
 	// tags:
@@ -153,7 +153,7 @@ func (s *APIServer) registerExecHandlers(r *mux.Router) error {
 	// tags:
 	//   - exec (compat)
 	// summary: Inspect an exec instance
-	// description: Return low-level information about an exec instance.
+	// description: Return low-level information about an exec instance. Stale (stopped) exec sessions will be auto-removed after inspect runs.
 	// parameters:
 	//  - in: path
 	//    name: id
@@ -264,10 +264,10 @@ func (s *APIServer) registerExecHandlers(r *mux.Router) error {
 	//      properties:
 	//        Detach:
 	//          type: boolean
-	//          description: Detach from the command
+	//          description: Detach from the command. Not presently supported.
 	//        Tty:
 	//          type: boolean
-	//          description: Allocate a pseudo-TTY
+	//          description: Allocate a pseudo-TTY. Presently ignored.
 	// produces:
 	// - application/json
 	// responses:
@@ -276,10 +276,10 @@ func (s *APIServer) registerExecHandlers(r *mux.Router) error {
 	//   404:
 	//     $ref: "#/responses/NoSuchExecInstance"
 	//   409:
-	//	   description: container is stopped or paused
+	//	   description: container is not running.
 	//   500:
 	//     $ref: "#/responses/InternalError"
-	r.Handle(VersionedPath("/libpod/exec/{id}/start"), s.APIHandler(compat.UnsupportedHandler)).Methods(http.MethodPost)
+	r.Handle(VersionedPath("/libpod/exec/{id}/start"), s.APIHandler(compat.ExecStartHandler)).Methods(http.MethodPost)
 	// swagger:operation POST /libpod/exec/{id}/resize libpod libpodResizeExec
 	// ---
 	// tags: