Remove polylith/API mode (#2967)

This removes most of the code used for polylith/API mode.

This removes the `/api` internal endpoints entirely. 

Binary size change roughly 5%: 
```
51437560 Feb 13 10:15 dendrite-monolith-server # old
48759008 Feb 13 10:15 dendrite-monolith-server # new
```

2 files changed, 0 insertions, 228 deletions

diff --git a/cmd/dendrite-monolith-server/main.go b/cmd/dendrite-monolith-server/main.go
deleted file mode 100644
index 6836b642..00000000
--- a/cmd/dendrite-monolith-server/main.go
+++ /dev/null
@@ -1,178 +0,0 @@
-// Copyright 2017 Vector Creations Ltd
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package main
-
-import (
-	"flag"
-	"os"
-
-	"github.com/sirupsen/logrus"
-
-	"github.com/matrix-org/dendrite/appservice"
-	"github.com/matrix-org/dendrite/federationapi"
-	"github.com/matrix-org/dendrite/keyserver"
-	"github.com/matrix-org/dendrite/roomserver"
-	"github.com/matrix-org/dendrite/roomserver/api"
-	"github.com/matrix-org/dendrite/setup"
-	basepkg "github.com/matrix-org/dendrite/setup/base"
-	"github.com/matrix-org/dendrite/setup/config"
-	"github.com/matrix-org/dendrite/setup/mscs"
-	"github.com/matrix-org/dendrite/userapi"
-	uapi "github.com/matrix-org/dendrite/userapi/api"
-)
-
-var (
-	httpBindAddr   = flag.String("http-bind-address", ":8008", "The HTTP listening port for the server")
-	httpsBindAddr  = flag.String("https-bind-address", ":8448", "The HTTPS listening port for the server")
-	apiBindAddr    = flag.String("api-bind-address", "localhost:18008", "The HTTP listening port for the internal HTTP APIs (if -api is enabled)")
-	certFile       = flag.String("tls-cert", "", "The PEM formatted X509 certificate to use for TLS")
-	keyFile        = flag.String("tls-key", "", "The PEM private key to use for TLS")
-	enableHTTPAPIs = flag.Bool("api", false, "Use HTTP APIs instead of short-circuiting (warning: exposes API endpoints!)")
-	traceInternal  = os.Getenv("DENDRITE_TRACE_INTERNAL") == "1"
-)
-
-func main() {
-	cfg := setup.ParseFlags(true)
-	httpAddr := config.HTTPAddress("http://" + *httpBindAddr)
-	httpsAddr := config.HTTPAddress("https://" + *httpsBindAddr)
-	httpAPIAddr := httpAddr
-	options := []basepkg.BaseDendriteOptions{}
-	if *enableHTTPAPIs {
-		logrus.Warnf("DANGER! The -api option is enabled, exposing internal APIs on %q!", *apiBindAddr)
-		httpAPIAddr = config.HTTPAddress("http://" + *apiBindAddr)
-		// If the HTTP APIs are enabled then we need to update the Listen
-		// statements in the configuration so that we know where to find
-		// the API endpoints. They'll listen on the same port as the monolith
-		// itself.
-		cfg.AppServiceAPI.InternalAPI.Connect = httpAPIAddr
-		cfg.ClientAPI.InternalAPI.Connect = httpAPIAddr
-		cfg.FederationAPI.InternalAPI.Connect = httpAPIAddr
-		cfg.KeyServer.InternalAPI.Connect = httpAPIAddr
-		cfg.MediaAPI.InternalAPI.Connect = httpAPIAddr
-		cfg.RoomServer.InternalAPI.Connect = httpAPIAddr
-		cfg.SyncAPI.InternalAPI.Connect = httpAPIAddr
-		cfg.UserAPI.InternalAPI.Connect = httpAPIAddr
-		options = append(options, basepkg.UseHTTPAPIs)
-	}
-
-	base := basepkg.NewBaseDendrite(cfg, "Monolith", options...)
-	defer base.Close() // nolint: errcheck
-
-	federation := base.CreateFederationClient()
-
-	rsImpl := roomserver.NewInternalAPI(base)
-	// call functions directly on the impl unless running in HTTP mode
-	rsAPI := rsImpl
-	if base.UseHTTPAPIs {
-		roomserver.AddInternalRoutes(base.InternalAPIMux, rsImpl, base.EnableMetrics)
-		rsAPI = base.RoomserverHTTPClient()
-	}
-	if traceInternal {
-		rsAPI = &api.RoomserverInternalAPITrace{
-			Impl: rsAPI,
-		}
-	}
-
-	fsAPI := federationapi.NewInternalAPI(
-		base, federation, rsAPI, base.Caches, nil, false,
-	)
-	fsImplAPI := fsAPI
-	if base.UseHTTPAPIs {
-		federationapi.AddInternalRoutes(base.InternalAPIMux, fsAPI, base.EnableMetrics)
-		fsAPI = base.FederationAPIHTTPClient()
-	}
-	keyRing := fsAPI.KeyRing()
-
-	keyImpl := keyserver.NewInternalAPI(base, &base.Cfg.KeyServer, fsAPI, rsAPI)
-	keyAPI := keyImpl
-	if base.UseHTTPAPIs {
-		keyserver.AddInternalRoutes(base.InternalAPIMux, keyAPI, base.EnableMetrics)
-		keyAPI = base.KeyServerHTTPClient()
-	}
-
-	pgClient := base.PushGatewayHTTPClient()
-	userImpl := userapi.NewInternalAPI(base, &cfg.UserAPI, cfg.Derived.ApplicationServices, keyAPI, rsAPI, pgClient)
-	userAPI := userImpl
-	if base.UseHTTPAPIs {
-		userapi.AddInternalRoutes(base.InternalAPIMux, userAPI, base.EnableMetrics)
-		userAPI = base.UserAPIClient()
-	}
-	if traceInternal {
-		userAPI = &uapi.UserInternalAPITrace{
-			Impl: userAPI,
-		}
-	}
-
-	// TODO: This should use userAPI, not userImpl, but the appservice setup races with
-	// the listeners and panics at startup if it tries to create appservice accounts
-	// before the listeners are up.
-	asAPI := appservice.NewInternalAPI(base, userImpl, rsAPI)
-	if base.UseHTTPAPIs {
-		appservice.AddInternalRoutes(base.InternalAPIMux, asAPI, base.EnableMetrics)
-		asAPI = base.AppserviceHTTPClient()
-	}
-
-	// The underlying roomserver implementation needs to be able to call the fedsender.
-	// This is different to rsAPI which can be the http client which doesn't need this
-	// dependency. Other components also need updating after their dependencies are up.
-	rsImpl.SetFederationAPI(fsAPI, keyRing)
-	rsImpl.SetAppserviceAPI(asAPI)
-	rsImpl.SetUserAPI(userAPI)
-	keyImpl.SetUserAPI(userAPI)
-
-	monolith := setup.Monolith{
-		Config:    base.Cfg,
-		Client:    base.CreateClient(),
-		FedClient: federation,
-		KeyRing:   keyRing,
-
-		AppserviceAPI: asAPI,
-		// always use the concrete impl here even in -http mode because adding public routes
-		// must be done on the concrete impl not an HTTP client else fedapi will call itself
-		FederationAPI: fsImplAPI,
-		RoomserverAPI: rsAPI,
-		UserAPI:       userAPI,
-		KeyAPI:        keyAPI,
-	}
-	monolith.AddAllPublicRoutes(base)
-
-	if len(base.Cfg.MSCs.MSCs) > 0 {
-		if err := mscs.Enable(base, &monolith); err != nil {
-			logrus.WithError(err).Fatalf("Failed to enable MSCs")
-		}
-	}
-
-	// Expose the matrix APIs directly rather than putting them under a /api path.
-	go func() {
-		base.SetupAndServeHTTP(
-			httpAPIAddr, // internal API
-			httpAddr,    // external API
-			nil, nil,    // TLS settings
-		)
-	}()
-	// Handle HTTPS if certificate and key are provided
-	if *certFile != "" && *keyFile != "" {
-		go func() {
-			base.SetupAndServeHTTP(
-				basepkg.NoListener, // internal API
-				httpsAddr,          // external API
-				certFile, keyFile,  // TLS settings
-			)
-		}()
-	}
-
-	// We want to block forever to let the HTTP and HTTPS handler serve the APIs
-	base.WaitForShutdown()
-}
diff --git a/cmd/dendrite-monolith-server/main_test.go b/cmd/dendrite-monolith-server/main_test.go
deleted file mode 100644
index efa1a926..00000000
--- a/cmd/dendrite-monolith-server/main_test.go
+++ /dev/null
@@ -1,50 +0,0 @@
-package main
-
-import (
-	"os"
-	"os/signal"
-	"strings"
-	"syscall"
-	"testing"
-)
-
-// This is an instrumented main, used when running integration tests (sytest) with code coverage.
-// Compile: go test -c -race -cover -covermode=atomic -o monolith.debug -coverpkg "github.com/matrix-org/..." ./cmd/dendrite-monolith-server
-// Run the monolith: ./monolith.debug -test.coverprofile=/somewhere/to/dump/integrationcover.out DEVEL --config dendrite.yaml
-// Generate HTML with coverage: go tool cover -html=/somewhere/where/there/is/integrationcover.out -o cover.html
-// Source: https://dzone.com/articles/measuring-integration-test-coverage-rate-in-pouchc
-func TestMain(_ *testing.T) {
-	var (
-		args []string
-	)
-
-	for _, arg := range os.Args {
-		switch {
-		case strings.HasPrefix(arg, "DEVEL"):
-		case strings.HasPrefix(arg, "-test"):
-		default:
-			args = append(args, arg)
-		}
-	}
-	// only run the tests if there are args to be passed
-	if len(args) <= 1 {
-		return
-	}
-
-	waitCh := make(chan int, 1)
-	os.Args = args
-	go func() {
-		main()
-		close(waitCh)
-	}()
-
-	signalCh := make(chan os.Signal, 1)
-	signal.Notify(signalCh, syscall.SIGINT, syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGHUP)
-
-	select {
-	case <-signalCh:
-		return
-	case <-waitCh:
-		return
-	}
-}