#4 add concierge app that implements the idea of tasks; rework rtmp to better handle multiple incoming streams; rework restream to create tasks

concierge/admin.py

@@ -0,0 +1,19 @@
+from django.contrib import admin
+from .models import Identity, Task, Claim
+
+
+class IdentityAdmin(admin.ModelAdmin):
+    fields = ['identity', 'name', 'notes', 'heartbeat']
+
+
+class TaskAdmin(admin.ModelAdmin):
+    fields = ['stream', 'type', 'configuration']
+
+
+class ClaimAdmin(admin.ModelAdmin):
+    fields = ['owner', 'task']
+
+
+admin.site.register(Identity, IdentityAdmin)
+admin.site.register(Task, TaskAdmin)
+admin.site.register(Claim, ClaimAdmin)

concierge/apps.py

@@ -0,0 +1,8 @@
+from django.apps import AppConfig
+
+
+class ConciergeConfig(AppConfig):
+    name = 'concierge'
+
+    def ready(self):
+        import concierge.signals  # noqa

concierge/migrations/0001_initial.py

@@ -0,0 +1,44 @@
+# Generated by Django 3.0.5 on 2020-04-26 17:25
+
+from django.db import migrations, models
+import django.db.models.deletion
+import uuid
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('rtmp', '0002_stream_publish_counter'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Identity',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('identity', models.CharField(default=uuid.uuid4, max_length=36, unique=True)),
+                ('name', models.CharField(max_length=100)),
+                ('notes', models.TextField()),
+                ('heartbeat', models.DateTimeField(blank=True)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Task',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('type', models.CharField(max_length=100)),
+                ('configuration', models.TextField()),
+                ('stream', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='rtmp.Stream')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Claim',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('owner', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='concierge.Identity')),
+                ('task', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='concierge.Task')),
+            ],
+        ),
+    ]

concierge/models.py

@@ -0,0 +1,28 @@
+import uuid
+from django.db import models
+from rtmp.models import Stream
+
+
+class Identity(models.Model):
+    # models a concierge identity. every running concierge needs to have a
+    # unique identity that is being used for task claims, etc.
+    identity = models.CharField(max_length=36, unique=True, default=uuid.uuid4)
+    name = models.CharField(max_length=100)
+    notes = models.TextField()
+
+    # heartbeat indicates last point in time that this identity was seen.
+    # some cronjob should scan the heartbeats and release all claims by
+    # identities that have not been seen in a while. this interval should
+    # be quite short so that the tasks can be claimed by other identities asap.
+    heartbeat = models.DateTimeField(blank=True)
+
+
+class Task(models.Model):
+    stream = models.ForeignKey(Stream, on_delete=models.CASCADE)
+    type = models.CharField(max_length=100)
+    configuration = models.TextField()
+
+
+class Claim(models.Model):
+    owner = models.ForeignKey(Identity, on_delete=models.CASCADE)
+    task = models.ForeignKey(Task, on_delete=models.CASCADE)

concierge/signals.py

@@ -0,0 +1,11 @@
+from django.dispatch import receiver
+from rtmp.signals import stream_inactive
+from .models import Task
+from rtmp.models import Stream
+
+
+@receiver(stream_inactive)
+def delete_tasks(sender, **kwargs):
+    # when a stream was unpublished, all related tasks need to be deleted.
+    stream = Stream.objects.get(stream=kwargs['stream'])
+    Task.objects.filter(stream=stream).delete()

concierge/tests.py

@@ -0,0 +1,3 @@
+from django.test import TestCase  # noqa
+
+# Create your tests here.

concierge/views.py

@@ -0,0 +1,3 @@
+from django.shortcuts import render  # noqa
+
+# Create your views here.

portier/settings.py

@@ -40,6 +40,7 @@ INSTALLED_APPS = [
     'fa',
     'portal.apps.PortalConfig',
     'rtmp.apps.RtmpConfig',
+    'concierge.apps.ConciergeConfig',
     'restream.apps.RestreamConfig',
 ]
 

restream/signals.py

@@ -1,31 +1,14 @@
-import logging
-
 from django.dispatch import receiver
-from rtmp.signals import on_publish, on_unpublish
-
-from portier.celery import app as celery
-
+from rtmp.signals import stream_active
 from .models import RestreamConfig
 from rtmp.models import Stream
-
-logger = logging.getLogger(__name__)
+from concierge.models import Task
 
 
-@receiver(on_unpublish)
-def callback_on_unpublish(sender, **kwargs):
-    logger.info("stop publish - {}".format(kwargs['name']))
-    celery.send_task('main.stop_restream', kwargs={'name': kwargs['name']})
-
-
-@receiver(on_publish)
-def callback_on_publish(sender, **kwargs):
-    logger.info("start publish - {}".format(kwargs['name']))
-    stream = Stream.objects.get(key=kwargs['stream'])
+@receiver(stream_active)
+def create_tasks(sender, **kwargs):
+    stream = Stream.objects.get(stream=kwargs['stream'])
     configs = RestreamConfig.objects.filter(stream=stream)
     for config in configs:
-        celery.send_task('main.start_restream', kwargs={
-            'app': kwargs['app'],
-            'stream': kwargs['stream'],
-            'target': config.target,
-            'id': config.id
-        })
+        task = Task(stream=stream, type='restream', configuration='{}')
+        task.save()

rtmp/admin.py

@@ -7,7 +7,7 @@ class ApplicationAdmin(admin.ModelAdmin):
 
 
 class StreamAdmin(admin.ModelAdmin):
-    fields = ['application', 'stream', 'name']
+    fields = ['application', 'stream', 'name', 'publish_counter']
 
 
 admin.site.register(Application, ApplicationAdmin)

rtmp/migrations/0002_stream_publish_counter.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.0.5 on 2020-04-26 17:25
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('rtmp', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='stream',
+            name='publish_counter',
+            field=models.PositiveIntegerField(default=0),
+        ),
+    ]

rtmp/models.py

@@ -17,21 +17,38 @@ class Stream(models.Model):
     stream = models.CharField(max_length=64, unique=True, default=uuid.uuid4)
     name = models.CharField(max_length=100)
 
+    # the same stream uuid can be published multiple times to different origin
+    # servers. this is a valid scheme to achieve a failover on the origin layer.
+    # thus we need to keep track if a stream is published at least once,
+    # and only send signals when we are going to / coming from 0 published streams.
+    publish_counter = models.PositiveIntegerField(default=0)
+
     def on_publish(self, param):
-        signals.on_publish.send(sender=self.__class__,
-                                name=self.name,
+        # if so far there were less than one incoming streams, this stream
+        # is now being considered active
+        if self.publish_counter < 1:
+            signals.stream_active.send(sender=self.__class__,
                                        stream=self.stream,
-                                app=str(self.application),
                                        param=param
                                        )
 
+        # keep track of this incoming stream
+        self.publish_counter += 1
+        self.save()
+
     def on_unpublish(self, param):
-        signals.on_unpublish.send(sender=self.__class__,
-                                  name=self.name,
+        # note that we now have on less incoming stream
+        if self.publish_counter > 0:
+            self.publish_counter -= 1
+
+        # if we now have less than one incoming stream, this stream is being
+        # considered inactive
+        if self.publish_counter < 1:
+            signals.stream_inactive.send(sender=self.__class__,
                                          stream=self.stream,
-                                  app=str(self.application),
                                          param=param
                                          )
+        self.save()
 
     def __str__(self):
         return self.name

rtmp/signals.py

@@ -1,4 +1,4 @@
 from django.dispatch import Signal
 
-on_publish = Signal(providing_args=['application', 'stream', 'params'])
-on_unpublish = Signal(providing_args=['application', 'stream', 'params'])
+stream_active = Signal(providing_args=['stream', 'params'])
+stream_inactive = Signal(providing_args=['stream', 'params'])