[FIX] main.py: re-implemented shutdown and restart (#19)

- This time we actually use exit codes, and rely on a wrapper
  to restart
- Addition of said wrapper script (run.sh) (from 0x5c/quick-bot-no-pain)
- Moved both commands to main.py

Fixes #4

cogs/basecog.py

@@ -10,7 +10,6 @@ General Public License, version 2.
 import discord
 import discord.ext.commands as commands
 
-import os
 
 class BaseCog(commands.Cog):
     def __init__(self, bot):
@@ -26,30 +25,6 @@ class BaseCog(commands.Cog):
         embed = embed.add_field(name="License", value=self.gs.info.license)
         await ctx.send(embed=embed)
 
-    @commands.command(name="restart")
-    async def _restart_bot(self, ctx):
-        """Restarts the bot."""
-        if ctx.author.id in self.gs.opt.owners_uids:
-            await ctx.message.add_reaction("✅")
-            await self.bot.logout()
-        else:
-            try:
-                await ctx.message.add_reaction("❌")
-            except:
-                return
-
-    @commands.command(name="shutdown")
-    async def _shutdown_bot(self, ctx):
-        """Shuts down the bot."""
-        if ctx.author.id in self.gs.opt.owners_uids:
-            await ctx.message.add_reaction("✅")
-            os._exit(42)
-        else:
-            try:
-                await ctx.message.add_reaction("❌")
-            except:
-                return
-
     @commands.command(name="ping")
     async def _ping(self, ctx):
         await ctx.send(f'**Pong!** Current ping is {self.bot.latency*1000:.1f} ms')

main.py

@@ -19,7 +19,9 @@ import options as opt
 import keys
 
 
-# --- Global settings ---
+# --- Settings ---
+
+exit_code = 1  # The default exit code. ?shutdown and ?restart will change it accordingly (fail-safe)
 
 debug_mode = opt.debug  # Separate assignement in-case we define an override (ternary operator goes here)
 
@@ -43,6 +45,34 @@ bot = commands.Bot(command_prefix=opt.prefix, description=info.description, help
 
 # --- Commands ---
 
+@bot.command(name="restart")
+async def _restart_bot(ctx):
+    """Restarts the bot."""
+    global exit_code
+    if ctx.author.id in opt.owners_uids:
+        await ctx.message.add_reaction("✅")
+        exit_code = 42  # Signals to the wrapper script that the bot needs to be restarted.
+        await bot.logout()
+    else:
+        try:
+            await ctx.message.add_reaction("❌")
+        except:
+            return
+
+@bot.command(name="shutdown")
+async def _shutdown_bot(ctx):
+    """Shuts down the bot."""
+    global exit_code
+    if ctx.author.id in opt.owners_uids:
+        await ctx.message.add_reaction("✅")
+        exit_code = 0  # Signals to the wrapper script that the bot should not be restarted.
+        await bot.logout()
+    else:
+        try:
+            await ctx.message.add_reaction("❌")
+        except:
+            return
+
 
 # --- Events ---
 
@@ -93,3 +123,12 @@ except ConnectionResetError as ex:  # More generic connection reset error
     if debug_mode:
         raise
     raise SystemExit("ConnectionResetError: {}".format(ex))
+
+
+# --- Exit ---
+# Codes for the wrapper shell script:
+# 0 - Clean exit, don't restart
+# 1 - Error exit, [restarting is up to the shell script]
+# 42 - Clean exit, do restart
+
+raise SystemExit(exit_code)

run.sh

@@ -0,0 +1,54 @@
+#!/bin/bash
+
+# A wrapper script for painless discord bots.
+# v1.0.0
+# Copyright (c) 2019 0x5c
+# Released under the terms of the MIT license.
+# Part of:
+# https://github.com/0x5c/quick-bot-no-pain
+
+
+# If $BOTENV is not defined, default to 'botenv'
+if [[ -z ${BOTENV+x} ]]; then
+    BOTENV='botenv'
+fi
+
+# Argument handling     # ? TODO: Argument passing ?
+if [[ $1 == '--pass-errors' ]]; then 
+    _PASS_ERRORS=1
+fi
+
+
+# A function called when the bot exits to decide what to do
+code_handling() {
+    case $err in
+        0)
+            echo "$_message: exiting"
+            exit 0      # The bot whishes to stay alone.
+            ;;
+        42)
+            echo "$_message: restarting"
+            return      # The bot whishes to be restarted (returns to the loop).
+            ;;
+        *)
+            if [[ $_PASS_ERRORS -eq 0 ]]; then    # The bot crashed and:
+                echo "$_message: restarting"
+                return      # ...we should return to the loop to restart it.
+            else
+                echo "$_message: exiting (--pass-errors)"
+                exit $err   # ...we should just exit and pass the code to our parent (probably a daemon/service manager).
+            fi
+            ;;
+    esac
+}
+
+
+echo "$0: Starting bot..."
+
+# The loop
+while true; do
+    ./$BOTENV/bin/python3 main.py
+    err=$?
+    _message="$0: The bot exited with [$err]"
+    code_handling
+done