Record postgresql version

clients/record_postgresql_version

@@ -0,0 +1,36 @@
+#!/usr/bin/python3
+import re
+import subprocess
+import time
+
+import ltsdb_record
+
+p = subprocess.run(["psql", "-c", "select version()", "-A", "-t", "-X", "-q",],
+                   stdout=subprocess.PIPE, universal_newlines=True)
+
+# This works only for PostgreSQL 10.x and above. I don't expect to encounter
+# older versions any more.
+m = re.match(r"^PostgreSQL (\d+).(\d+) ", p.stdout)
+if m:
+    version = int(m.group(1)) + int(m.group(2)) / 100
+
+report0 = []
+report0.append({ "measure": "postgresql_version", "unit": "version", "value":
+version})
+now = time.time()
+report = [
+    {
+        "description": {
+            "hostname": ltsdb_record.node,
+            "measure": r["measure"],
+            "unit": r["unit"]
+        },
+        "data": [
+            [now, r["value"]]
+        ]
+    }
+    for r in report0
+]
+
+success = ltsdb_record.record_observations(report)
+exit(1 - success)