Define path prefixes in a package that doesn't create import cycles

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,

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

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

internal/httpapis/paths.go

@@ -0,0 +1,6 @@
+package httpapis
+
+const (
+	PublicPathPrefix   = "/_matrix/"
+	InternalPathPrefix = "/api/"
+)