[Audio] Connect to lavalink in the background (#2460)

Also:
- restart and reconnect if connection settings change
  - shutdown and restart if not configured to use external
- show a message in [p]play et al. when the connection hasn't been made
- move the JAR download to manager so audio.py can access it
- only start if no process exists
- bump red-lavalink to 0.2.3

Resolves #2306

Pipfile.lock

@@ -83,6 +83,13 @@
             ],
             "version": "==0.4.1"
         },
+        "distro": {
+            "hashes": [
+                "sha256:362dde65d846d23baee4b5c058c8586f219b5a54be1cf5fc6ff55c4578392f57",
+                "sha256:eedf82a470ebe7d010f1872c17237c79ab04097948800029994fa458e52fb4b4"
+            ],
+            "version": "==1.4.0"
+        },
         "dnspython": {
             "hashes": [
                 "sha256:36c5e8e38d4369a08b6780b7f27d790a292b2b08eea01607865bf0936c558e01",
@@ -254,10 +261,10 @@
         },
         "red-lavalink": {
             "hashes": [
-                "sha256:10a07b2b5736f52a0f5c3eeab3fbc3bf6a242ca6ee284a29ad79d6d1673ddfc3",
+                "sha256:13e1a3f91b990be9582cba039d9a32ec4cef760da1e7e6952143116ec83d4302",
-                "sha256:9df0ddaa92d0d7294a4e236c4069765a0b8e5f258c18075dedf28f4b64a1aab5"
+                "sha256:3dd0d73b4a908bbe9cfb703d2563dad1d1a58f8eea5896a0dacdf37d54a39d9c"
             ],
-            "version": "==0.2.1"
+            "version": "==0.2.3"
         },
         "schema": {
             "hashes": [
@@ -421,6 +428,13 @@
             ],
             "version": "==0.4.1"
         },
+        "distro": {
+            "hashes": [
+                "sha256:362dde65d846d23baee4b5c058c8586f219b5a54be1cf5fc6ff55c4578392f57",
+                "sha256:eedf82a470ebe7d010f1872c17237c79ab04097948800029994fa458e52fb4b4"
+            ],
+            "version": "==1.4.0"
+        },
         "docutils": {
             "hashes": [
                 "sha256:02aec4bd92ab067f6ff27a38a38a41173bf01bed8f89157768c1573f53e474a6",
@@ -664,10 +678,10 @@
         },
         "red-lavalink": {
             "hashes": [
-                "sha256:10a07b2b5736f52a0f5c3eeab3fbc3bf6a242ca6ee284a29ad79d6d1673ddfc3",
+                "sha256:13e1a3f91b990be9582cba039d9a32ec4cef760da1e7e6952143116ec83d4302",
-                "sha256:9df0ddaa92d0d7294a4e236c4069765a0b8e5f258c18075dedf28f4b64a1aab5"
+                "sha256:3dd0d73b4a908bbe9cfb703d2563dad1d1a58f8eea5896a0dacdf37d54a39d9c"
             ],
-            "version": "==0.2.1"
+            "version": "==0.2.3"
         },
         "requests": {
             "hashes": [

redbot/cogs/audio/__init__.py

@@ -1,10 +1,8 @@
 from pathlib import Path
-from aiohttp import ClientSession
-import shutil
 import logging
 
 from .audio import Audio
-from .manager import start_lavalink_server
+from .manager import start_lavalink_server, maybe_download_lavalink
 from redbot.core import commands
 from redbot.core.data_manager import cog_data_path
 import redbot.core
@@ -22,30 +20,6 @@ APP_YML_FILE = LAVALINK_DOWNLOAD_DIR / "application.yml"
 BUNDLED_APP_YML_FILE = Path(__file__).parent / "data/application.yml"
 
 
-async def download_lavalink(session):
-    with LAVALINK_JAR_FILE.open(mode="wb") as f:
-        async with session.get(LAVALINK_DOWNLOAD_URL) as resp:
-            while True:
-                chunk = await resp.content.read(512)
-                if not chunk:
-                    break
-                f.write(chunk)
-
-
-async def maybe_download_lavalink(loop, cog):
-    jar_exists = LAVALINK_JAR_FILE.exists()
-    current_build = redbot.VersionInfo.from_json(await cog.config.current_version())
-
-    if not jar_exists or current_build < redbot.core.version_info:
-        log.info("Downloading Lavalink.jar")
-        LAVALINK_DOWNLOAD_DIR.mkdir(parents=True, exist_ok=True)
-        async with ClientSession(loop=loop) as session:
-            await download_lavalink(session)
-        await cog.config.current_version.set(redbot.core.version_info.to_json())
-
-    shutil.copyfile(str(BUNDLED_APP_YML_FILE), str(APP_YML_FILE))
-
-
 async def setup(bot: commands.Bot):
     cog = Audio(bot)
     if not await cog.config.use_external_lavalink():

redbot/cogs/audio/audio.py

@@ -25,7 +25,7 @@ from redbot.core.utils.menus import (
 )
 from redbot.core.utils.predicates import MessagePredicate, ReactionPredicate
 from urllib.parse import urlparse
-from .manager import shutdown_lavalink_server
+from .manager import shutdown_lavalink_server, start_lavalink_server, maybe_download_lavalink
 
 _ = Translator("Audio", __file__)
 
@@ -74,26 +74,47 @@ class Audio(commands.Cog):
         self.config.register_global(**default_global)
         self.skip_votes = {}
         self.session = aiohttp.ClientSession()
+        self._connect_task = None
         self._disconnect_task = None
         self._cleaned_up = False
 
     async def initialize(self):
-        host = await self.config.host()
+        self._restart_connect()
-        password = await self.config.password()
+        self._disconnect_task = self.bot.loop.create_task(self.disconnect_timer())
-        rest_port = await self.config.rest_port()
-        ws_port = await self.config.ws_port()
-
-        await lavalink.initialize(
-            bot=self.bot,
-            host=host,
-            password=password,
-            rest_port=rest_port,
-            ws_port=ws_port,
-            timeout=60,
-        )
         lavalink.register_event_listener(self.event_handler)
 
-        self._disconnect_task = self.bot.loop.create_task(self.disconnect_timer())
+    def _restart_connect(self):
+        if self._connect_task:
+            self._connect_task.cancel()
+
+        self._connect_task = self.bot.loop.create_task(self.attempt_connect())
+
+    async def attempt_connect(self, timeout: int = 30):
+        while True:  # run until success
+            external = await self.config.use_external_lavalink()
+            if not external:
+                shutdown_lavalink_server()
+                await maybe_download_lavalink(self.bot.loop, self)
+                await start_lavalink_server(self.bot.loop)
+            try:
+                host = await self.config.host()
+                password = await self.config.password()
+                rest_port = await self.config.rest_port()
+                ws_port = await self.config.ws_port()
+
+                await lavalink.initialize(
+                    bot=self.bot,
+                    host=host,
+                    password=password,
+                    rest_port=rest_port,
+                    ws_port=ws_port,
+                    timeout=timeout,
+                )
+                return  # break infinite loop
+            except Exception:
+                if not external:
+                    shutdown_lavalink_server()
+                await asyncio.sleep(1)  # prevent busylooping
 
     async def event_handler(self, player, event_type, extra):
         notify = await self.config.guild(player.channel.guild).notify()
@@ -903,6 +924,10 @@ class Audio(commands.Cog):
                 player.store("connect", datetime.datetime.utcnow())
             except AttributeError:
                 return await self._embed_msg(ctx, _("Connect to a voice channel first."))
+            except IndexError:
+                return await self._embed_msg(
+                    ctx, _("Connection to Lavalink has not yet been established.")
+                )
         if dj_enabled:
             if not await self._can_instaskip(ctx, ctx.author):
                 return await self._embed_msg(ctx, _("You need the DJ role to queue tracks."))
@@ -1413,9 +1438,15 @@ class Audio(commands.Cog):
                 await lavalink.connect(ctx.author.voice.channel)
                 player = lavalink.get_player(ctx.guild.id)
                 player.store("connect", datetime.datetime.utcnow())
+            except IndexError:
+                await self._embed_msg(
+                    ctx, _("Connection to Lavalink has not yet been established.")
+                )
+                return False
             except AttributeError:
                 await self._embed_msg(ctx, _("Connect to a voice channel first."))
                 return False
+
         player = lavalink.get_player(ctx.guild.id)
         player.store("channel", ctx.channel.id)
         player.store("guild", ctx.guild.id)
@@ -1793,6 +1824,10 @@ class Audio(commands.Cog):
                 player.store("connect", datetime.datetime.utcnow())
             except AttributeError:
                 return await self._embed_msg(ctx, _("Connect to a voice channel first."))
+            except IndexError:
+                return await self._embed_msg(
+                    ctx, _("Connection to Lavalink has not yet been established.")
+                )
         player = lavalink.get_player(ctx.guild.id)
         shuffle = await self.config.guild(ctx.guild).shuffle()
         player.store("channel", ctx.channel.id)
@@ -1877,6 +1912,10 @@ class Audio(commands.Cog):
                 player.store("connect", datetime.datetime.utcnow())
             except AttributeError:
                 return await self._embed_msg(ctx, _("Connect to a voice channel first."))
+            except IndexError:
+                return await self._embed_msg(
+                    ctx, _("Connection to Lavalink has not yet been established.")
+                )
         player = lavalink.get_player(ctx.guild.id)
         jukebox_price = await self.config.guild(ctx.guild).jukebox_price()
         shuffle = await self.config.guild(ctx.guild).shuffle()
@@ -1897,7 +1936,6 @@ class Audio(commands.Cog):
         except IndexError:
             search_choice = tracks[-1]
         try:
-            search_check = search_choice.uri
             if "localtracks" in search_choice.uri:
                 if search_choice.title == "Unknown title":
                     description = "**{} - {}**\n{}".format(
@@ -2333,6 +2371,7 @@ class Audio(commands.Cog):
         """Toggle using external lavalink servers."""
         external = await self.config.use_external_lavalink()
         await self.config.use_external_lavalink.set(not external)
+
         if external:
             await self.config.host.set("localhost")
             await self.config.password.set("youshallnotpass")
@@ -2345,13 +2384,15 @@ class Audio(commands.Cog):
                 ),
             )
             embed.set_footer(text=_("Defaults reset."))
-            return await ctx.send(embed=embed)
+            await ctx.send(embed=embed)
         else:
             await self._embed_msg(
                 ctx,
                 _("External lavalink server: {true_or_false}.").format(true_or_false=not external),
             )
 
+        self._restart_connect()
+
     @llsetup.command()
     async def host(self, ctx, host):
         """Set the lavalink server host."""
@@ -2365,6 +2406,8 @@ class Audio(commands.Cog):
         else:
             await self._embed_msg(ctx, _("Host set to {host}.").format(host=host))
 
+        self._restart_connect()
+
     @llsetup.command()
     async def password(self, ctx, password):
         """Set the lavalink server password."""
@@ -2381,6 +2424,8 @@ class Audio(commands.Cog):
                 ctx, _("Server password set to {password}.").format(password=password)
             )
 
+        self._restart_connect()
+
     @llsetup.command()
     async def restport(self, ctx, rest_port: int):
         """Set the lavalink REST server port."""
@@ -2395,6 +2440,8 @@ class Audio(commands.Cog):
         else:
             await self._embed_msg(ctx, _("REST port set to {port}.").format(port=rest_port))
 
+        self._restart_connect()
+
     @llsetup.command()
     async def wsport(self, ctx, ws_port: int):
         """Set the lavalink websocket server port."""
@@ -2409,6 +2456,8 @@ class Audio(commands.Cog):
         else:
             await self._embed_msg(ctx, _("Websocket port set to {port}.").format(port=ws_port))
 
+        self._restart_connect()
+
     async def _check_external(self):
         external = await self.config.use_external_lavalink()
         if not external:
@@ -2555,7 +2604,7 @@ class Audio(commands.Cog):
         try:
             query_url = urlparse(url)
             return all([query_url.scheme, query_url.netloc, query_url.path])
-        except:
+        except Exception:
             return False
 
     @staticmethod
@@ -2659,8 +2708,13 @@ class Audio(commands.Cog):
     def __unload(self):
         if not self._cleaned_up:
             self.session.detach()
+
             if self._disconnect_task:
                 self._disconnect_task.cancel()
+
+            if self._connect_task:
+                self._connect_task.cancel()
+
             lavalink.unregister_event_listener(self.event_handler)
             self.bot.loop.create_task(lavalink.close())
             shutdown_lavalink_server()

redbot/cogs/audio/manager.py

@@ -8,6 +8,10 @@ import re
 from subprocess import Popen, DEVNULL
 from typing import Optional, Tuple
 
+from aiohttp import ClientSession
+
+import redbot.core
+
 _JavaVersion = Tuple[int, int]
 
 log = logging.getLogger("red.audio.manager")
@@ -111,6 +115,10 @@ async def start_lavalink_server(loop):
     start_cmd = "java {} -jar {}".format(extra_flags, LAVALINK_JAR_FILE.resolve())
 
     global proc
+
+    if proc and proc.poll() is None:
+        return  # already running
+
     proc = Popen(
         shlex.split(start_cmd, posix=os.name == "posix"),
         cwd=str(LAVALINK_DOWNLOAD_DIR),
@@ -126,11 +134,39 @@ async def start_lavalink_server(loop):
 
 
 def shutdown_lavalink_server():
-    log.info("Shutting down lavalink server.")
     global shutdown
     shutdown = True
     global proc
     if proc is not None:
+        log.info("Shutting down lavalink server.")
         proc.terminate()
         proc.wait()
         proc = None
+
+
+async def download_lavalink(session):
+    from . import LAVALINK_DOWNLOAD_URL, LAVALINK_JAR_FILE
+
+    with LAVALINK_JAR_FILE.open(mode="wb") as f:
+        async with session.get(LAVALINK_DOWNLOAD_URL) as resp:
+            while True:
+                chunk = await resp.content.read(512)
+                if not chunk:
+                    break
+                f.write(chunk)
+
+
+async def maybe_download_lavalink(loop, cog):
+    from . import LAVALINK_DOWNLOAD_DIR, LAVALINK_JAR_FILE, BUNDLED_APP_YML_FILE, APP_YML_FILE
+
+    jar_exists = LAVALINK_JAR_FILE.exists()
+    current_build = redbot.VersionInfo.from_json(await cog.config.current_version())
+
+    if not jar_exists or current_build < redbot.core.version_info:
+        log.info("Downloading Lavalink.jar")
+        LAVALINK_DOWNLOAD_DIR.mkdir(parents=True, exist_ok=True)
+        async with ClientSession(loop=loop) as session:
+            await download_lavalink(session)
+        await cog.config.current_version.set(redbot.core.version_info.to_json())
+
+    shutil.copyfile(str(BUNDLED_APP_YML_FILE), str(APP_YML_FILE))

setup.cfg

@@ -40,7 +40,7 @@ install_requires =
     multidict==4.5.2
     python-levenshtein-wheels==0.13.1
     pyyaml==3.13
-    red-lavalink==0.2.2
+    red-lavalink==0.2.3
     schema==0.6.8
     websockets==7.0
     yarl==1.3.0