Merge pull request #4837 from mheon/rework_attach

Add an API for Attach over HTTP API

2 files changed, 329 insertions, 0 deletions

diff --git a/pkg/api/handlers/containers_attach.go b/pkg/api/handlers/containers_attach.go
new file mode 100644
index 000000000..eb306348b
--- /dev/null
+++ b/pkg/api/handlers/containers_attach.go
@@ -0,0 +1,159 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/libpod/define"
+	"github.com/containers/libpod/pkg/api/handlers/utils"
+	"github.com/gorilla/mux"
+	"github.com/gorilla/schema"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"k8s.io/client-go/tools/remotecommand"
+)
+
+func AttachContainer(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	decoder := r.Context().Value("decoder").(*schema.Decoder)
+
+	query := struct {
+		DetachKeys string `schema:"detachKeys"`
+		Logs       bool   `schema:"logs"`
+		Stream     bool   `schema:"stream"`
+		Stdin      bool   `schema:"stdin"`
+		Stdout     bool   `schema:"stdout"`
+		Stderr     bool   `schema:"stderr"`
+	}{}
+	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
+		utils.Error(w, "Error parsing parameters", http.StatusBadRequest, err)
+		return
+	}
+
+	muxVars := mux.Vars(r)
+
+	// Detach keys: explicitly set to "" is very different from unset
+	// TODO: Our format for parsing these may be different from Docker.
+	var detachKeys *string
+	if _, found := muxVars["detachKeys"]; found {
+		detachKeys = &query.DetachKeys
+	}
+
+	streams := new(libpod.HTTPAttachStreams)
+	streams.Stdout = true
+	streams.Stderr = true
+	streams.Stdin = true
+	useStreams := false
+	if _, found := muxVars["stdin"]; found {
+		streams.Stdin = query.Stdin
+		useStreams = true
+	}
+	if _, found := muxVars["stdout"]; found {
+		streams.Stdout = query.Stdout
+		useStreams = true
+	}
+	if _, found := muxVars["stderr"]; found {
+		streams.Stderr = query.Stderr
+		useStreams = true
+	}
+	if !useStreams {
+		streams = nil
+	}
+	if useStreams && !streams.Stdout && !streams.Stderr && !streams.Stdin {
+		utils.Error(w, "Parameter conflict", http.StatusBadRequest, errors.Errorf("at least one of stdin, stdout, stderr must be true"))
+		return
+	}
+
+	// TODO: Investigate supporting these.
+	// Logs replays container logs over the attach socket.
+	// Stream seems to break things up somehow? Not 100% clear.
+	if query.Logs {
+		utils.Error(w, "Unsupported parameter", http.StatusBadRequest, errors.Errorf("the logs parameter to attach is not presently supported"))
+		return
+	}
+	// We only support stream=true or unset
+	if _, found := muxVars["stream"]; found && query.Stream {
+		utils.Error(w, "Unsupported parameter", http.StatusBadRequest, errors.Errorf("the stream parameter to attach is not presently supported"))
+		return
+	}
+
+	name := getName(r)
+	ctr, err := runtime.LookupContainer(name)
+	if err != nil {
+		utils.ContainerNotFound(w, name, err)
+		return
+	}
+
+	state, err := ctr.State()
+	if err != nil {
+		utils.InternalServerError(w, err)
+		return
+	}
+	if !(state == define.ContainerStateCreated || state == define.ContainerStateRunning) {
+		utils.InternalServerError(w, errors.Wrapf(define.ErrCtrStateInvalid, "can only attach to created or running containers"))
+		return
+	}
+
+	// Hijack the connection
+	hijacker, ok := w.(http.Hijacker)
+	if !ok {
+		utils.InternalServerError(w, errors.Errorf("unable to hijack connection"))
+		return
+	}
+
+	w.WriteHeader(http.StatusSwitchingProtocols)
+
+	connection, buffer, err := hijacker.Hijack()
+	if err != nil {
+		utils.InternalServerError(w, errors.Wrapf(err, "error hijacking connection"))
+		return
+	}
+
+	logrus.Debugf("Hijack for attach of container %s successful", ctr.ID())
+
+	// 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); err != nil {
+		// 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)
+	}
+
+	logrus.Debugf("Attach for container %s completed successfully", ctr.ID())
+}
+
+func ResizeContainer(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	decoder := r.Context().Value("decoder").(*schema.Decoder)
+
+	query := struct {
+		Height uint16 `schema:"h"`
+		Width  uint16 `schema:"w"`
+	}{}
+	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
+		// This is not a 400, despite the fact that is should be, for
+		// compatibility reasons.
+		utils.InternalServerError(w, errors.Wrapf(err, "error parsing query options"))
+		return
+	}
+
+	name := getName(r)
+	ctr, err := runtime.LookupContainer(name)
+	if err != nil {
+		utils.ContainerNotFound(w, name, err)
+		return
+	}
+
+	newSize := remotecommand.TerminalSize{
+		Width:  query.Width,
+		Height: query.Height,
+	}
+	if err := ctr.AttachResize(newSize); err != nil {
+		utils.InternalServerError(w, err)
+		return
+	}
+	// This is not a 204, even though we write nothing, for compatibility
+	// reasons.
+	utils.WriteResponse(w, http.StatusOK, "")
+}
diff --git a/pkg/api/server/register_containers.go b/pkg/api/server/register_containers.go
index b275fa4d1..dbe194cd4 100644
--- a/pkg/api/server/register_containers.go
+++ b/pkg/api/server/register_containers.go
@@ -428,6 +428,91 @@ func (s *APIServer) RegisterContainersHandlers(r *mux.Router) error {
 	//   '500':
 	//      "$ref": "#/responses/InternalError"
 	r.HandleFunc(VersionedPath("/containers/{name:..*}/wait"), APIHandler(s.Context, generic.WaitContainer)).Methods(http.MethodPost)
+	// swagger:operation POST /containers/{nameOrID}/attach compat attach
+	// ---
+	// tags:
+	//   - containers (compat)
+	// summary: Attach to a container
+	// description: Hijacks the connection to forward the container's standard streams to the client.
+	// parameters:
+	//  - in: path
+	//    name: nameOrID
+	//    required: true
+	//    description: the name or ID of the container
+	//  - in: query
+	//    name: detachKeys
+	//    required: false
+	//    type: string
+	//    description: keys to use for detaching from the container
+	//  - in: query
+	//    name: logs
+	//    required: false
+	//    type: bool
+	//    description: Not yet supported
+	//  - in: query
+	//    name: stream
+	//    required: false
+	//    type: bool
+	//    default: true
+	//    description: If passed, must be set to true; stream=false is not yet supported
+	//  - in: query
+	//    name: stdout
+	//    required: false
+	//    type: bool
+	//    description: Attach to container STDOUT
+	//  - in: query
+	//    name: stderr
+	//    required: false
+	//    type: bool
+	//    description: Attach to container STDERR
+	//  - in: query
+	//    name: stdin
+	//    required: false
+	//    type: bool
+	//    description: Attach to container STDIN
+	// produces:
+	// - application/json
+	// responses:
+	//   '101':
+	//     description: No error, connection has been hijacked for transporting streams.
+	//   '400':
+	//       "$ref": "#/responses/BadParamError"
+	//   '404':
+	//       "$ref": "#/responses/NoSuchContainer"
+	//   '500':
+	//       "$ref": "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/containers/{name:..*}/attach"), APIHandler(s.Context, handlers.AttachContainer)).Methods(http.MethodPost)
+	// swagger:operation POST /containers/{nameOrID}/resize compat resize
+	// ---
+	// tags:
+	//  - containers (compat)
+	// summary: Resize a container's TTY
+	// description: Resize the terminal attached to a container (for use with Attach).
+	// parameters:
+	//  - in: path
+	//    name: nameOrID
+	//    required: true
+	//    description: the name or ID of the container
+	//  - in: query
+	//    name: h
+	//    type: int
+	//    required: false
+	//    description: Height to set for the terminal, in characters
+	//  - in: query
+	//    name: w
+	//    type: int
+	//    required: false
+	//    description: Width to set for the terminal, in characters
+	// produces:
+	// - application/json
+	// responses:
+	//   '200':
+	//        description: no error
+	//   '404':
+	//       "$ref": "#/responses/NoSuchContainer"
+	//   '500':
+	//       "$ref": "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/containers/{name:..*}/resize"), APIHandler(s.Context, handlers.ResizeContainer)).Methods(http.MethodPost)
 
 	/*
 		libpod endpoints
@@ -823,5 +908,90 @@ func (s *APIServer) RegisterContainersHandlers(r *mux.Router) error {
 	//   '500':
 	//      "$ref": "#/responses/InternalError"
 	r.HandleFunc(VersionedPath("/libpod/containers/{name:..*}/stop"), APIHandler(s.Context, handlers.StopContainer)).Methods(http.MethodPost)
+	// swagger:operation POST /libpod/containers/{nameOrID}/attach libpod attach
+	// ---
+	// tags:
+	//   - containers
+	// summary: Attach to a container
+	// description: Hijacks the connection to forward the container's standard streams to the client.
+	// parameters:
+	//  - in: path
+	//    name: nameOrID
+	//    required: true
+	//    description: the name or ID of the container
+	//  - in: query
+	//    name: detachKeys
+	//    required: false
+	//    type: string
+	//    description: keys to use for detaching from the container
+	//  - in: query
+	//    name: logs
+	//    required: false
+	//    type: bool
+	//    description: Not yet supported
+	//  - in: query
+	//    name: stream
+	//    required: false
+	//    type: bool
+	//    default: true
+	//    description: If passed, must be set to true; stream=false is not yet supported
+	//  - in: query
+	//    name: stdout
+	//    required: false
+	//    type: bool
+	//    description: Attach to container STDOUT
+	//  - in: query
+	//    name: stderr
+	//    required: false
+	//    type: bool
+	//    description: Attach to container STDERR
+	//  - in: query
+	//    name: stdin
+	//    required: false
+	//    type: bool
+	//    description: Attach to container STDIN
+	// produces:
+	// - application/json
+	// responses:
+	//   '101':
+	//     description: No error, connection has been hijacked for transporting streams.
+	//   '400':
+	//       "$ref": "#/responses/BadParamError"
+	//   '404':
+	//       "$ref": "#/responses/NoSuchContainer"
+	//   '500':
+	//       "$ref": "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/libpod/containers/{name:..*}/attach"), APIHandler(s.Context, handlers.AttachContainer)).Methods(http.MethodPost)
+	// swagger:operation POST /libpod/containers/{nameOrID}/resize libpod resize
+	// ---
+	// tags:
+	//  - containers
+	// summary: Resize a container's TTY
+	// description: Resize the terminal attached to a container (for use with Attach).
+	// parameters:
+	//  - in: path
+	//    name: nameOrID
+	//    required: true
+	//    description: the name or ID of the container
+	//  - in: query
+	//    name: h
+	//    type: int
+	//    required: false
+	//    description: Height to set for the terminal, in characters
+	//  - in: query
+	//    name: w
+	//    type: int
+	//    required: false
+	//    description: Width to set for the terminal, in characters
+	// produces:
+	// - application/json
+	// responses:
+	//   '200':
+	//        description: no error
+	//   '404':
+	//       "$ref": "#/responses/NoSuchContainer"
+	//   '500':
+	//       "$ref": "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/libpod/containers/{name:..*}/resize"), APIHandler(s.Context, handlers.ResizeContainer)).Methods(http.MethodPost)
 	return nil
 }