commit 6f59fa0b0a2c84b8326f3cb8f237ffa5372e571a
Author: Knut Ahlers <knut@ahlers.me>
Date:   Sat Jul 11 18:20:49 2020 +0200

    Initial version

diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..85c55eb
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,2 @@
+.env
+.venv
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3c1dad2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+config.yml
+.env
+.venv
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..4e5df4d
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,13 @@
+FROM python:alpine
+
+COPY requirements.txt /src/requirements.txt
+WORKDIR /src
+
+RUN set -ex \
+ && pip install -r /src/requirements.txt
+
+VOLUME ["/config"]
+ENV CONFIG_PATH=/config/config.yml
+
+COPY . /src
+CMD ["/usr/local/bin/python3", "main.py"]
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..745b174
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,11 @@
+default:
+
+clean:
+	rm -rf .venv
+
+freeze: testenv
+	./.venv/bin/pip freeze >requirements.txt
+
+testenv: clean
+	python -m venv .venv
+	./.venv/bin/pip install -r requirements.txt
diff --git a/config_sample.yml b/config_sample.yml
new file mode 100644
index 0000000..f21acfb
--- /dev/null
+++ b/config_sample.yml
@@ -0,0 +1,21 @@
+---
+
+influx_db: 'mqtt_map'
+
+subscriptions:
+
+  tele/kettle/SENSOR:
+    - metric: power
+      tags:
+        device: kettle
+      transform: !lambda "x: json.loads(x)['ENERGY']['Power']"
+    - metric: current
+      tags:
+        device: kettle
+      transform: !lambda "x: json.loads(x)['ENERGY']['Current']"
+    - metric: voltage
+      tags:
+        device: kettle
+      transform: !lambda "x: json.loads(x)['ENERGY']['Voltage']"
+
+...
diff --git a/influx.py b/influx.py
new file mode 100644
index 0000000..8d081ab
--- /dev/null
+++ b/influx.py
@@ -0,0 +1,33 @@
+from influxdb import InfluxDBClient
+import vault
+
+
+class Influx():
+
+    def __init__(self, database):
+        cfg = vault.read_data('secret/mqtt2influx/influxdb')
+
+        self.database = database
+        self.client = InfluxDBClient(cfg['host'], cfg['port'],
+                                     cfg['user'], cfg['pass'], self.database)
+
+    def submit(self, body):
+        """
+        submit("mydatabase", [
+            {
+                "measurement": "cpu_load_short",
+                "tags": {
+                    "host": "server01",
+                    "region": "us-west"
+                },
+                "time": "2009-11-10T23:00:00Z",
+                "fields": {
+                    "Float_value": 0.64,
+                    "Int_value": 3,
+                    "String_value": "Text",
+                    "Bool_value": True
+                }
+            }
+        ])
+        """
+        self.client.write_points(body, database=self.database)
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..a9a28bd
--- /dev/null
+++ b/main.py
@@ -0,0 +1,104 @@
+import logging
+import os
+import paho.mqtt.client as mqtt
+import yaml
+
+from yaml_lambda import *
+from influx import Influx
+import vault
+
+
+class MQTT2InfluxDB():
+
+    def __init__(self, config_path='config.yml'):
+        with open(config_path) as cfg_file:
+            self.config = yaml.safe_load(cfg_file)
+
+        self.influx = Influx(self.obj_get(
+            self.config, 'influx_db', 'mqtt2influxdb'))
+
+    def obj_get(self, obj, key, default=None):
+        if key in obj:
+            return obj[key]
+        return default
+
+    def on_connect(self, client, userdata, flags, rc):
+        topics = [(topic, 1) for topic in self.config['subscriptions'].keys()]
+        result, _ = client.subscribe(topics)
+
+        if result != mqtt.MQTT_ERR_SUCCESS:
+            raise(Exception('MQTT subscribe failed: {}'.format(result)))
+
+        logging.info('MQTT connected and subscribed')
+
+    def on_message(self, client, userdata, msg):
+        points = []
+
+        for processor in self.obj_get(self.config['subscriptions'], msg.topic, []):
+            tffn = self.obj_get(processor, 'transform',
+                                YAMLLambda('x: float(x)'))
+            value = tffn.run(msg.payload)
+
+            points.append({
+                'measurement': processor['metric'],
+                'tags': self.obj_get(processor, 'tags', {}),
+                'fields': {
+                    'value': value,
+                },
+            })
+
+            logging.debug(
+                'MQTT Message received: topic={topic} metric={metric} value={value}'.format(
+                    topic=msg.topic,
+                    metric=processor['metric'],
+                    value=value,
+                ))
+
+        if len(points) > 0:
+            self.influx.submit(points)
+
+    def run(self):
+        client = mqtt.Client()
+        client.enable_logger()
+        client.on_connect = self.on_connect
+        client.on_message = self.on_message
+
+        mqtt_config = vault.read_data('secret/mqtt2influx/mqtt')
+
+        client.username_pw_set(
+            self.obj_get(mqtt_config, 'user', self.obj_get(
+                os.environ, 'MQTT_USER')),
+            self.obj_get(mqtt_config, 'pass', self.obj_get(
+                os.environ, 'MQTT_PASS')),
+        )
+
+        logging.debug('Connecting to MQTT broker...')
+
+        client.connect(
+            self.obj_get(mqtt_config, 'host', self.obj_get(
+                os.environ, 'MQTT_HOST')),
+            port=self.obj_get(mqtt_config, 'port', self.obj_get(
+                os.environ, 'MQTT_PORT', 1883)),
+            keepalive=10,
+        )
+
+        client.loop_forever()
+
+
+if __name__ == '__main__':
+    loglevel = logging.INFO
+    if 'LOG_LEVEL' in os.environ and os.environ['LOG_LEVEL'] == 'DEBUG':
+        loglevel = logging.DEBUG
+
+    configpath = 'config.yml'
+    if 'CONFIG_PATH' in os.environ:
+        configpath = os.environ['CONFIG_PATH']
+
+    logging.basicConfig(
+        datefmt='%m/%d/%Y %I:%M:%S %p',
+        format='[%(asctime)s][%(levelname)s] %(message)s',
+        level=loglevel,
+    )
+
+    inst = MQTT2InfluxDB(configpath)
+    inst.run()
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..745a862
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,4 @@
+paho-mqtt
+PyYAML
+hvac
+influxdb
diff --git a/vault.py b/vault.py
new file mode 100644
index 0000000..70c4e39
--- /dev/null
+++ b/vault.py
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+import hvac
+import os
+
+if not 'VAULT_ADDR' in os.environ or not 'VAULT_ROLE_ID' in os.environ:
+    raise Exception('VAULT_ADDR or VAULT_ROLE_ID are missing')
+
+vault = hvac.Client(os.environ['VAULT_ADDR'])
+auth = vault.auth_approle(os.environ['VAULT_ROLE_ID'])
+if 'auth' in auth and 'client_token' in auth['auth']:
+    vault.token = auth['auth']['client_token']
+else:
+    raise Exception('Authorization to Vault failed!')
+
+
+def read_data(key):
+    resp = vault.read(key)
+    if 'data' not in resp:
+        raise Exception('Unable to read configuration')
+    return resp['data']
diff --git a/yaml_lambda.py b/yaml_lambda.py
new file mode 100644
index 0000000..42eacf7
--- /dev/null
+++ b/yaml_lambda.py
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+import json
+import yaml
+
+
+class YAMLLambda(yaml.YAMLObject):
+    yaml_tag = '!lambda'
+
+    def __init__(self, lambda_code):
+        self.code = lambda_code
+
+    def run(self, in_value):
+        return eval('lambda {}'.format(self.code))(in_value)
+
+    @classmethod
+    def from_yaml(cls, loader, node):
+        return YAMLLambda(node.value)
+
+    @classmethod
+    def to_yaml(cls, dumper, data):
+        return dumper.represent_scalar(cls.yaml_tag, data.code)
+
+
+yaml.SafeLoader.add_constructor('!lambda', YAMLLambda.from_yaml)
+yaml.SafeDumper.add_multi_representer(YAMLLambda, YAMLLambda.to_yaml)