Add options for specifying port and host of launched UI

README.md

@@ -98,7 +98,9 @@ decide to view it as a coll, and with that viewer selected, `deref` would
 return a list of pairs. Not many viewers implement this functionality
 currently, but expect more to do so in the future.
 
-### Themes
+### Options
+
+#### Themes
 
 There are currently three built-in themes:
 
@@ -113,6 +115,17 @@ Which can be passed as an option to `p/open`:
   {:portal.colors/theme :portal.colors/nord})
 ```
 
+#### Launcher
+
+By default, when `p/open` is called, an HTTP server is started on a randomly
+chosen port. To control this server's port and host, call the `p/start`
+function with the following options:
+
+| Option                  | Description                | If not specified     |
+|-------------------------|----------------------------|----------------------|
+| `:portal.launcher/port` | Port used to access UI     | random port selected |
+| `:portal.launcher/host` | Hostname used to access UI | "localhost"          |
+
 ## Datafy and Nav
 
 There is one exception to the behavior described above for the UI,

src/portal/api.cljc

@@ -9,6 +9,12 @@
   (add-tap #'rt/update-value)
   nil)
 
+(defn start
+  "Start the HTTP server with non-default options. Only use if you need
+  control over the HTTP server."
+  [options]
+  (l/start options))
+
 (defn open
   "Open a new inspector window."
   ([] (open nil))

src/portal/runtime/jvm/launcher.clj

@@ -35,17 +35,24 @@
    "--no-first-run"
    (str "--app=" url)])
 
+(defn start [options]
+  (when (nil? @server)
+    (let [{:portal.launcher/keys [port host] :or {port 0 host "localhost"}} options
+          http-server (http/run-server #'server/handler
+                                       {:port port
+                                        :max-ws (* 1024 1024 1024)
+                                        :legacy-return-value? false})]
+      (reset!
+       server
+       {:http-server http-server
+        :port (http/server-port http-server)
+        :host host}))))
+
 (defn open [options]
   (swap! rt/state merge {:portal/open? true} options)
-  (when (nil? @server)
-    (reset!
-     server
-     (http/run-server #'server/handler
-                      {:port 0
-                       :max-ws (* 1024 1024 1024)
-                       :legacy-return-value? false})))
   (let [session-id (random-uuid)
-        url (str "http://localhost:" (http/server-port @server) "?" session-id)]
+        {:keys [host port]} (or @server (start nil))
+        url (str "http://" host ":" port "?" session-id)]
     (if-let [bin (get-chrome-bin)]
       (let [flags (chrome-flags url)]
         (future (apply sh bin flags)))
@@ -54,5 +61,5 @@
 
 (defn close []
   (swap! rt/state assoc :portal/open? false)
-  (http/server-stop! @server)
+  (some-> server deref :http-server http/server-stop!)
   (reset! server nil))

src/portal/runtime/node/launcher.cljs

@@ -34,25 +34,32 @@
 
 (defonce ^:private server (atom nil))
 
-(defn- start [handler]
+(defn- create-server [handler port host]
   (js/Promise.
    (fn [resolve _reject]
      (let [server (http/createServer #(handler %1 %2))]
-       (.listen server 0
+       (.listen server port
                 #(let [port (.-port (.address server))
-                       result (with-meta {:server server} {:local-port port})]
+                       result {:http-server server
+                               :port port
+                               :host host}]
                    (resolve result)))))))
 
+(defn start [options]
+  (when (nil? @server)
+    (a/let [{:portal.launcher/keys [port host] :or {port 0 host "localhost"}} options
+            instance (create-server #'server/handler port host)]
+      (reset! server instance))))
+
 (defn- stop [handle]
-  (.close (:server handle)))
+  (some-> handle :http-server .close))
 
 (defn open [options]
   (let [session-id (random-uuid)]
     (swap! rt/state merge {:portal/open? true} options)
     (a/let [chrome-bin (get-chrome-bin)
-            instance   (or @server (start #'server/handler))
-            url        (str "http://localhost:" (-> instance meta :local-port) "?" session-id)]
-      (reset! server instance)
+            {:keys [host port]} (or @server (start nil))
+            url        (str "http://" host ":" port "?" session-id)]
       (if-not (some? chrome-bin)
         (println "Goto" url "to view portal ui.")
         (sh chrome-bin