Record number of connections per dataabase from pg_stat_activity

clients/record_pg_stat_activity

@@ -0,0 +1,60 @@
+#!/usr/bin/python3
+
+import time
+import re
+
+import psycopg2
+import psycopg2.extras
+
+import ltsdb_record
+
+db = psycopg2.connect() # We only get useful results if we are postgres, but for testing we can be any user
+
+csr = db.cursor(cursor_factory=psycopg2.extras.NamedTupleCursor)
+csr.execute(
+        """
+        select datname, count(*)
+        from pg_stat_activity
+        where backend_type = 'client backend' group by datname order by datname
+        """)
+
+total = 0
+
+now = time.time()
+report0 = []
+for r in csr:
+        report0.append(
+                    {
+                        "measure": "connections",
+                        "database": r.datname,
+                        "unit": "connections",
+                        "value": r.count
+                    }
+                )
+        total += r.count
+report0.append(
+            {
+                "measure": "connections",
+                "database": "ALL",
+                "unit": "connections",
+                "value": total
+            }
+        )
+
+report = [
+    {
+        "description": {
+            "hostname": ltsdb_record.node,
+            "measure": r["measure"],
+            "database": r["database"],
+            "unit": r["unit"]
+        },
+        "data": [
+            [now, r["value"]]
+        ]
+    }
+    for r in report0
+]
+
+success = ltsdb_record.record_observations(report)
+exit(1 - success)