use custom http client instead of the http DefaultClient (#823)

This commit replaces the default client from the http lib with a custom one.
The previously used default client doesn't come with a timeout. This could cause
unwanted locks.
That solution chosen here creates a http client in the base component dendrite
with a constant timeout of 30 seconds. If it should be necessary to overwrite
this, we could include the timeout in the dendrite configuration.
Here it would be a good idea to extend the type "Address" by a timeout and
create an http client for each service.

Closes #820

Signed-off-by: Benedikt Bongartz <benne@klimlive.de>

Co-authored-by: Kegsay <kegan@matrix.org>

roomserver/api/alias.go

@@ -16,6 +16,7 @@ package api
 
 import (
 	"context"
+	"errors"
 	"net/http"
 
 	commonHTTP "github.com/matrix-org/dendrite/common/http"
@@ -139,12 +140,12 @@ const RoomserverGetCreatorIDForAliasPath = "/api/roomserver/GetCreatorIDForAlias
 const RoomserverRemoveRoomAliasPath = "/api/roomserver/removeRoomAlias"
 
 // NewRoomserverAliasAPIHTTP creates a RoomserverAliasAPI implemented by talking to a HTTP POST API.
-// If httpClient is nil then it uses the http.DefaultClient
-func NewRoomserverAliasAPIHTTP(roomserverURL string, httpClient *http.Client) RoomserverAliasAPI {
+// If httpClient is nil an error is returned
+func NewRoomserverAliasAPIHTTP(roomserverURL string, httpClient *http.Client) (RoomserverAliasAPI, error) {
 	if httpClient == nil {
-		httpClient = http.DefaultClient
+		return nil, errors.New("NewRoomserverAliasAPIHTTP: httpClient is <nil>")
 	}
-	return &httpRoomserverAliasAPI{roomserverURL, httpClient}
+	return &httpRoomserverAliasAPI{roomserverURL, httpClient}, nil
 }
 
 type httpRoomserverAliasAPI struct {

roomserver/api/input.go

@@ -17,6 +17,7 @@ package api
 
 import (
 	"context"
+	"errors"
 	"net/http"
 
 	commonHTTP "github.com/matrix-org/dendrite/common/http"
@@ -112,12 +113,12 @@ type RoomserverInputAPI interface {
 const RoomserverInputRoomEventsPath = "/api/roomserver/inputRoomEvents"
 
 // NewRoomserverInputAPIHTTP creates a RoomserverInputAPI implemented by talking to a HTTP POST API.
-// If httpClient is nil then it uses the http.DefaultClient
-func NewRoomserverInputAPIHTTP(roomserverURL string, httpClient *http.Client) RoomserverInputAPI {
+// If httpClient is nil an error is returned
+func NewRoomserverInputAPIHTTP(roomserverURL string, httpClient *http.Client) (RoomserverInputAPI, error) {
 	if httpClient == nil {
-		httpClient = http.DefaultClient
+		return nil, errors.New("NewRoomserverInputAPIHTTP: httpClient is <nil>")
 	}
-	return &httpRoomserverInputAPI{roomserverURL, httpClient}
+	return &httpRoomserverInputAPI{roomserverURL, httpClient}, nil
 }
 
 type httpRoomserverInputAPI struct {

roomserver/api/query.go

@@ -18,6 +18,7 @@ package api
 
 import (
 	"context"
+	"errors"
 	"net/http"
 
 	commonHTTP "github.com/matrix-org/dendrite/common/http"
@@ -406,12 +407,12 @@ const RoomserverQueryRoomVersionCapabilitiesPath = "/api/roomserver/queryRoomVer
 const RoomserverQueryRoomVersionForRoomPath = "/api/roomserver/queryRoomVersionForRoom"
 
 // NewRoomserverQueryAPIHTTP creates a RoomserverQueryAPI implemented by talking to a HTTP POST API.
-// If httpClient is nil then it uses the http.DefaultClient
-func NewRoomserverQueryAPIHTTP(roomserverURL string, httpClient *http.Client) RoomserverQueryAPI {
+// If httpClient is nil an error is returned
+func NewRoomserverQueryAPIHTTP(roomserverURL string, httpClient *http.Client) (RoomserverQueryAPI, error) {
 	if httpClient == nil {
-		httpClient = http.DefaultClient
+		return nil, errors.New("NewRoomserverQueryAPIHTTP: httpClient is <nil>")
 	}
-	return &httpRoomserverQueryAPI{roomserverURL, httpClient}
+	return &httpRoomserverQueryAPI{roomserverURL, httpClient}, nil
 }
 
 type httpRoomserverQueryAPI struct {