Add flatpak support to the browser addon (#5200)

CHANGELOG.md

@@ -51,6 +51,7 @@
 * Exit early if there are errors on startup (#4544, @mhils)
 * Fixed encoding guessing: only search for meta tags in HTML bodies (##4566, @Prinzhorn)
 * Binaries are now built with Python 3.10 (@mhils)
+* Add flatpak support to the browser addon (@pauloromeira)
 
 ## 28 September 2021: mitmproxy 7.0.4
 

mitmproxy/addons/browser.py

@@ -23,6 +23,34 @@ def get_chrome_executable() -> typing.Optional[str]:
     ):
         if shutil.which(browser):
             return browser
+
+    return None
+
+
+def get_chrome_flatpak() -> typing.Optional[str]:
+    if shutil.which("flatpak"):
+        for browser in (
+            "com.google.Chrome",
+            "org.chromium.Chromium",
+            "com.github.Eloston.UngoogledChromium",
+            "com.google.ChromeDev",
+        ):
+            if subprocess.run(
+                ["flatpak", "info", browser],
+                stdout=subprocess.DEVNULL,
+                stderr=subprocess.DEVNULL,
+            ).returncode == 0:
+                return browser
+
+    return None
+
+
+def get_browser_cmd() -> typing.Optional[typing.List[str]]:
+    if browser := get_chrome_executable():
+        return [browser]
+    elif browser := get_chrome_flatpak():
+        return ["flatpak", "run", "-p", browser]
+
     return None
 
 
@@ -39,7 +67,7 @@ class Browser:
         if len(self.browser) > 0:
             ctx.log.alert("Starting additional browser")
 
-        cmd = get_chrome_executable()
+        cmd = get_browser_cmd()
         if not cmd:
             ctx.log.alert("Your platform is not supported yet - please submit a patch.")
             return
@@ -48,7 +76,7 @@ class Browser:
         self.tdir.append(tdir)
         self.browser.append(subprocess.Popen(
             [
-                cmd,
+                *cmd,
                 "--user-data-dir=%s" % str(tdir.name),
                 "--proxy-server={}:{}".format(
                     ctx.options.listen_host or "127.0.0.1",
@@ -61,8 +89,8 @@ class Browser:
 
                 "about:blank",
             ],
-            stdout = subprocess.DEVNULL,
+            stdout=subprocess.DEVNULL,
-            stderr = subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
         ))
 
     def done(self):

test/mitmproxy/addons/test_browser.py

@@ -27,3 +27,33 @@ async def test_no_browser():
         with taddons.context() as tctx:
             b.start()
             await tctx.master.await_log("platform is not supported")
+
+
+async def test_get_browser_cmd_executable():
+    with mock.patch("shutil.which") as which:
+        which.side_effect = lambda cmd: cmd == "chrome"
+        assert browser.get_browser_cmd() == ["chrome"]
+
+
+async def test_get_browser_cmd_no_executable():
+    with mock.patch("shutil.which") as which:
+        which.return_value = False
+        assert browser.get_browser_cmd() is None
+
+
+async def test_get_browser_cmd_flatpak():
+    def subprocess_run_mock(cmd, **kwargs):
+        returncode = 0 if cmd == ["flatpak", "info", "com.google.Chrome"] else 1
+        return mock.Mock(returncode=returncode)
+
+    with mock.patch("shutil.which") as which, mock.patch("subprocess.run") as subprocess_run:
+        which.side_effect = lambda cmd: cmd == "flatpak"
+        subprocess_run.side_effect = subprocess_run_mock
+        assert browser.get_browser_cmd() == ["flatpak", "run", "-p", "com.google.Chrome"]
+
+
+async def test_get_browser_cmd_no_flatpak():
+    with mock.patch("shutil.which") as which, mock.patch("subprocess.run") as subprocess_run:
+        which.side_effect = lambda cmd: cmd == "flatpak"
+        subprocess_run.return_value = mock.Mock(returncode=1)
+        assert browser.get_browser_cmd() is None