Load settings from environment variables. Fixes #187

CHANGELOG.md

@@ -1,6 +1,12 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## Unreleased
+
+### Improvements
+- Load settings from environment variables
+
+
 ## 1.2.0 - 2018-10-20
 
 ### Improvements

README.md

@@ -76,10 +76,54 @@ visit `http://localhost:8080/admin`
 
 ## Configuration
 
-Site configuration is kept in `hc/settings.py`. Additional configuration
-is loaded from `hc/local_settings.py` file, if it exists. You
-can create this file (should be right next to `settings.py` in the filesystem)
-and override settings as needed.
+Site configuration is loaded from environment variables. This is
+done in `hc/settings.py`. Additional configuration is loaded
+from `hc/local_settings.py` file, if it exists. You can create this file
+(should be right next to `settings.py` in the filesystem) and override
+settings, or add extra settings as needed.
+
+Configurations settings loaded from environment variables:
+
+| Environment variable | Default value | Notes
+| -------------------- | ------------- | ----- |
+| [SECRET_KEY](https://docs.djangoproject.com/en/2.1/ref/settings/#secret-key) | `"---"`
+| [DEBUG](https://docs.djangoproject.com/en/2.1/ref/settings/#debug) | `True` | Set to `False` for production
+| [ALLOWED_HOSTS](https://docs.djangoproject.com/en/2.1/ref/settings/#allowed-hosts) | `*` | Separate multiple hosts with commas
+| [DEFAULT_FROM_EMAIL](https://docs.djangoproject.com/en/2.1/ref/settings/#default-from-email) | `"[email protected]"`
+| USE_PAYMENTS | `False`
+| REGISTRATION_OPEN | `True`
+| DB | `"sqlite"` | Set to `"postgres"` or `"mysql"`
+| [DB_HOST](https://docs.djangoproject.com/en/2.1/ref/settings/#host) | `""` *(empty string)*
+| [DB_PORT](https://docs.djangoproject.com/en/2.1/ref/settings/#port) | `""` *(empty string)*
+| [DB_NAME](https://docs.djangoproject.com/en/2.1/ref/settings/#name) | `"hc"`
+| [DB_USER](https://docs.djangoproject.com/en/2.1/ref/settings/#user) | `"postgres"` or `"root"`
+| [DB_PASSWORD](https://docs.djangoproject.com/en/2.1/ref/settings/#password) | `""` *(empty string)*
+| [DB_CONN_MAX_AGE](https://docs.djangoproject.com/en/2.1/ref/settings/#conn-max-age) | `0`
+| DB_SSLMODE | `"prefer"` | PostgreSQL-specific, [details](https://blog.github.com/2018-10-21-october21-incident-report/)
+| DB_TARGET_SESSION_ATTRS | `"read-write"` | PostgreSQL-specific, [details](https://www.postgresql.org/docs/10/static/libpq-connect.html#LIBPQ-CONNECT-TARGET-SESSION-ATTRS)
+| SITE_ROOT | `"http://localhost:8000"`
+| SITE_NAME | `"Mychecks"`
+| MASTER_BADGE_LABEL | `"Mychecks"`
+| PING_ENDPOINT | `"http://localhost:8000/ping/"`
+| PING_EMAIL_DOMAIN | `"localhost"`
+| DISCORD_CLIENT_ID | `None`
+| DISCORD_CLIENT_SECRET | `None`
+| SLACK_CLIENT_ID | `None`
+| SLACK_CLIENT_SECRET | `None`
+| PUSHOVER_API_TOKEN | `None`
+| PUSHOVER_SUBSCRIPTION_URL | `None`
+| PUSHOVER_EMERGENCY_RETRY_DELAY | `300`
+| PUSHOVER_EMERGENCY_EXPIRATION | `86400`
+| PUSHBULLET_CLIENT_ID | `None`
+| PUSHBULLET_CLIENT_SECRET | `None`
+| TELEGRAM_BOT_NAME | `"ExampleBot"`
+| TELEGRAM_TOKEN | `None`
+| TWILIO_ACCOUNT | `None`
+| TWILIO_AUTH | `None`
+| TWILIO_FROM | `None`
+| PD_VENDOR_KEY | `None`
+| TRELLO_APP_KEY | `None`
+
 
 Some useful settings keys to override are:
 
@@ -109,10 +153,9 @@ to your team account.
 
 ## Database Configuration
 
-Database configuration is stored in `hc/settings.py` and can be overriden
-in `hc/local_settings.py`. The default database engine is SQLite. To use
-PostgreSQL, create `hc/local_settings.py` if it does not exist, and put the
-following in it, changing it as neccessary:
+Database configuration is loaded from environment variables. If you
+need to use a non-standard configuration, you can override the
+database configuration in `hc/local_settings.py` like so:
 
 ```python
 DATABASES = {
@@ -121,38 +164,10 @@ DATABASES = {
         'NAME':     'your-database-name-here',
         'USER':     'your-database-user-here',
         'PASSWORD': 'your-database-password-here',
-        'TEST': {'CHARSET': 'UTF8'}
-    }
-}
-```
-
-For MySQL:
-
-```python
-DATABASES = {
-    'default': {
-        'ENGINE':   'django.db.backends.mysql',
-        'NAME':     'your-database-name-here',
-        'USER':     'your-database-user-here',
-        'PASSWORD': 'your-database-password-here',
-        'TEST': {'CHARSET': 'UTF8'}
-    }
-}
-```
-
-You can also use `hc/local_settings.py` to read database
-configuration from environment variables like so:
-
-```python
-import os
-
-DATABASES = {
-    'default': {
-        'ENGINE':   os.environ['DB_ENGINE'],
-        'NAME':     os.environ['DB_NAME'],
-        'USER':     os.environ['DB_USER'],
-        'PASSWORD': os.environ['DB_PASSWORD'],
-        'TEST': {'CHARSET': 'UTF8'}
+        'TEST': {'CHARSET': 'UTF8'},
+        'OPTIONS': {
+            ... your custom options here ...
+        }
     }
 }
 ```
@@ -262,9 +277,9 @@ To enable Discord integration, you will need to:
   `SITE_ROOT/integrations/add_discord/`. For example, if you are running a
   development server on `localhost:8000` then the redirect URI would be
   `http://localhost:8000/integrations/add_discord/`
-* Look up your Discord app's Client ID and Client Secret. Add them
-  to your `hc/local_settings.py` file as `DISCORD_CLIENT_ID` and
-  `DISCORD_CLIENT_SECRET` fields.
+* Look up your Discord app's Client ID and Client Secret. Put them
+  in `DISCORD_CLIENT_ID` and `DISCORD_CLIENT_SECRET` environment
+  variables.
 
 
 ### Pushover
@@ -274,17 +289,17 @@ To enable Pushover integration, you will need to:
 * register a new application on https://pushover.net/apps/build
 * enable subscriptions in your application and make sure to enable the URL
   subscription type
-* add the application token and subscription URL to `hc/local_settings.py`, as
-  `PUSHOVER_API_TOKEN` and `PUSHOVER_SUBSCRIPTION_URL`
+* put the application token and the subscription URL in
+  `PUSHOVER_API_TOKEN` and `PUSHOVER_SUBSCRIPTION_URL` environment
+  variables
 
 ### Telegram
 
 * Create a Telegram bot by talking to the
 [BotFather](https://core.telegram.org/bots#6-botfather). Set the bot's name,
 description, user picture, and add a "/start" command.
-* After creating the bot you will have the bot's name and token. Add them
-to your `hc/local_settings.py` file as `TELEGRAM_BOT_NAME` and
-`TELEGRAM_TOKEN` fields.
+* After creating the bot you will have the bot's name and token. Put them
+in `TELEGRAM_BOT_NAME` and `TELEGRAM_TOKEN` environment variables.
 * Run `settelegramwebhook` management command. This command tells Telegram
 where to forward channel messages by invoking Telegram's
 [setWebhook](https://core.telegram.org/bots/api#setwebhook) API call:

hc/settings.py

@@ -1,13 +1,8 @@
 """
-Django settings for hc project.
-
-Generated by 'django-admin startproject' using Django 1.8.2.
-
-For more information on this file, see
-https://docs.djangoproject.com/en/1.8/topics/settings/
+Django settings for healthchecks project.
 
 For the full list of settings and their values, see
-https://docs.djangoproject.com/en/1.8/ref/settings/
+https://docs.djangoproject.com/en/2.1/ref/settings
 """
 
 import os
@@ -15,13 +10,29 @@ import warnings
 
 BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 
-HOST = "localhost"
-SECRET_KEY = "---"
-DEBUG = True
-ALLOWED_HOSTS = []
-DEFAULT_FROM_EMAIL = '[email protected]'
-USE_PAYMENTS = False
-REGISTRATION_OPEN = True
+
+def envbool(s, default):
+    v = os.getenv(s, default=default)
+    if v not in ("", "True", "False"):
+        msg = "Unexpected value %s=%s, use 'True' or 'False'" % (s, v)
+        raise Exception(msg)
+    return v == "True"
+
+
+def envint(s, default):
+    v = os.getenv(s, default)
+    if v == "None":
+        return None
+
+    return int(v)
+
+
+SECRET_KEY = os.getenv("SECRET_KEY", "---")
+DEBUG = envbool("DEBUG", "True")
+ALLOWED_HOSTS = os.getenv("ALLOWED_HOSTS", "*").split(",")
+DEFAULT_FROM_EMAIL = os.getenv("DEFAULT_FROM_EMAIL", "[email protected]")
+USE_PAYMENTS = envbool("DEBUG", "False")
+REGISTRATION_OPEN = envbool("DEBUG", "True")
 
 
 INSTALLED_APPS = (
@@ -90,28 +101,35 @@ DATABASES = {
 
 # You can switch database engine to postgres or mysql using environment
 # variable 'DB'. Travis CI does this.
-if os.environ.get("DB") == "postgres":
+if os.getenv("DB") == "postgres":
     DATABASES = {
         'default': {
             'ENGINE': 'django.db.backends.postgresql',
-            'USER': 'postgres',
-            'NAME': 'hc',
-            'TEST': {'CHARSET': 'UTF8'}
+            'HOST': os.getenv("DB_HOST", ""),
+            'PORT': os.getenv("DB_PORT", ""),
+            'NAME': os.getenv("DB_NAME", "hc"),
+            'USER': os.getenv("DB_USER", "postgres"),
+            'PASSWORD': os.getenv("DB_PASSWORD", ""),
+            'CONN_MAX_AGE': envint("DB_CONN_MAX_AGE", "0"),
+            'TEST': {'CHARSET': 'UTF8'},
+            'OPTIONS': {
+                "sslmode": os.getenv("DB_SSLMODE", "prefer"),
+                "target_session_attrs": os.getenv("DB_TARGET_SESSION_ATTRS", "read-write")
+            }
         }
     }
 
-if os.environ.get("DB") == "mysql":
+if os.getenv("DB") == "mysql":
     DATABASES = {
         'default': {
             'ENGINE': 'django.db.backends.mysql',
-            'USER': 'root',
-            'NAME': 'hc',
+            'NAME': os.getenv("DB_NAME", "hc"),
+            'USER': os.getenv("DB_USER", "root"),
+            'PASSWORD': os.getenv("DB_PASSWORD", ""),
             'TEST': {'CHARSET': 'UTF8'}
         }
     }
 
-LANGUAGE_CODE = 'en-us'
-
 TIME_ZONE = 'UTC'
 
 USE_I18N = True
@@ -120,10 +138,11 @@ USE_L10N = True
 
 USE_TZ = True
 
-SITE_ROOT = "http://localhost:8000"
-SITE_NAME = MASTER_BADGE_LABEL = "Mychecks"
-PING_ENDPOINT = SITE_ROOT + "/ping/"
-PING_EMAIL_DOMAIN = HOST
+SITE_ROOT = os.getenv("SITE_ROOT", "http://localhost:8000")
+SITE_NAME = os.getenv("SITE_NAME", "Mychecks")
+MASTER_BADGE_LABEL = os.getenv("MASTER_BADGE_LABEL", SITE_NAME)
+PING_ENDPOINT = os.getenv("PING_ENDPOINT", SITE_ROOT + "/ping/")
+PING_EMAIL_DOMAIN = os.getenv("PING_EMAIL_DOMAIN", "localhost")
 STATIC_URL = '/static/'
 STATICFILES_DIRS = [os.path.join(BASE_DIR, "static")]
 STATIC_ROOT = os.path.join(BASE_DIR, 'static-collected')
@@ -135,42 +154,42 @@ STATICFILES_FINDERS = (
 COMPRESS_OFFLINE = True
 COMPRESS_CSS_HASHING_METHOD = "content"
 
-# Discord integration -- override these in local_settings
-DISCORD_CLIENT_ID = None
-DISCORD_CLIENT_SECRET = None
+# Discord integration
+DISCORD_CLIENT_ID = os.getenv("DISCORD_CLIENT_ID")
+DISCORD_CLIENT_SECRET = os.getenv("DISCORD_CLIENT_SECRET")
 
-# Slack integration -- override these in local_settings
-SLACK_CLIENT_ID = None
-SLACK_CLIENT_SECRET = None
+# Slack integration
+SLACK_CLIENT_ID = os.getenv("SLACK_CLIENT_ID")
+SLACK_CLIENT_SECRET = os.getenv("SLACK_CLIENT_SECRET")
 
-# Pushover integration -- override these in local_settings
-PUSHOVER_API_TOKEN = None
-PUSHOVER_SUBSCRIPTION_URL = None
-PUSHOVER_EMERGENCY_RETRY_DELAY = 300
-PUSHOVER_EMERGENCY_EXPIRATION = 86400
+# Pushover integration
+PUSHOVER_API_TOKEN = os.getenv("PUSHOVER_API_TOKEN")
+PUSHOVER_SUBSCRIPTION_URL = os.getenv("PUSHOVER_SUBSCRIPTION_URL")
+PUSHOVER_EMERGENCY_RETRY_DELAY = int(os.getenv("PUSHOVER_EMERGENCY_RETRY_DELAY", "300"))
+PUSHOVER_EMERGENCY_EXPIRATION = int(os.getenv("PUSHOVER_EMERGENCY_EXPIRATION", "86400"))
 
-# Pushbullet integration -- override these in local_settings
-PUSHBULLET_CLIENT_ID = None
-PUSHBULLET_CLIENT_SECRET = None
+# Pushbullet integration
+PUSHBULLET_CLIENT_ID = os.getenv("PUSHBULLET_CLIENT_ID")
+PUSHBULLET_CLIENT_SECRET = os.getenv("PUSHBULLET_CLIENT_SECRET")
 
 # Telegram integration -- override in local_settings.py
-TELEGRAM_BOT_NAME = "ExampleBot"
-TELEGRAM_TOKEN = None
+TELEGRAM_BOT_NAME = os.getenv("TELEGRAM_BOT_NAME", "ExampleBot")
+TELEGRAM_TOKEN = os.getenv("TELEGRAM_TOKEN")
 
-# SMS (Twilio) integration -- override in local_settings.py
-TWILIO_ACCOUNT = None
-TWILIO_AUTH = None
-TWILIO_FROM = None
+# SMS (Twilio) integration
+TWILIO_ACCOUNT = os.getenv("TWILIO_ACCOUNT")
+TWILIO_AUTH = os.getenv("TWILIO_AUTH")
+TWILIO_FROM = os.getenv("TWILIO_FROM")
 
 # PagerDuty
-PD_VENDOR_KEY = None
+PD_VENDOR_KEY = os.getenv("PD_VENDOR_KEY")
 
 # Zendesk
-ZENDESK_CLIENT_ID = None
-ZENDESK_CLIENT_SECRET = None
+ZENDESK_CLIENT_ID = os.getenv("ZENDESK_CLIENT_ID")
+ZENDESK_CLIENT_SECRET = os.getenv("ZENDESK_CLIENT_ID")
 
 # Trello
-TRELLO_APP_KEY = None
+TRELLO_APP_KEY = os.getenv("TRELLO_APP_KEY")
 
 if os.path.exists(os.path.join(BASE_DIR, "hc/local_settings.py")):
     from .local_settings import *