Add info metric and prep release

CHANGELOG.md

@@ -0,0 +1,21 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+
+### Changed
+
+### Deprecated
+
+### Removed
+
+### Fixed
+
+### Security
+
+## [1.0.0] - 2020-06-29

README.md

@@ -1,14 +1,25 @@
 # Prometheus ESP8266 DHT Exporter
 
+[![GitHub release](https://img.shields.io/github/v/release/HON95/prometheus-esp8266-dht-exporter?label=Version)](https://github.com/HON95/prometheus-esp8266-dht-exporter/releases)
+
 A Prometheus exporter for IoT temperature and humidity measurements, using an ESP8266 (Arduino-compatible) with a Wi-Fi module and a DHT (temperature + humidity) sensor.
 
+## Metrics
+
+| Metric | Description | Unit |
+| - | - | - |
+| iot_info | Metadata about the device. | |
+| iot_air_humidity_percent | Air humidity. | `%` |
+| iot_air_temperature_celsius | Air temperature. | `°C` |
+| iot_air_heat_index_celsius | Apparent air temperature, based on temperature and humidity. | `°C` |
+
 ## Hardware
 
-ESP8266 board: [WEMOS D1 Mini](https://wiki.wemos.cc/products:d1:d1_mini) (ESP8266)
+ESP8266-based board: [WEMOS D1 Mini](https://wiki.wemos.cc/products:d1:d1_mini)
 
 DHT sensor: [Wemos DHT Shield](https://wiki.wemos.cc/products:retired:dht_shield_v1.0.0) (DHT11)
 
-## Requirements
+## Software
 
 - [Arduino IDE](https://www.arduino.cc/en/Main/Software)
     - Download and install.
@@ -27,10 +38,12 @@ This uses the Arduino IDE.
     - WEMOS D1 Mini uses board "WeMoS D1 R2 & mini".
 1. Build and upload using the Arduino IDE.
 
-## Metrics
+## Version
 
-| Metric | Description | Unit |
+See `src/version.h`.
-| - | - | - |
+
-| iot_air_humidity_percent | Air humidity. | `%` |
+It's set manually since no build tools (or CI) other than the Arduino IDE is used.
-| iot_air_temperature_celsius | Air temperature. | `°C` |
+
-| iot_air_heat_index_celsius | Apparent air temperature, based on temperature and humidity. | `°C` |
+## License
+
+GNU General Public License version 3 (GPLv3).

src/config.default.h

@@ -2,6 +2,10 @@
 
 // Debug mode is enabled if not zero
 #define DEBUG_MODE 0
+// Board name
+#define BOARD_NAME "ESP8266"
+// DHT sensor name (should be the same)
+#define DHT_NAME "DHT11"
 // DHT sensor type
 #define DHT_TYPE DHT11
 // DHT pin

src/src.ino

@@ -4,6 +4,7 @@
 #include <DHTesp.h>
 
 #include "config.h"
+#include "version.h"
 
 enum LogLevel {
     DEBUG,
@@ -88,6 +89,10 @@ void handle_http_home_client() {
 void handle_http_metrics_client() {
     static size_t const BUFSIZE = 1024;
     static char const *response_template =
+        "# HELP iot_info Metadata about the device.\n"
+        "# TYPE iot_info gauge\n"
+        "# UNIT iot_info \n"
+        "iot_info{version=\"%s\",board=\"%s\",sensor=\"%s\"} 1\n"
         "# HELP iot_air_humidity_percent Air humidity.\n"
         "# TYPE iot_air_humidity_percent gauge\n"
         "# UNIT iot_air_humidity_percent %%\n"
@@ -108,7 +113,7 @@ void handle_http_metrics_client() {
     }
 
     char response[BUFSIZE];
-    snprintf(response, BUFSIZE, response_template, humidity, temperature, heat_index);
+    snprintf(response, BUFSIZE, response_template, VERSION, BOARD_NAME, DHT_NAME, humidity, temperature, heat_index);
     http_server.send(200, "text/plain; charset=utf-8", response);
 }
 

src/version.h

@@ -0,0 +1,3 @@
+#pragma once
+
+#define VERSION "1.0.0"