Roomserver perform join (#1001)

* Add PerformJoin template

* Try roomserver perform join

* Send correct server name to FS API

* Pass through content, try to handle multiple server names

* Fix local server checks

* Don't refer to non-existent error

* Add directory lookups of aliases

* Remove unneeded parameters

* Don't repeat join events into the roomserver

* Unmarshal the content, that would help

* Check if the user is already in the room in the fedeationapi too

* Return incompatible room version error

* Use Membership, don't try more servers than needed

* Review comments, make FS API take list of servernames, dedupe them, break out of loop properly on success

* Tweaks

roomserver/api/api.go

@@ -18,6 +18,12 @@ type RoomserverInternalAPI interface {
 		response *InputRoomEventsResponse,
 	) error
 
+	PerformJoin(
+		ctx context.Context,
+		req *PerformJoinRequest,
+		res *PerformJoinResponse,
+	) error
+
 	// Query the latest events and state for a room from the room server.
 	QueryLatestEventsAndState(
 		ctx context.Context,

roomserver/api/perform.go

@@ -0,0 +1,59 @@
+package api
+
+import (
+	"context"
+
+	commonHTTP "github.com/matrix-org/dendrite/common/http"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/opentracing/opentracing-go"
+)
+
+const (
+	// RoomserverPerformJoinPath is the HTTP path for the PerformJoin API.
+	RoomserverPerformJoinPath = "/api/roomserver/performJoin"
+
+	// RoomserverPerformLeavePath is the HTTP path for the PerformLeave API.
+	RoomserverPerformLeavePath = "/api/roomserver/performLeave"
+)
+
+type PerformJoinRequest struct {
+	RoomIDOrAlias string                         `json:"room_id_or_alias"`
+	UserID        string                         `json:"user_id"`
+	Content       map[string]interface{}         `json:"content"`
+	ServerNames   []gomatrixserverlib.ServerName `json:"server_names"`
+}
+
+type PerformJoinResponse struct {
+}
+
+func (h *httpRoomserverInternalAPI) PerformJoin(
+	ctx context.Context,
+	request *PerformJoinRequest,
+	response *PerformJoinResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "PerformJoin")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverPerformJoinPath
+	return commonHTTP.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}
+
+type PerformLeaveRequest struct {
+	RoomID string `json:"room_id"`
+	UserID string `json:"user_id"`
+}
+
+type PerformLeaveResponse struct {
+}
+
+func (h *httpRoomserverInternalAPI) PerformLeave(
+	ctx context.Context,
+	request *PerformLeaveRequest,
+	response *PerformLeaveResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "PerformLeave")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverPerformLeavePath
+	return commonHTTP.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}