Dockerize Heroku's Django Chat example

docker-compose.yml

version: '2'
services:
  postgres:
    image: postgres
    environment:
      - POSTGRES_PASSWORD=password

  redis:
    image: redis

  web:
    build: .
    command: daphne chat.asgi:channel_layer --port 8000 --bind 0.0.0.0 -v2
    ports:
      - 8000:8000
    links:
      - postgres
      - redis
    environment:
      - PYTHONUNBUFFERED=1
      - POSTGRES_HOST=postgres
      - POSTGRES_PASSWORD=password
      - REDIS_URL=redis://redis:6379

  worker:
    build: .
    command: python manage.py runworker -v2
    links:
      - postgres
      - redis
    environment:
      - PYTHONUNBUFFERED=1
      - POSTGRES_HOST=postgres
      - POSTGRES_PASSWORD=password
      - REDIS_URL=redis://redis:6379

Dockerfile

FROM python:2

RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

ADD requirements.txt /usr/src/app
RUN pip install --no-cache-dir -r requirements.txt

ADD . /usr/src/app

EXPOSE 8000
CMD ["python", "manage.py", "runworker", "-v2"]

dockerize.diff

commit 8522a682f93d3c3017435f0ff146d8ef85f51f64
Author: Tung Dao <me@tungdao.com>
Date:   Sun Mar 12 12:44:34 2017 +0700

    dockerize the app

diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..dab29ae
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,12 @@
+FROM python:2
+
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+ADD requirements.txt /usr/src/app
+RUN pip install --no-cache-dir -r requirements.txt
+
+ADD . /usr/src/app
+
+EXPOSE 8000
+CMD ["python", "manage.py", "runworker", "-v2"]
diff --git a/chat/settings.py b/chat/settings.py
index 6d7f2cf..91d374b 100644
--- a/chat/settings.py
+++ b/chat/settings.py
@@ -1,12 +1,12 @@
 import os
-import random
+import uuid
 import string
 import dj_database_url
 
 BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))
 
-SECRET_KEY = os.environ.get("SECRET_KEY", "".join(random.choice(string.printable) for i in range(40)))
+SECRET_KEY = os.environ.get("SECRET_KEY", uuid.uuid4())
 DEBUG = os.environ.get("DEBUG", False)
 
 # Application definition
@@ -55,7 +55,16 @@ TEMPLATES = (
 # https://docs.djangoproject.com/en/1.9/ref/settings/#databases
 
 DATABASES = {
-    'default': dj_database_url.config(default="postgres:///channels-example", conn_max_age=500)
+    # 'default': dj_database_url.config(default="postgres:///channels-example",
+    # conn_max_age=500)
+    'default': {
+        'ENGINE': 'django.db.backends.postgresql_psycopg2',
+        'NAME': os.environ.get('POSTGRES_DB', 'postgres'),
+        'USER': os.environ.get('POSTGRES_USER', 'postgres'),
+        'PASSWORD': os.environ.get('POSTGRES_PASSWORD'),
+        'HOST': os.environ.get('POSTGRES_HOST', 'localhost'),
+        'PORT': os.environ.get('POSTGRES_PORT', ''),
+    }
 }
 
 AUTH_PASSWORD_VALIDATORS = (
@@ -130,4 +139,4 @@ LOGGING = {
             'level': 'DEBUG',
         },
     },
-}
\ No newline at end of file
+}
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 0000000..092ddbd
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,35 @@
+version: '2'
+services:
+  postgres:
+    image: postgres
+    environment:
+      - POSTGRES_PASSWORD=password
+
+  redis:
+    image: redis
+
+  web:
+    build: .
+    command: daphne chat.asgi:channel_layer --port 8000 --bind 0.0.0.0 -v2
+    ports:
+      - 8000:8000
+    links:
+      - postgres
+      - redis
+    environment:
+      - PYTHONUNBUFFERED=1
+      - POSTGRES_HOST=postgres
+      - POSTGRES_PASSWORD=password
+      - REDIS_URL=redis://redis:6379
+
+  worker:
+    build: .
+    command: python manage.py runworker -v2
+    links:
+      - postgres
+      - redis
+    environment:
+      - PYTHONUNBUFFERED=1
+      - POSTGRES_HOST=postgres
+      - POSTGRES_PASSWORD=password
+      - REDIS_URL=redis://redis:6379