From e08a0fb8dce03061e04b568355acab741cc2544d Mon Sep 17 00:00:00 2001
From: Alexander Wang <alex@terrastruct.com>
Date: Wed, 16 Nov 2022 22:45:08 -0800
Subject: [PATCH] 2022-11-16 10:45:08PM

---
 ci/release/template/man/d2.1 | 12 +++++++++++-
 cmd/d2/main.go               |  6 ++++--
 cmd/d2/watch.go              | 19 ++++++-------------
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/ci/release/template/man/d2.1 b/ci/release/template/man/d2.1
index b9c680414..0583e90c3 100644
--- a/ci/release/template/man/d2.1
+++ b/ci/release/template/man/d2.1
@@ -36,12 +36,22 @@ See more docs, the source code and license at
 .It Fl w , -watch Ar false
 Watch for changes to input and live reload. Use
 .Ev $PORT and Ev $HOST to specify the listening address.
-.Ev $D2_PORT and $D2_HOST are also accepted and take priority. Default is localhost:0
+.It Fl h , -host Ar localhost
+Host listening address when used with
+.Ar watch
+.Ns .
+.It Fl p , -port Ar 0
+Port listening address when used with
+.Ar watch
+.Ns .
 .It Fl t , -theme Ar 0
 Set the diagram theme to the passed integer. For a list of available options, see
+.Lk https://oss.terrastruct.com/d2
+.Ns .
 .It Fl l , -layout Ar dagre
 Set the diagram layout engine to the passed string. For a list of available options, run
 .Ar layout
+.Ns .
 .It Fl b , -bundle Ar true
 Bundle all assets and layers into the output svg.
 .It Fl d , -debug
diff --git a/cmd/d2/main.go b/cmd/d2/main.go
index 6392541f4..cfca96ddf 100644
--- a/cmd/d2/main.go
+++ b/cmd/d2/main.go
@@ -32,10 +32,12 @@ func run(ctx context.Context, ms *xmain.State) (err error) {
 	ctx = xmain.DiscardSlog(ctx)
 
 	// These should be kept up-to-date with the d2 man page
-	watchFlag, err := ms.Opts.Bool("D2_WATCH", "watch", "w", false, "watch for changes to input and live reload. Use $HOST and $PORT to specify the listening address.\n$D2_HOST and $D2_PORT are also accepted and take priority (default localhost:0, which is will open on a randomly available local port).")
+	watchFlag, err := ms.Opts.Bool("D2_WATCH", "watch", "w", false, "watch for changes to input and live reload. Use $HOST and $PORT to specify the listening address.\n(default localhost:0, which is will open on a randomly available local port).")
 	if err != nil {
 		return xmain.UsageErrorf(err.Error())
 	}
+	hostFlag := ms.Opts.String("HOST", "host", "h", "localhost", "host listening address when used with watch")
+	portFlag := ms.Opts.String("PORT", "port", "p", "0", "port listening address when used with watch")
 	bundleFlag, err := ms.Opts.Bool("D2_BUNDLE", "bundle", "b", true, "bundle all assets and layers into the output svg.")
 	if err != nil {
 		return xmain.UsageErrorf(err.Error())
@@ -130,7 +132,7 @@ func run(ctx context.Context, ms *xmain.State) (err error) {
 			return xmain.UsageErrorf("-w[atch] cannot be combined with reading input from stdin")
 		}
 		ms.Env.Setenv("LOG_TIMESTAMPS", "1")
-		w, err := newWatcher(ctx, ms, plugin, *themeFlag, inputPath, outputPath)
+		w, err := newWatcher(ctx, ms, plugin, *themeFlag, *hostFlag, *portFlag, inputPath, outputPath)
 		if err != nil {
 			return err
 		}
diff --git a/cmd/d2/watch.go b/cmd/d2/watch.go
index 18dd9ea3c..a5d22c42c 100644
--- a/cmd/d2/watch.go
+++ b/cmd/d2/watch.go
@@ -43,6 +43,8 @@ type watcher struct {
 	ms           *xmain.State
 	layoutPlugin d2plugin.Plugin
 	themeID      int64
+	host         string
+	port         string
 	inputPath    string
 	outputPath   string
 
@@ -69,7 +71,7 @@ type compileResult struct {
 	SVG string `json:"svg"`
 }
 
-func newWatcher(ctx context.Context, ms *xmain.State, layoutPlugin d2plugin.Plugin, themeID int64, inputPath, outputPath string) (*watcher, error) {
+func newWatcher(ctx context.Context, ms *xmain.State, layoutPlugin d2plugin.Plugin, themeID int64, host, port, inputPath, outputPath string) (*watcher, error) {
 	ctx, cancel := context.WithCancel(ctx)
 
 	w := &watcher{
@@ -80,6 +82,8 @@ func newWatcher(ctx context.Context, ms *xmain.State, layoutPlugin d2plugin.Plug
 		ms:           ms,
 		layoutPlugin: layoutPlugin,
 		themeID:      themeID,
+		host:         host,
+		port:         port,
 		inputPath:    inputPath,
 		outputPath:   outputPath,
 
@@ -353,18 +357,7 @@ func (w *watcher) compileLoop(ctx context.Context) error {
 }
 
 func (w *watcher) listen() error {
-	host := "localhost"
-	port := "0"
-	hostEnv := w.ms.Env.Getenv("HOST")
-	if hostEnv != "" {
-		host = hostEnv
-	}
-	portEnv := w.ms.Env.Getenv("PORT")
-	if portEnv != "" {
-		port = portEnv
-	}
-
-	l, err := net.Listen("tcp", net.JoinHostPort(host, port))
+	l, err := net.Listen("tcp", net.JoinHostPort(w.host, w.port))
 	if err != nil {
 		return err
 	}