Refactor proc into procgroup (#779)

This PR is prepping for when locally we run multiple processes of the
Encore application, one for each microservice and one for each gateway.

This starts by refactoring our existing `Proc` struct into `ProcGroup`
while keeping most of the API the same.

Then within a ProcGroup we introduce the concept of `Proc`'s which can
be started independently of each other.

cli/daemon/dash/dash.go

@@ -121,7 +121,7 @@ func (h *handler) Handle(ctx context.Context, reply jsonrpc2.Replier, r jsonrpc2
 		if run == nil {
 			return reply(ctx, map[string]interface{}{"running": false}, nil)
 		}
-		proc := run.Proc()
+		proc := run.ProcGroup()
 		if proc == nil {
 			return reply(ctx, map[string]interface{}{"running": false}, nil)
 		}
@@ -192,7 +192,7 @@ func (h *handler) apiCall(ctx context.Context, reply jsonrpc2.Replier, p *apiCal
 		log.Error().Str("app_id", p.AppID).Msg("dash: cannot make api call: app not running")
 		return reply(ctx, nil, fmt.Errorf("app not running"))
 	}
-	proc := run.Proc()
+	proc := run.ProcGroup()
 	if proc == nil {
 		log.Error().Str("app_id", p.AppID).Msg("dash: cannot make api call: app not running")
 		return reply(ctx, nil, fmt.Errorf("app not running"))
@@ -272,7 +272,7 @@ var _ run.EventListener = (*Server)(nil)
 // OnStart notifies active websocket clients about the started run.
 func (s *Server) OnStart(r *run.Run) {
 	m := &jsonpb.Marshaler{OrigName: true, EmitDefaults: true}
-	proc := r.Proc()
+	proc := r.ProcGroup()
 	str, err := m.MarshalToString(proc.Meta)
 	if err != nil {
 		log.Error().Err(err).Msg("dash: could not marshal app meta")
@@ -295,7 +295,7 @@ func (s *Server) OnStart(r *run.Run) {
 // OnReload notifies active websocket clients about the reloaded run.
 func (s *Server) OnReload(r *run.Run) {
 	m := &jsonpb.Marshaler{OrigName: true, EmitDefaults: true}
-	proc := r.Proc()
+	proc := r.ProcGroup()
 	str, err := m.MarshalToString(proc.Meta)
 	if err != nil {
 		log.Error().Err(err).Msg("dash: could not marshal app meta")

cli/daemon/run.go

@@ -143,7 +143,7 @@ func (s *Server) Run(req *daemonpb.RunRequest, stream daemonpb.Daemon_RunServer)
 	ops.AllDone()
 
 	stderr.Write([]byte("\n"))
-	pid := runInstance.Proc().Pid
+	pid := runInstance.ProcGroup().Gateway.Pid
 	fmt.Fprintf(stderr, "  Encore development server running!\n\n")
 
 	fmt.Fprintf(stderr, "  Your API is running at:     %s\n", aurora.Cyan("http://"+runInstance.ListenAddr))
@@ -153,7 +153,7 @@ func (s *Server) Run(req *daemonpb.RunRequest, stream daemonpb.Daemon_RunServer)
 		fmt.Fprintf(stderr, "  Process ID:                 %d\n", aurora.Cyan(pid))
 	}
 	// Log which experiments are enabled, if any
-	if exp := runInstance.Proc().Experiments.List(); len(exp) > 0 {
+	if exp := runInstance.ProcGroup().Experiments.List(); len(exp) > 0 {
 		strs := make([]string, len(exp))
 		for i, e := range exp {
 			strs[i] = string(e)
@@ -189,7 +189,7 @@ func (s *Server) Run(req *daemonpb.RunRequest, stream daemonpb.Daemon_RunServer)
 		case <-runInstance.Done():
 			return
 		case <-time.After(5 * time.Second):
-			if proc := runInstance.Proc(); proc != nil {
+			if proc := runInstance.ProcGroup(); proc != nil {
 				showFirstRunExperience(runInstance, proc.Meta, stderr)
 			}
 		}

cli/daemon/run/http.go

@@ -28,16 +28,16 @@ func (r *Run) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		}
 	}
 
-	proc := r.proc.Load().(*Proc)
+	proc := r.proc.Load().(*ProcGroup)
 	proc.forwardReq(endpoint, w, req)
 }
 
 // forwardReq forwards the request to the Encore app.
-func (p *Proc) forwardReq(endpoint string, w http.ResponseWriter, req *http.Request) {
+func (pg *ProcGroup) forwardReq(endpoint string, w http.ResponseWriter, req *http.Request) {
 	// director is a simplified version from httputil.NewSingleHostReverseProxy.
 	director := func(r *http.Request) {
 		r.URL.Scheme = "http"
-		r.URL.Host = p.Run.ListenAddr
+		r.URL.Host = pg.Run.ListenAddr
 		r.URL.Path = "/" + endpoint
 		r.URL.RawQuery = req.URL.RawQuery
 		if _, ok := r.Header["User-Agent"]; !ok {
@@ -47,7 +47,7 @@ func (p *Proc) forwardReq(endpoint string, w http.ResponseWriter, req *http.Requ
 
 		// Add the auth key unless the test header is set.
 		if r.Header.Get(TestHeaderDisablePlatformAuth) == "" {
-			addAuthKeyToRequest(r, p.authKey)
+			addAuthKeyToRequest(r, pg.authKey)
 		}
 	}
 
@@ -57,7 +57,7 @@ func (p *Proc) forwardReq(endpoint string, w http.ResponseWriter, req *http.Requ
 	transport := &http.Transport{
 		DisableKeepAlives: true,
 		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-			return p.Client.Open()
+			return pg.Gateway.Client.Open()
 		},
 	}
 

cli/daemon/run/manager.go

@@ -51,11 +51,11 @@ type EventListener interface {
 
 // FindProc finds the proc with the given id.
 // It reports nil if no such proc was found.
-func (mgr *Manager) FindProc(procID string) *Proc {
+func (mgr *Manager) FindProc(procID string) *ProcGroup {
 	mgr.mu.Lock()
 	defer mgr.mu.Unlock()
 	for _, run := range mgr.runs {
-		if p := run.Proc(); p != nil && p.ID == procID {
+		if p := run.ProcGroup(); p != nil && p.ID == procID {
 			return p
 		}
 	}