From 3c3e014901fd03ea46ff4c5dfa125c6aa148d5ca Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Fri, 22 May 2020 14:18:41 +0100
Subject: [PATCH] Define path prefixes in a package that doesn't create import
 cycles

---
 internal/basecomponent/base.go |  5 +++--
 internal/http/http.go          | 11 +++++++++++
 internal/httpapi.go            | 10 +++-------
 internal/httpapis/paths.go     |  6 ++++++
 4 files changed, 23 insertions(+), 9 deletions(-)
 create mode 100644 internal/httpapis/paths.go

diff --git a/internal/basecomponent/base.go b/internal/basecomponent/base.go
index 45aa454a1..3781cea48 100644
--- a/internal/basecomponent/base.go
+++ b/internal/basecomponent/base.go
@@ -24,6 +24,7 @@ import (
 	"golang.org/x/crypto/ed25519"
 
 	"github.com/matrix-org/dendrite/internal/caching"
+	"github.com/matrix-org/dendrite/internal/httpapis"
 	"github.com/matrix-org/dendrite/internal/keydb"
 	"github.com/matrix-org/dendrite/internal/keydb/cache"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
@@ -103,8 +104,8 @@ func NewBaseDendrite(cfg *config.Dendrite, componentName string, enableHTTPAPIs
 		tracerCloser:   closer,
 		Cfg:            cfg,
 		ImmutableCache: cache,
-		PublicAPIMux:   httpmux.PathPrefix(internal.HTTPPublicPathPrefix).Subrouter().UseEncodedPath(),
-		InternalAPIMux: httpmux.PathPrefix(internal.HTTPInternalPathPrefix).Subrouter().UseEncodedPath(),
+		PublicAPIMux:   httpmux.PathPrefix(httpapis.PublicPathPrefix).Subrouter().UseEncodedPath(),
+		InternalAPIMux: httpmux.PathPrefix(httpapis.InternalPathPrefix).Subrouter().UseEncodedPath(),
 		httpClient:     &http.Client{Timeout: HTTPClientTimeout},
 		KafkaConsumer:  kafkaConsumer,
 		KafkaProducer:  kafkaProducer,
diff --git a/internal/http/http.go b/internal/http/http.go
index 77896a53f..da90b3751 100644
--- a/internal/http/http.go
+++ b/internal/http/http.go
@@ -6,7 +6,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"net/url"
+	"strings"
 
+	"github.com/matrix-org/dendrite/internal/httpapis"
 	opentracing "github.com/opentracing/opentracing-go"
 	"github.com/opentracing/opentracing-go/ext"
 )
@@ -21,6 +24,14 @@ func PostJSON(
 		return err
 	}
 
+	parsedAPIURL, err := url.Parse(apiURL)
+	if err != nil {
+		return err
+	}
+
+	parsedAPIURL.Path = httpapis.InternalPathPrefix + strings.TrimLeft(parsedAPIURL.Path, "/")
+	apiURL = parsedAPIURL.String()
+
 	req, err := http.NewRequest(http.MethodPost, apiURL, bytes.NewReader(jsonBytes))
 	if err != nil {
 		return err
diff --git a/internal/httpapi.go b/internal/httpapi.go
index 526ff8a2d..07bbacdd6 100644
--- a/internal/httpapi.go
+++ b/internal/httpapi.go
@@ -13,6 +13,7 @@ import (
 	"github.com/matrix-org/dendrite/clientapi/auth"
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
 	"github.com/matrix-org/dendrite/internal/config"
+	"github.com/matrix-org/dendrite/internal/httpapis"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 	opentracing "github.com/opentracing/opentracing-go"
@@ -23,11 +24,6 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-const (
-	HTTPPublicPathPrefix   = "/_matrix/"
-	HTTPInternalPathPrefix = "/api/"
-)
-
 // BasicAuth is used for authorization on /metrics handlers
 type BasicAuth struct {
 	Username string `yaml:"username"`
@@ -195,9 +191,9 @@ func SetupHTTPAPI(servMux *http.ServeMux, publicApiMux *mux.Router, internalApiM
 		servMux.Handle("/metrics", WrapHandlerInBasicAuth(promhttp.Handler(), cfg.Metrics.BasicAuth))
 	}
 	if enableHTTPAPIs {
-		servMux.Handle(HTTPInternalPathPrefix, internalApiMux)
+		servMux.Handle(httpapis.InternalPathPrefix, internalApiMux)
 	}
-	servMux.Handle(HTTPPublicPathPrefix, WrapHandlerInCORS(publicApiMux))
+	servMux.Handle(httpapis.PublicPathPrefix, WrapHandlerInCORS(publicApiMux))
 }
 
 // WrapHandlerInBasicAuth adds basic auth to a handler. Only used for /metrics
diff --git a/internal/httpapis/paths.go b/internal/httpapis/paths.go
new file mode 100644
index 000000000..8adec2dff
--- /dev/null
+++ b/internal/httpapis/paths.go
@@ -0,0 +1,6 @@
+package httpapis
+
+const (
+	PublicPathPrefix   = "/_matrix/"
+	InternalPathPrefix = "/api/"
+)