feat: setup TURN server

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## untagged
 
+- Setup TURN server
+  ([#621](https://github.com/chatmail/relay/pull/621))
+
 - Update iroh-relay to 0.35.0
   ([#650](https://github.com/chatmail/relay/pull/650))
 

chatmaild/pyproject.toml

@@ -29,6 +29,7 @@ echobot = "chatmaild.echo:main"
 chatmail-metrics = "chatmaild.metrics:main"
 delete_inactive_users = "chatmaild.delete_inactive_users:main"
 lastlogin = "chatmaild.lastlogin:main"
+turnserver = "chatmaild.turnserver:main"
 
 [project.entry-points.pytest11]
 "chatmaild.testplugin" = "chatmaild.tests.plugin"

chatmaild/src/chatmaild/metadata.py

@@ -7,6 +7,7 @@ from .config import read_config
 from .dictproxy import DictProxy
 from .filedict import FileDict
 from .notifier import Notifier
+from .turnserver import turn_credentials
 
 
 def _is_valid_token_timestamp(timestamp, now):
@@ -75,11 +76,12 @@ class Metadata:
 
 
 class MetadataDictProxy(DictProxy):
-    def __init__(self, notifier, metadata, iroh_relay=None):
+    def __init__(self, notifier, metadata, iroh_relay=None, turn_hostname=None):
         super().__init__()
         self.notifier = notifier
         self.metadata = metadata
         self.iroh_relay = iroh_relay
+        self.turn_hostname = turn_hostname
 
     def handle_lookup(self, parts):
         # Lpriv/43f5f508a7ea0366dff30200c15250e3/devicetoken\tlkj123poi@c2.testrun.org
@@ -98,6 +100,11 @@ class MetadataDictProxy(DictProxy):
             ):
                 # Handle `GETMETADATA "" /shared/vendor/deltachat/irohrelay`
                 return f"O{self.iroh_relay}\n"
+            elif keyname == "vendor/vendor.dovecot/pvt/server/vendor/deltachat/turn":
+                res = turn_credentials()
+                port = 3478
+                return f"O{self.turn_hostname}:{port}:{res}\n"
+
         logging.warning(f"lookup ignored: {parts!r}")
         return "N\n"
 
@@ -121,6 +128,7 @@ def main():
 
     config = read_config(config_path)
     iroh_relay = config.iroh_relay
+    mail_domain = config.mail_domain
 
     vmail_dir = config.mailboxes_dir
     if not vmail_dir.exists():
@@ -134,7 +142,10 @@ def main():
     notifier.start_notification_threads(metadata.remove_token_from_addr)
 
     dictproxy = MetadataDictProxy(
-        notifier=notifier, metadata=metadata, iroh_relay=iroh_relay
+        notifier=notifier,
+        metadata=metadata,
+        iroh_relay=iroh_relay,
+        turn_hostname=mail_domain,
     )
 
     dictproxy.serve_forever_from_socket(socket)

chatmaild/src/chatmaild/turnserver.py

@@ -0,0 +1,9 @@
+#!/usr/bin/env python3
+import socket
+
+
+def turn_credentials() -> str:
+    with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as client_socket:
+        client_socket.connect("/run/chatmail-turn/turn.socket")
+        with client_socket.makefile("rb") as file:
+            return file.readline().decode("utf-8")

cmdeploy/src/cmdeploy/__init__.py

@@ -128,6 +128,7 @@ def _install_remote_venv_with_chatmaild(config) -> None:
         "echobot",
         "chatmail-metadata",
         "lastlogin",
+        "turnserver",
     ):
         execpath = fn if fn != "filtermail-incoming" else "filtermail"
         params = dict(
@@ -497,6 +498,56 @@ def check_config(config):
     return config
 
 
+def deploy_turn_server(config):
+    (url, sha256sum) = {
+        "x86_64": (
+            "https://github.com/chatmail/chatmail-turn/releases/download/v0.3/chatmail-turn-x86_64-linux",
+            "841e527c15fdc2940b0469e206188ea8f0af48533be12ecb8098520f813d41e4",
+        ),
+        "aarch64": (
+            "https://github.com/chatmail/chatmail-turn/releases/download/v0.3/chatmail-turn-aarch64-linux",
+            "a5fc2d06d937b56a34e098d2cd72a82d3e89967518d159bf246dc69b65e81b42",
+        ),
+    }[host.get_fact(facts.server.Arch)]
+
+    need_restart = False
+
+    existing_sha256sum = host.get_fact(Sha256File, "/usr/local/bin/chatmail-turn")
+    if existing_sha256sum != sha256sum:
+        server.shell(
+            name="Download chatmail-turn",
+            commands=[
+                f"(curl -L {url} >/usr/local/bin/chatmail-turn.new && (echo '{sha256sum} /usr/local/bin/chatmail-turn.new' | sha256sum -c) && mv /usr/local/bin/chatmail-turn.new /usr/local/bin/chatmail-turn)",
+                "chmod 755 /usr/local/bin/chatmail-turn",
+            ],
+        )
+        need_restart = True
+
+    source_path = importlib.resources.files(__package__).joinpath(
+        "service", "turnserver.service.f"
+    )
+    content = source_path.read_text().format(mail_domain=config.mail_domain).encode()
+
+    systemd_unit = files.put(
+        name="Upload turnserver.service",
+        src=io.BytesIO(content),
+        dest="/etc/systemd/system/turnserver.service",
+        user="root",
+        group="root",
+        mode="644",
+    )
+    need_restart |= systemd_unit.changed
+
+    systemd.service(
+        name="Setup turnserver service",
+        service="turnserver.service",
+        running=True,
+        enabled=True,
+        restarted=need_restart,
+        daemon_reload=systemd_unit.changed,
+    )
+
+
 def deploy_mtail(config):
     # Uninstall mtail package, we are going to install a static binary.
     apt.packages(name="Uninstall mtail", packages=["mtail"], present=False)
@@ -673,6 +724,8 @@ def deploy_chatmail(config_path: Path, disable_mail: bool) -> None:
         packages=["rsync"],
     )
 
+    deploy_turn_server(config)
+
     # Run local DNS resolver `unbound`.
     # `resolvconf` takes care of setting up /etc/resolv.conf
     # to use 127.0.0.1 as the resolver.

cmdeploy/src/cmdeploy/iroh-relay.toml

@@ -1,5 +1,11 @@
 enable_relay = true
 http_bind_addr = "[::]:3340"
-enable_stun = true
+
+# Disable built-in STUN server in iroh-relay 0.35
+# as we deploy our own TURN server instead.
+# STUN server is going to be removed in iroh-relay 1.0
+# and this line can be removed after upgrade.
+enable_stun = false
+
 enable_metrics = false
 metrics_bind_addr = "127.0.0.1:9092"

cmdeploy/src/cmdeploy/service/turnserver.service.f

@@ -0,0 +1,16 @@
+[Unit]
+Description=A wrapper for the TURN server
+After=network.target
+
+[Service]
+Type=simple
+Restart=always
+ExecStart=/usr/local/bin/chatmail-turn --realm {mail_domain} --socket /run/chatmail-turn/turn.socket
+
+# Create /run/chatmail-turn
+RuntimeDirectory=chatmail-turn
+User=vmail
+Group=vmail
+
+[Install]
+WantedBy=multi-user.target