Add latest version metric

* Add a special handler for latest version info

* Add initial latest version items/triggers to the Zabbix template

src/pgmon.py

@@ -699,6 +699,18 @@ class SimpleHTTPRequestHandler(BaseHTTPRequestHandler):
         if metric_name == "agent_version":
             self._reply(200, VERSION)
             return
+        elif metric_name == "latest_version_info":
+            try:
+                get_latest_version()
+                self._reply(
+                    200,
+                    json.dumps(
+                        {"latest": latest_version, "supported": 1 if release_supported else 0}
+                    ),
+                )
+            except LatestVersionCheckError as e:
+                log.error("Failed to retrieve latest version information: {}".format(e))
+                self._reply(503, "Failed to retrieve latest version info")
 
         # Note: parse_qs returns the values as a list.  Since we always expect
         #       single values, just grab the first from each.

zabbix_templates/pgmon_templates.yaml

@@ -11,6 +11,39 @@ zabbix_export:
       groups:
         - name: 'My Templates'
       items:
+        - uuid: de1fa757395440118026f4c7a7c4ebbe
+          name: 'PostgreSQL latest supported version'
+          type: DEPENDENT
+          key: pgmon.release.latest
+          delay: '0'
+          preprocessing:
+            - type: JSONPATH
+              parameters:
+                - $.latest
+          master_item:
+            key: 'pgmon[latest_version_info]'
+          tags:
+            - tag: Application
+              value: PostgreSQL
+        - uuid: e1a003317bc043908ee0803704a6e1d0
+          name: 'PostgreSQL release support status'
+          type: DEPENDENT
+          key: pgmon.release.supported
+          delay: '0'
+          preprocessing:
+            - type: JSONPATH
+              parameters:
+                - $.supported
+          master_item:
+            key: 'pgmon[latest_version_info]'
+          tags:
+            - tag: Application
+              value: PostgreSQL
+          triggers:
+            - uuid: 88eac74402d64e7cb853e8cb505b1939
+              expression: 'last(/PostgreSQL by pgmon/pgmon.release.supported)<>1'
+              name: 'PostgreSQL major release is lo longer supported'
+              priority: INFO
         - uuid: 763920af8da84db8a9a2667d9653cb21
           name: 'PostgreSQL Agent Version'
           type: HTTP_AGENT
@@ -24,6 +57,19 @@ zabbix_export:
           tags:
             - tag: Application
               value: PostgreSQL
+        - uuid: d890e395fbbc4f2bacbd50e7321fcb9f
+          name: 'PostgreSQL latest version info'
+          type: HTTP_AGENT
+          key: 'pgmon[latest_version_info]'
+          delay: 12h
+          history: '0'
+          value_type: TEXT
+          trends: '0'
+          description: 'Information about the latest PostgreSQL version in the current series'
+          url: 'http://localhost:{$AGENT_PORT}/version'
+          tags:
+            - tag: Application
+              value: PostgreSQL
         - uuid: 8706eccb7edc4fa394f552fc31f401a9
           name: 'Max Frozen XID Age'
           type: HTTP_AGENT
@@ -1017,3 +1063,22 @@ zabbix_export:
                     - type: STRING
                       name: reference
                       value: XSCMZ
+  triggers:
+    - uuid: 94ce93c828aa46b4bd4f3732fc7090c6
+      expression: 'last(/PostgreSQL by pgmon/pgmon.release.latest) - last(/PostgreSQL by pgmon/pgmon[version]) >= 1'
+      name: 'PostgreSQL is at least 1 version behind'
+      priority: INFO
+      dependencies:
+        - name: 'PostgreSQL is at least 2 version behind'
+          expression: 'last(/PostgreSQL by pgmon/pgmon.release.latest) - last(/PostgreSQL by pgmon/pgmon[version]) >= 2'
+    - uuid: 2701bcd1223c4ee787f3eca30288e6c6
+      expression: 'last(/PostgreSQL by pgmon/pgmon.release.latest) - last(/PostgreSQL by pgmon/pgmon[version]) >= 2'
+      name: 'PostgreSQL is at least 2 version behind'
+      priority: INFO
+      dependencies:
+        - name: 'PostgreSQL is at least 3 version behind'
+          expression: 'last(/PostgreSQL by pgmon/pgmon.release.latest) - last(/PostgreSQL by pgmon/pgmon[version]) >= 3'
+    - uuid: 3c9adbe8b6f84b3788c6a3e513075df5
+      expression: 'last(/PostgreSQL by pgmon/pgmon.release.latest) - last(/PostgreSQL by pgmon/pgmon[version]) >= 3'
+      name: 'PostgreSQL is at least 3 version behind'
+      priority: INFO