From bca665ade308027a5ce4b143e6d99a073a262727 Mon Sep 17 00:00:00 2001
From: Michael Kotten <michaelkotten@gmail.com>
Date: Wed, 22 Jun 2022 08:27:36 +0200
Subject: [PATCH] adds /metrics endpoint with prometheus format

---
 README.md                      |  1 +
 SunGather/exports/webserver.py | 32 ++++++++++++++++++++++----------
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index 2ec8bbc..a2b6245 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,7 @@ Has multiple export locations out of the box:
 * MQTT - Load into MQTT, and optionally Home Assistance including Discovery
 * PVOutput - Load into PVOutput.org
 * InfluxDB - Load data directly into InfluxDB (v1.8 or v2.x)
+* Prometheus - Scrape from /metrics endpoint
 * Simple webserver showing collected data
 * Rasberry Pi Docker support
 * and more coming....
diff --git a/SunGather/exports/webserver.py b/SunGather/exports/webserver.py
index 2f6b88b..3200918 100644
--- a/SunGather/exports/webserver.py
+++ b/SunGather/exports/webserver.py
@@ -7,6 +7,7 @@ import logging
 
 class export_webserver(object):
     html_body = "Pending Data Retrieval"
+    metrics = ""
     def __init__(self):
         False
 
@@ -25,9 +26,12 @@ class export_webserver(object):
 
     def publish(self, inverter):
         body = "<h3>Sungather v" + __version__ + "</h3></p><table><th>Address</th><tr><th>Register</th><th>Value</th></tr>"
+        metrics = ""
         for register, value in inverter.latest_scrape.items():
-            body = body + f"<tr><td>{str(inverter.getRegisterAddress(register))}</td><td>{str(register)}</td><td>{str(value)} {str(inverter.getRegisterUnit(register))}</td></tr>"
+            body += f"<tr><td>{str(inverter.getRegisterAddress(register))}</td><td>{str(register)}</td><td>{str(value)} {str(inverter.getRegisterUnit(register))}</td></tr>"
+            metrics += f"{str(register)}{{address=\"{str(inverter.getRegisterAddress(register))}\", unit=\"{str(inverter.getRegisterUnit(register))}\"}} {str(value)}\n"
         export_webserver.html_body = body + f"</table><p>Total {len(inverter.latest_scrape)} registers"
+        export_webserver.metrics = metrics
 
         body = "</p></p><table><tr><th>Configuration</th><th>Value</th></tr>"
         for setting, value in inverter.client_config.items():
@@ -35,18 +39,26 @@ class export_webserver(object):
         for setting, value in inverter.inverter_config.items():
             body = body + f"<tr><td>{str(setting)}</td><td>{str(value)}</td></tr>"
         export_webserver.html_body = export_webserver.html_body + body + f"</table></p>"
-            
+
         return True
 
 class MyServer(BaseHTTPRequestHandler):
     def do_GET(self):
-        self.send_response(200)
-        self.send_header("Content-type", "text/html")
-        self.end_headers()
-        self.wfile.write(bytes("<html><head><title>SunGather</title><meta charset='UTF-8'><meta http-equiv='refresh' content='15'></head>", "utf-8"))
-        self.wfile.write(bytes("<body>", "utf-8"))
-        self.wfile.write(bytes(export_webserver.html_body, "utf-8"))
-        self.wfile.write(bytes("</table>", "utf-8"))
-        self.wfile.write(bytes("</body></html>", "utf-8"))
+        if self.path == '/metrics':
+            self.send_response(200)
+            self.send_header("Content-type", "text/plain")
+            self.end_headers()
+            self.wfile.write(bytes(export_webserver.metrics, "utf-8"))
+        else:
+            self.send_response(200)
+            self.send_header("Content-type", "text/html")
+            self.end_headers()
+            self.wfile.write(bytes("<html><head><title>SunGather</title><meta charset='UTF-8'><meta http-equiv='refresh' content='15'></head>", "utf-8"))
+            self.wfile.write(bytes("<body>", "utf-8"))
+            self.wfile.write(bytes(export_webserver.html_body, "utf-8"))
+            self.wfile.write(bytes("</table>", "utf-8"))
+            self.wfile.write(bytes("</body></html>", "utf-8"))
+
+
     def log_message(self, format, *args):
         pass