Load configuration from a yaml file

7 files changed, 94 insertions, 3 deletions

diff --git a/.gitignore b/.gitignore
index 1dec1e4..4feffad 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,7 +3,6 @@
 
 db.sqlite3
 
-kerbana.toml
-kerbana_tests.toml
+kerbana.yaml
 
 .*.sw?
diff --git a/kerbana/config.py b/kerbana/config.py
new file mode 100644
index 0000000..03664c0
--- /dev/null
+++ b/kerbana/config.py
@@ -0,0 +1,59 @@
+import logging
+import os
+import sys
+
+import strictyaml
+
+
+log = logging.getLogger(__name__)
+
+
+def read_from_yaml(fp):
+    data = strictyaml.load(fp.read())
+    for k, v in data.data.items():
+        setattr(sys.modules[__name__], k, v)
+
+
+conf_file = "/etc/kerbana/kerbana.yaml"
+try:
+    with open(conf_file) as fp:
+        read_from_yaml(fp)
+        log.info("Configuration read from %s", conf_file)
+except FileNotFoundError:
+    log.info("File %s not found.", conf_file)
+except strictyaml.YAMLError as error:
+    log.error("Syntax error in %s", conf_file)
+    log.error(error)
+    sys.exit(1)
+
+
+conf_file = os.path.join(
+    os.path.dirname(os.path.abspath(__file__)),
+    "..",
+    "kerbana.yaml"
+)
+try:
+    with open(conf_file) as fp:
+        read_from_yaml(fp)
+        log.info("Configuration read from %s", conf_file)
+except FileNotFoundError:
+    log.info("File %s not found.", conf_file)
+except strictyaml.YAMLError as error:
+    log.error("Syntax error in %s", conf_file)
+    log.error(error)
+    sys.exit(1)
+
+conf_file = os.environ.get("KERBANA_CONFIG")
+if conf_file:
+    try:
+        with open(conf_file) as fp:
+            read_from_yaml(fp)
+            log.info("Configuration read from %s", conf_file)
+    except FileNotFoundError:
+        log.info("File %s (as in $KERBANA_CONFIG) not found.", conf_file)
+    except strictyaml.YAMLError as error:
+        log.error("Syntax error in %s (as in $KERBANA_CONFIG)", conf_file)
+        log.error(error)
+        sys.exit(1)
+else:
+    log.info("Variable KERBANA_CONFIG not available")
diff --git a/kerbana/settings.py b/kerbana/settings.py
index f0ba3f2..9cccae0 100644
--- a/kerbana/settings.py
+++ b/kerbana/settings.py
@@ -125,8 +125,14 @@ STATIC_URL = '/static/'
 
 DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
 
-MQTT_SERVER = "test.mosquitto.org"
+# MQTT settings
+# There is a MQTT server at test.mosquitto.org which can be used to try
+# out kerbana, but please read the terms of use before using it in
+# production.
+MQTT_SERVER = "mqtt.invalid.org"
 MQTT_PORT = 1883
 MQTT_USER = None
 MQTT_PASSWORD = None
 MQTT_TOPIC = "kerbana/#"
+
+from .config import *
diff --git a/kerbana/tests/__init__.py b/kerbana/tests/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/kerbana/tests/__init__.py
diff --git a/kerbana/tests/data/invalid.yaml b/kerbana/tests/data/invalid.yaml
new file mode 100644
index 0000000..e29a5d7
--- /dev/null
+++ b/kerbana/tests/data/invalid.yaml
@@ -0,0 +1 @@
+SETTING: "value": "invalid"
diff --git a/kerbana/tests/data/valid.yaml b/kerbana/tests/data/valid.yaml
new file mode 100644
index 0000000..186d59b
--- /dev/null
+++ b/kerbana/tests/data/valid.yaml
@@ -0,0 +1 @@
+SETTING: "value"
diff --git a/kerbana/tests/test_config.py b/kerbana/tests/test_config.py
new file mode 100644
index 0000000..43b611d
--- /dev/null
+++ b/kerbana/tests/test_config.py
@@ -0,0 +1,25 @@
+import importlib
+import os
+
+from django.test import TestCase
+
+import kerbana.config
+
+class TestConfig(TestCase):
+    def test_config_from_env(self):
+        os.environ["KERBANA_CONFIG"] = os.path.join(
+            os.path.dirname(os.path.abspath(__file__)),
+            "data",
+            "valid.yaml"
+        )
+        importlib.reload(kerbana.config)
+        self.assertEqual(kerbana.config.SETTING, "value")
+
+    def test_config_invalid(self):
+        os.environ["KERBANA_CONFIG"] = os.path.join(
+            os.path.dirname(os.path.abspath(__file__)),
+            "data",
+            "invalid.yaml"
+        )
+        with self.assertRaises(SystemExit):
+            importlib.reload(kerbana.config)