Allow browser.start to open multiple browsers. (#4585)

CHANGELOG.md

@@ -58,6 +58,8 @@ If you depend on these features, please raise your voice in
 * Add option `export_preserve_original_ip` to force exported command to connect to IP from original request. Only supports curl at the moment. (@dkasak)
 * Major proxy protocol testing (@r00t-)
 * Switch Docker image release to be based on Debian (@PeterDaveHello)
+* Multiple Browsers: The `browser.start` command may be executed more than once to start additional
+  browser sessions. (@rbdixon)
 * --- TODO: add new PRs above this line ---
 * ... and various other fixes, documentation improvements, dependency version bumps, etc.
 

mitmproxy/addons/browser.py

@@ -27,8 +27,8 @@ def get_chrome_executable() -> typing.Optional[str]:
 
 
 class Browser:
-    browser = None
-    tdir = None
+    browser: typing.List[subprocess.Popen] = []
+    tdir: typing.List[tempfile.TemporaryDirectory] = []
 
     @command.command("browser.start")
     def start(self) -> None:
@@ -36,23 +36,20 @@ class Browser:
             Start an isolated instance of Chrome that points to the currently
             running proxy.
         """
-        if self.browser:
-            if self.browser.poll() is None:
-                ctx.log.alert("Browser already running")
-                return
-            else:
-                self.done()
+        if len(self.browser) > 0:
+            ctx.log.alert("Starting additional browser")
 
         cmd = get_chrome_executable()
         if not cmd:
             ctx.log.alert("Your platform is not supported yet - please submit a patch.")
             return
 
-        self.tdir = tempfile.TemporaryDirectory()
-        self.browser = subprocess.Popen(
+        tdir = tempfile.TemporaryDirectory()
+        self.tdir.append(tdir)
+        self.browser.append(subprocess.Popen(
             [
                 cmd,
-                "--user-data-dir=%s" % str(self.tdir.name),
+                "--user-data-dir=%s" % str(tdir.name),
                 "--proxy-server={}:{}".format(
                     ctx.options.listen_host or "127.0.0.1",
                     ctx.options.listen_port
@@ -66,11 +63,12 @@ class Browser:
             ],
             stdout = subprocess.DEVNULL,
             stderr = subprocess.DEVNULL,
-        )
+        ))
 
     def done(self):
-        if self.browser:
-            self.browser.kill()
-            self.tdir.cleanup()
-        self.browser = None
-        self.tdir = None
+        for browser in self.browser:
+            browser.kill()
+        for tdir in self.tdir:
+            tdir.cleanup()
+        self.browser = []
+        self.tdir = []

test/mitmproxy/addons/test_browser.py

@@ -15,9 +15,8 @@ async def test_browser():
             assert po.called
 
             b.start()
-            b.browser.poll = lambda: None
-            b.start()
-            await tctx.master.await_log("already running")
+            await tctx.master.await_log("Starting additional browser")
+            assert len(b.browser) == 2
             b.done()
             assert not b.browser